Seminars and Colloquia at ESO Garching and on the campus

December 2014

19/12/14 (Friday)
14:00, MPA Old Lecture Hall 401 | ESO Garching
Bayes Forum
Talk — On the on/off problem
Max Knoetig (Institute for Particle Physics, ETH Zuerich)
18/12/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Dwarf Galaxies as Cosmological Probes
Julio Navarro (University of Victoria, Canada)
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Abstract

A prime challenge to our understanding of galaxy formation
concerns the scarcity of dwarf galaxies compared with the numerous
low-mass halos expected in the current L-CDM paradigm. This is usually
accounted for by assuming that energetic feedback from evolving stars
confines dwarf galaxy formation to relatively massive halos spanning a
narrow mass range. I will highlight a number of observations that may
be used to test this assumption and discuss the puzzles and challenges
that arise from this analysis. I will also discuss a number of
challenges that L-CDM faces on the scale of dwarf galaxies and their
possible resolutions.

Video

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17/12/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Inferring past and present cosmic structures from observations
Jens Jasche (TUM)

Abstract

Current and future cosmological surveys produce huge amounts of data. An efficient and accurate information processing technology is needed to analyse and interpret this data. Besides traditional systematics and uncertainties modern data analysis needs to account for the complex statistical properties of gravitationally evolved matter fields. It also has to provide corresponding uncertainty quantification. The analysis of the structure and evolution of our inhomogeneous Universe hence requires to solve non-linear statistical inference problems in very high dimensional parameter spaces. This talk addresses the problem of high dimensional Bayesian inference from cosmological data sets via the recently proposed BORG algorithm. Its method couples an approximate model of structure formation to an Hybrid Monte Carlo algorithm. This provides a fully probabilistic, physical model of the non-linearly evolved density field as probed by galaxy surveys. Besides highly accurate and detailed measurements of 3D cosmic density and velocity fields, this methodology also infers plausible formation histories for the observed large scale structure. Jens will give an overview over this promising path towards Bayesian chrono-cosmography, the subject of inferring the four dimensional state of our Universe from observations.

11:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
MPA Seminar
Talk — HI-to-H_2 Transitions and HI Column Densities in Galaxy Star-Forming Regions
Amiel Sternberg (Tel Aviv University)
16/12/14 (Tuesday)
14:00, MPA Old Lecture Hall 401 | ESO Garching
CarSem Seminar
Talk — Turning science into stories
Dr. Hanna Kotarba (Science journalist at ZDF)

Abstract

 

Science is not only the work on a particular topic, science is a way to

approach things. A scientist wants to know whatever the result is. On
contrary, most non-scientists need a strong reason to get interested.
This difference makes it so difficult to get a non-scientific audience
interested in scientific topics and work. However, there is one single
reason which is a strong reason for virtually all people: a good story.
But how to turn science into stories? In this talk, I will overview the
main tools of storytelling, the daily work of a science journalist, the
main difficulties scientists are confronted with turning to journalism
and the reasons why this work is nevertheless rewarding.

11:30, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Cosmology Seminar
Talk — Substructure shape and orbits and what they tell us about the Milky Way
Julio Navarro (University of Victoria, Canada)
11:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Cosmology Seminar
Talk — Kennicutt-Schmidt relation in the HI dominated regime
Sambit Roychowdhury (MPA)
10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Molecules at the Reionization Epoch - CO/H2 and OH/CO: From High Ionization to Low Metallicity
Shmuel Bialy (Tel Aviv University)

Abstract

I will discuss cold dense-gas interstellar chemistry down to very low metallicities (< ~ 10^{-3} times solar), and/or up to high driving ionization rates, appropriate for the cool ISM in low-metallicity dwarf galaxies and especially early enriched clouds at the reionization and Pop-II star formation era. I will focus on the behavior for H_2, CO, CH, OH, H_2O and O_2. I will show computations for shielded or partially shielded gas for steady-state conditions for a wide range of ionization parameters, zeta/n, and metallicties, Z'. The OH abundances are always maximal at the H-to-H conversion points, and large OH abundances persist at very low metallicities even when the hydrogen is predominantly atomic. Much of the cold dense ISM for the Pop-II generation may have been OH-dominated and atomic rather than CO-dominated and molecular.

15/12/14 (Monday)
17:15, LMU, Schellingstr. 4, Munich | ESO Garching
Muenchner Physik Kolloquium
Talk — Quantum optomechanics - a road to gravity?
Markus Aspelmeyer (University of Vienna)
12:00, MPE Old Seminar Room (MPE, Garching) | ESO Garching
MPE Seminar
Talk — Modelling photodissociation regions in galactic and extragalactic environments
Thomas Bisbas (University College London)
11:00, MPE Seminar Room 1.1.18b | ESO Garching
MPE Seminar
Talk — Why stellar feedback promotes disc formation in simulated galaxies
Hannah Uebler (MPA)
12/12/14 (Friday)
11:30, MPA Old Lecture Hall 401 | ESO Garching
High Energy Seminar
Talk — A numerical approach to the epoch of Helium reionization
Michele Compostella (MPA)
11:00, MPA Old Lecture Hall 401 | ESO Garching
High Energy Seminar
Talk — Transport of Cosmic Rays in the turbulent galactic magnetic fields
Giuseppe Di Bernardo (MPA)
11/12/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Inside-Out Planet Formation
Jonathan C. Tan (University of Florida)
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Abstract

The Kepler-discovered systems with tightly-packed inner planets (STIPs), typically with several planets of Earth to super-Earth masses on well-aligned, sub-AU orbits may host the most common type of planets in the Galaxy. They pose a great challenge for planet formation theories, which fall into two broad classes: (1) formation further out followed by migration; (2) formation in situ from a disk of gas and planetesimals. I review the pros and cons of these classes, before focusing on a new theory of sequential in situ formation from the inside-out via creation of successive gravitationally unstable rings fed from a continuous stream of small (~cm-m size) "pebbles," drifting inward via gas drag. Pebbles first collect at the pressure trap associated with the transition from a magnetorotational instability (MRI)-inactive ("dead zone") region to an inner MRI-active zone. A pebble ring builds up until it either becomes gravitationally unstable to form an Earth to super-Earth-mass planet directly or induces gradual planet formation via core accretion. The planet continues to accrete until it becomes massive enough to isolate itself from the accretion flow via gap opening. The process repeats with a new pebble ring gathering at the new pressure maximum associated with the retreating dead-zone boundary. I discuss the theory’s predictions for planetary masses, relative mass scalings with orbital radius, and minimum orbital separations, and their comparison with observed systems. Finally I speculate about potential causes of diversity of planetary system architectures, i.e. STIPs versus Solar System analogs.

Video

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14:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Special Talk
Talk — Robert Grosseteste: the first cosmologist?
Richard Bower (Durham University)
11:10, Library (ESO HQ, Garching) | ESO Garching
AGN Club
Talk — A sub-pc view of a Milky Way-like simulation
Eric Emsellem (ESO)
10/12/14 (Wednesday)
13:30, MPA Old Lecture Hall 401 | ESO Garching
Cosmology Seminar
Talk — Testing anisotropic universes with CMB data
Ophelia Fabre (IISER, Pune, India)
09/12/14 (Tuesday)
17:00, MPP, Freimann, Munich | ESO Garching
MPP Kolloquium
Talk — Recent progress in string-theoretic models of inflation
Arthur Hebecker (Heidelberg University)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Imfit: A fast, flexible new galaxy image-fitting program
Peter Erwin (MPE)

Abstract

I will discuss a new, open-source astronomical image-fitting program, specialized for galaxies, which is fast, flexible, and highly extensible. A key characteristic is an object-oriented design which allows new types of image components (2D surface-brightness functions) to be easily written and added to the program. Image functions provided with the program include the usual suspects for galaxy decompositions (Sersic, exponential, Gaussian), along with Core-Sersic and broken-exponential profiles, elliptical rings, and components which perform line-of-sight integration through 3D luminosity-density models of disks and rings seen at arbitrary inclinations. Minimization can be done using  standard chi^2 or Poisson-based maximum-likelihood statistics, which are appropriate for Poisson data in low-count regimes; different minimization algorithms allow trade-offs between speed and decreased sensitivity to local minima in the fit landscape.  I will also show that fitting low-S/N galaxy images by minimizing chi^2 can lead to biases in fitted parameter values, which are avoided if a Poisson ML statistic is used.

11:00, MPE Seminar Room 1.1.18a | ESO Garching
CAS Seminar
Talk — Molecular physics and astrochemistry: dancing together
Laurent Wiesenfeld (IPAG, Grenoble)
11:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Cosmology Seminar
Talk — Black hole feedback: from semi-analytic models to hydrodynamic simulation
Richard Bower (Durham University)
08/12/14 (Monday)
17:15, HS2, Physik TUM Garching | ESO Garching
Muenchner Physik Kolloquium
Talk — Probing the mechanical properties, interactions, and processing of DNA and RNA using single molecule torque and twist measurements
Jan Lipfert (Physik, LMU)
15:30, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
MPA Institute Seminar
Talk — Resolving stellar halos beyond the Local Group: the GHOSTS survey
Antonela Monachesi (MPA)
05/12/14 (Friday)
11:00, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — From data to theory at the cosmic dawn
Paul Sutter (Astronomical Observatory of Trieste)
04/12/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The Formation of Galaxy Clusters and the Evolution of Their Galaxies at 0<z<2
Adam Muzzin (IoA Cambridge, UK)
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Abstract

Galaxy clusters are the most massive structures in the universe and their
mass growth provides a unique test for cosmological models of structure
formation.  Clusters are also the location where many galaxies have
their star formation strongly truncated, and this process is still
poorly understood.  I will present new results on the growth of stellar
mass in clusters over ~10 Gyr of cosmic time which shows they are highly
concentrated at early times and are growing in an inside-out manner,
something that is not seen in most simulations.  I will also present new
constraints on the timescale and location for quenching of galaxies in
the cluster environment at early times.  These timescales are showing us
that the process by which clusters quench star formation is likely
evolving over cosmic time, and that we clearly need to invoke much more
sophisticated models of environmental quenching and feedback in galaxies
if we are to truly understand how galaxies evolve in high-density
environments.

Video

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13:30, MPE Seminar Room 1.1.18b | ESO Garching
Workshop — ERC Workshop
Julia Epp, Verena Fuchs/Kathrin Zahr (EU Buero)
03/12/14 (Wednesday)
11:00, MPA Old Lecture Hall 401 | ESO Garching
SESTAS
Talk — Reality Check: Gauging the Star-formation Efficiency with Realistic Synthetic Observations
Christine Koepferl (MPIA Heidelberg)
02/12/14 (Tuesday)
17:00, MPP, Freimann, Munich | ESO Garching
MPP Kolloquium
Talk — Deciphering the solar neutrino properties with Borexino
Giocacchino Ranucci (INFN, Milano)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — A complete census of mid-infrared spectral features in active galaxies
Evanthia Hatziminaoglou (ESO)

Abstract

I will present a comprehensive study of the mid-infrared spectral features in a sample
of almost 700 active galactic nuclei (AGN) with available spectra from the
Spitzer InfraRed Spectrograph (IRS). I will talk about the contribution of the
AGN and host galaxy components to the mid-infrared emission of the AGN, the strength and
peak wavelength of the silicate features at 9.7 and 18 micron and the implications on the
modelling of the dust in the torus, as well as the PAH features, present in many of the AGN
mid-infrared spectra.


11:00, MPA Old Lecture Hall 401 | ESO Garching
Cosmology Seminar
Talk — X-ray constraints on sterile neutrino dark matter
Mike Anderson (MPA)
01/12/14 (Monday)
17:15, LMU, Schellingstr. 4, Munich | ESO Garching
Muenchner Physik Kolloquium
Talk — Dark matter and Galaxy formation
Francoise Combes (Observatoire de Paris, LERMA)
15:30, MPA Old Lecture Hall 401 | ESO Garching
MPA Institute Seminar
Talk — The multi-scale nature of galactic star formation
Diederik Kruijssen (MPA)
12:00, MPA Old Lecture Hall 401 | ESO Garching
CAS Seminar
Talk — Electrification processes in cloud-forming ultra-cool stars and in planets
Christiane Helling (SUPA, University of St Andrews)
09:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching

November 2014

28/11/14 (Friday)
11:00, MPA Old Lecture Hall 401 | ESO Garching
High Energy Seminar
Talk — Black Holes in Centaurus A
Mark Burke (MPA)
11:00, MPA Old Lecture Hall 401 | ESO Garching
High Energy Seminar
Talk — Simple methods for estimating masses of elliptical galaxies
Natalya Lyskova (MPA)
27/11/14 (Thursday)
16:15, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Searching for the origins of galaxy bimodality
Vivienne Wild (University of St. Andrews, UK)

Abstract

Understanding how and why galaxies form and evolve is one of the most challenging problems in modern astrophysics. Our own galaxy, the Milky Way, shows order and structure, as do most massive galaxies in our local neighbourhood. Yet when we look to very distant galaxies they are disordered and chaotic. One leading theory for the origin of this transformation invokes gas-rich mergers, which trigger massive starbursts leading to bulge and supermassive black hole growth. I will start by reviewing the evidence for and against this scenario. I will then turn to the interesting case of post-starburst galaxies at 0

26/11/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Cryogenic detectors for direct dark matter search
Xavier Defay (TUM)
14:00, USM, Scheinerstr. 1, Munich | ESO Garching
USM Colloquium
Talk — Reality Check: Gauging the Star-Formation Efficiency with Realistic Synthetic Observations
Christine Koepferl (MPIA Heidelberg)
09:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching

Abstract

EU ARC CASA Tutorial for ALMA Cycle 2 PIs

26-28 November 2014 at the ESO headquarters in Garching

All lectures and the advanced hands-on sessions will take place in room Telescopium (a.k.a. "Old Auditorium).

25/11/14 (Tuesday)
14:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Special MPE Talk
Talk — The XXL survey: the bright cluster sample
Florian Pacaud (AIfA, Bonn)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Particle Physics meets Astrophysics: Astrophysical counterparts of IceCube Neutrinos
Paolo Padovani (ESO)

Abstract

IceCube has recently reported the discovery of high-energy neutrinos of astrophysical origin, opening up the PeV (10^15 eV) sky. These observations are challenging to interpret on the astronomical side and have triggered a fruitful collaboration across particle and astro-physics. I will first describe the IceCube experiment and then, by using positional and energetic diagnostics, discuss plausible astronomical counterparts to the neutrino events. These include extragalactic sources, namely BL Lacertae objects, a sub-class of blazars, and Galactic pulsar wind nebulae. I will conclude by addressing the implications of the results and possible ways forward.

11:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Cosmology Seminar
Talk — A separate universe
Fabian Schmidt (MPA)
11:00, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Cosmology Seminar
Talk — Position-dependent correlation function from the SDSS-III BOSS DR10 CMASS sample
Chi-Ting Chiang (MPA)
24/11/14 (Monday)
17:15, HS2, Physik TUM Garching | ESO Garching
Muenchner Physik Kolloquium
Talk — Non-relativistic effective field theories of QCD and QED
Joan Soto (University of Barcelona)
15:30, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
MPA Institute Seminar
Talk — LIL CMB component separation
Rishi Khatri (MPA)
12:00, MPE Seminar Room 1.1.18b | ESO Garching
CAS Seminar
Talk — Observations of Core Formation: A First-Look with Perseus B1-E
Sarah Sadavoy (MPIA, Heidelberg)
09:00, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching

Abstract

ESO Garching, November 24-28, 2014                                                                                      

Recent years have seen a huge development in high-resolution astronomical techniques, which are critical to progress in many different areas of astronomy. These techniques can be divided in direct methods (Adaptive optics, lucky imaging), interferometry (including speckle imaging and spectro-astrometry), and reconstruction methods (astrotomography). This workshop aims at bringing together the different communities working on these fields and increase the synergies between them. It is indeed often necessary to combine all these techniques together in order to have a coherent and comprehensive idea of all the processes at work in a given astronomical environment.

During the workshop, experts in their fields will first introduce the major techniques described above, their use, achievements and limitations. The following sessions will be organised by science topic, with an astrophysical review of the field challenges, observational results through different techniques and technical talks describing the progress on the methods. A link to future developments in terms of instrumentation is also foreseen.

The workshop, spread over 5 days and held at the ESO headquarters in Garching, will consist of extended invited reviews, with ample time for contributing talks and discussions, and space for posters.

Conference e-mail: hires2014@eso.org

20/11/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Gamma-ray bursts as probes of the ISM and star-formation at high-z
Patricia Schady (MPE)
Download video |

Abstract

It has long been recognized that the bright and simple afterglow spectra of gamma-ray bursts (GRBs) make highly effective probes of the ISM within distant, star-forming galaxies. The imprint left by dust and gas absorption on GRB X-ray and optical afterglow spectra can be measured to a high level of accuracy, providing details on the ionisation state and location of absorbing material on sub-kpc scales. Despite significant progress in this field, there remain unresolved issues, such as the origin of the X-ray afterglow absorption 'excess', and discrepancies in the dust extinction derived from spectroscopic and photometric data. In this talk I will present results from a comprehensive study on the multi-wavelength attenuation of GRB afterglows, and highlight some of the principal outstanding issues to be addressed. A more controversial topic is the use of GRBs as probes to the cosmic star formation rate density. This area of research has received increased attention over the last few years, as more massive, dust-rich, and (super-) solar-metallicity host galaxies have come to light. I will summarise the latest developments within this field, and present ongoing work within our group to identify the relation between GRB host and other star-forming galaxy populations, and to use GRBs to study star formation at z > 2.

Video

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11:10, Library (ESO HQ, Garching) | ESO Garching
AGN Club
Talk — A refined sub-grid model for AGN in cosmological simulations: What can we learn from observations?
Lisa Bachmann (USM)
18/11/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Deeper than Hubble: the MUSE 3D view of the Hubble Deep Field South
Roland Bacon (CRAL - Observatoire de Lyon)

Abstract

I will present the results of an ultra-deep spectroscopic survey of the Hubble Deep Field South using MUSE. The data cube resulting from the 27 hours of integration covers one arcmin2 field of view at an unprecedented depth increasing the number of redshifts known in the region by an order of magnitude, up to 189 redshifts with 26 Ly-a emitting galaxies that are not even detected in the HST images down to magnitude 29.5. I will describe the overall sample properties and demonstrate the power of MUSE to perform deep field spectroscopy at comparable depth to the HST imaging deep-fields. I will discuss the promise of MUSE for future deep surveys of the Universe.

10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Spectral evolution of Hot Molecular Cores: synthetic spectra of COMs at sub-mm wavebands
Rumpa Choudhury (MPE)

Abstract

Hot Molecular Cores (HMCs) are intermediate stages of high mass star formation and also known for their rich chemical reservoirs and emission line spectra at sub-mm wavebands. Complex Organic Molecules (COMs) such as Methanol (CH3OH), Ethanol (C2H5OH), Dimethyl ether (CH3OCH3), Methyl formate (HCOOCH3) etc. produce most of these observed lines. The observed spectral feature of HMCs such as total number of emission lines, associated line intensities etc. are also found to vary with evolutionary stages. We developed various 3D models for hot cores guided by the findings of recent empirical and modeling studies of high mass star formation. We also simulated synthetic spectra of selected molecules at different evolutionary time-scales by consistently coupling the chemical evolution with radiative transfer. The spatio-temporal evolution of gaseous and grain surface abundances of these COMs due to varying physical conditions will be presented. I will show that these models reproduce the observed spectra of HMCs within the typical lifetime of hot cores. I will also discuss the advantage of using 3D models over the 1D models for estimating the physical parameters from observations. Finally, I will summarize the possible applications of these models to explore the physio-chemical evolutionary scenario during the initial stages of high-mass star formation using high resolution observations such as ALMA.

14/11/14 (Friday)
11:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — MYStIX: A new look at clustered star formation
Eric Feigelson (Penn State University)

Abstract

The formation of rich star clusters is poorly understood: Do they form quickly or slowly? Do they form as a coherent structure or by merging subclumps? How does OB stellar feedback affect the molecular environment? Progress has been slow in part due to the weakness of a stellar census in massive star forming regions inhibited by crowding, HII region nebulosity, and contamination by Galactic field stars. I describe a new project, Massive Young Star-Forming Complex Study in Infrared and X-ray that combines X-ray sources from the Chandra X-ray Observatory and infrared sources from UKIRT and Spitzer Space Telescope to produce a catalog of >30,000 young stars in massive Galactic star-forming regions at distances 0.4-4 kpc. Early empirical results based on this star sample include: diversity in star clusters morphology, dynamical relaxation, and mass segregation; clear evidence for dynamical expansion of clusters and possible evidence for subcluster merging; expected age gradients across star formation regions and unexpected age gradients within rich clusters.

13/11/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — How to catch cosmic rays and energetic protostellar winds sources by observing molecules
Cecilia Cecarelli (LAOG, Grenoble)
Download video |

Abstract

At large scales, Cosmic Rays (CR) permeate our Galaxy and ionise the UV-shielded molecular gas, which makes them crucial actors in shaping the InterStellar Medium (ISM) and governing star and planet formation. At smaller scales, newly born stars are suspected to be sources of energetic protostellar winds, which also affect the planet formation process. For example, traces of some short-lived radionucleides (e.g. 10Be) in meteoritic material suggest that the young Sun emitted an important flux of >MeV particles. These two cases, CR and energetic protostellar winds, have in common the fact that >MeV particles are impossible to directly detect, as they are scattered by the galactic magnetic fields. I will show that cold (<100K) molecules can be used to catch the sources of MeV-GeV particles and study them. Specifically, I will present observations that allowed us to infer the presence of an enhanced flux of CR and their MeV-GeV versus TeV spectrum towards molecular clouds close to some SuperNova Remnant (SNR). Using a similar technique, we revealed large fluxes of >MeV particles, similar to that necessary to explain the meteoritic 10Be presence, in a protocluster system that will eventually form a Solar-like planetary system.

Video

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12:30, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Talk — Reconnecting to Reality: 
Astronomical Analysis 
of Three Bronze Age 
Sites in Friuli
Nando Patat (ESO)

Abstract

Archaeo-astronomy is a fascinating, inter-disciplinary field of research, which mixes architecture, anthropology, archaeology, history and astronomy.  Its main aim is to investigate the astronomical knowledge of ancient cultures by studying geometric alignments to astronomically relevant directions, like the sunrise at winter solstice.
After the work done by Gerald Hawkins at Stonehenge in the seventies of last century, an army of more or less improvised archaeo-astronomers/astro-archaeologists got unleashed. Extraordinary claims were made, often not supported by archaeological evidence, confining more and more the whole discipline to a borderline region of science, often object of invasion by various esoteric currents.
This notwithstanding, serious archaeo-astronomical work has produced very interesting results. After giving an introduction to the main concepts, I will present the results of a field research I carried out in collaboration with archaeologist Susi Corazza on three Bronze Age sites in Friuli (Italy). These manufacts, dating between 1950 and 1200 B.C., are large earthworks with sides ranging between 140 and  250 meters.
Stimulated by published claims of astronomically relevant alignments and by the results obtained during recent excavations, Susi and I embarked on a surveys of the sites, which we performed by means of modern techniques.
For the details you will have to come and see the presentation. Here I can only anticipate it was great fun, it was fascinating and, above all, it allowed me to reconnect to real stuff.

12/11/14 (Wednesday)
15:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Eric Feigelson (Penn State University)

Abstract

The course Prof. Feigelson will deliver in Garching is an introductory level course, including examples and practical hands-on sessions on each of the topics covered using R, the largest public domain statistical software environment. The curriculum of the course is:  

Introduction to astrostatistics and R 
Getting started with R 
Density estimation & local regression
Fundamentals of statistical inference 
Regression
Spatial point processes 
Time series analysis 
Data mining: clustering/classification
Towards good statistical practices in astronomical studies

14:00, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching
Special Talk
Paul Jorden and Pierre Chazan (e2v Technologies)

Abstract

Recent development in the technology of silicon sensors for astronomical applications. Novel CCD and CMOS sensors have been designed for low noise and high sensitivity astronomical use. High resistivity sensors allow thicker silicon for higher red sensitivity in several types of new CCD. The capability to manufacture large sets of CCDs to form large focal planes has allowed several very large mosaics to be built for astronomy with increasing formats on the ground and in space. In addition to supplying sensors we discuss increasing capacity and interest in the commercial supply of integrated “camera” systems.

11/11/14 (Tuesday)
15:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Eric Feigelson (Penn State University)

Abstract

The course Prof. Feigelson will deliver in Garching is an introductory level course, including examples and practical hands-on sessions on each of the topics covered using R, the largest public domain statistical software environment. The curriculum of the course is:  

Introduction to astrostatistics and R 
Getting started with R 
Density estimation & local regression
Fundamentals of statistical inference 
Regression
Spatial point processes 
Time series analysis 
Data mining: clustering/classification
Towards good statistical practices in astronomical studies

12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The highest redshift quasars with Pan-STARRS1
Eduardo Banados (MPIA Heidelberg)

Abstract

High-redshift quasars provide unique information about the evolution of supermassive black holes and the intergalactic medium at early cosmic time. Numerous studies have established a sample of ~60 quasars at 5.56.5 quasars that will allow us to put constraints on the number density of massive black holes when the universe was less than 1/15 its current age. I will also discuss the implications of our search for high-redshift radio-loud quasars for the evolution of the radio-loud fraction of quasars across cosmic time.
10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — A pristine protostellar jet-disk system as observed by ALMA
Claudio Codella (Osservatorio Astrofisico di Arcetri)

Abstract

The launching of jets from protostars remains one of the most enigmatic phenomena in astrophysics. Jets are launched via a magneto-hydrodynamical (MHD) process removing excess angular momentum, and allowing accretion onto the protostar. MHD simulations of protostellar collapse argue that magnetic braking by twisted B-fields is so efficient that keplerian disks would be initially suppressed beyond 10 AU (the “magnetic braking catastrophe”). However, much larger keplerian disks (100-150 AU) have been already reported in two protostars (L1527, VLA1623), raising the acute question of their formation.

We present ALMA observations of HH212, a protostar driving a strikingly bipolar H2/SiO collimated jet. We show how ALMA-Band 7 data can trace in unprecedented detail, and within a single spectral set-up, all the crucial ingredients involved in the star-disk formation recipe, namely: (i) the dusty protostar; (ii) the axial jet launched from it; (iii) the biconical outflow cavities; (iv) the parent infalling envelope; (v) the forming keplerian disk. We reveal different kinematics among chemical tracers, and more asymmetric structures than predicted by simple models, with significant contribution from the rotating swept-up cavity. In particular, we will focus on C17O and SO emission indicating a combination of infall and rotation, with a keplerian disk nested inside.

10/11/14 (Monday)
15:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Eric Feigelson (Penn State University)

Abstract

The course Prof. Feigelson will deliver in Garching is an introductory level course, including examples and practical hands-on sessions on each of the topics covered using R, the largest public domain statistical software environment. The curriculum of the course is:  

Introduction to astrostatistics and R 
Getting started with R 
Density estimation & local regression
Fundamentals of statistical inference 
Regression
Spatial point processes 
Time series analysis 
Data mining: clustering/classification
Towards good statistical practices in astronomical studies

06/11/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Cosmology with galaxy redshift surveys
Gigi Guzzo (Osservatorio Astronomico di Brera)
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Abstract

Over the past 15 years a "standard" model of cosmology has been established. Apparently, we live in a low-density Universe with flat geometry, currently dominated by a cosmological constant driving a phase of accelerated expansion. Galaxy redshift surveys are one of the key experimental pillars that contributed to building this overall picture. Even larger surveys are ongoing or planned, with the goal of understanding the nature of cosmic acceleration, together with the origin of galaxies. In my talk I will review the most recent advances in studying large-scale structure at z~1, focusing on the results from the VIPERS project at the ESO VLT. VIPERS has curently measured around 80,000 redshifts, producing galaxy maps with unprecedented detail at 0.5

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11:10, Library (ESO HQ, Garching) | ESO Garching
AGN Club
Talk — Do AGN share the same relationships between structure and star-formation as galaxies? Insights into the co-evolutionary drivers of AGN activity from CANDELS and Herschel
David Rosario (MPE)
04/11/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Illuminating the Dark Ages: Quasars in the Epoch of Reionisation
Bram Venemans (MPIA Heidelberg)

Abstract

Quasars are the brightest (non-transient) objects observed at the highest redshifts, z>7. Such high redshift quasars are important as detailed analysis of quasar spectra provide unique information about the baryonic and physical condition of the Universe during the epoch of reionisation. Furthermore, the density of high redshift quasars puts powerful constraints on the mechanisms that are required to seed and grow >10^9 Msun supermassive black holes less than a Gyr after the Big Bang. Because these quasars are rare, surveys covering large areas on the sky are required to discover such objects. In this talk I will describe our on-going programme aimed at discovering quasars at the highest redshifts in optical and near-infrared surveys. I will present the results of our multi-wavelength follow-up observations, including mm observations with ALMA and the Plateau de Bure Interferometer of the quasar host galaxies, and discuss the implications for massive galaxy formation at high redshift.

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — The physical and temperature structure of the disk-envelope interface: ALMA DCO+ observations of VLA1623
Nadia Murillo (MPE)

Abstract

The structure of the transition from the envelope to the rotationally supported disk, the disk-envelope interface, is poorly studied. This is due to instrumental limitations and lack of disk detections in early embedded protostellar systems. To probe this region, both CO isotopologues and freeze-out tracers are needed. VLA1623A is a deeply embedded Class 0 protostar with a confirmed rotationally supported disk extending out to at least 150 AU. This makes VLA1623A an ideal target to study the disk-envelope interface. We model ALMA Cycle 0 observations of DCO+ and C18O towards VLA1623A. An analytic model using a simple chemical network coupled with radial density and temperature profiles is used as input for line radiative transfer modelling. Observations show the DCO+ emission towards VLA1623A to border the C18O emission tracing the disk. Modelling results indicate that a decrease in temperature is needed to reproduce the observed DCO+ emission, while an increase in density reproduces the C18O emission well. Our results show that the physical structure of the disk-envelope interface differs from the rest of the envelope, highlighting the drastic impact that the disk has on the envelope and temperature structure. Finally, our results show that DCO+ is an excellent temperature tracer.

09:00, Fornax (ESO HQ, Garching) | ESO Garching
Workshop — ALMA Common Software Workshop

October 2014

30/10/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Exploring Strong Gravity in the Galactic Center
Jason Dexter (MPE)
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Abstract

The Galactic center black hole, Sgr A*, provides a remarkable opportunity to study strong gravity using either orbiting stars or accreting gas. Very long baseline interferometry observations at millimeter wavelengths are now spatially resolving event horizon scales around Sgr A*, and near-infrared astrometry with the VLTI instrument GRAVITY will achieve similar resolution in the next few years. In both cases, interpreting the data requires physical modeling. I will discuss the construction of relativistic emission models from numerical simulations of black hole accretion flows and jets, what we've learned from their comparison with current data, and the prospects for detecting signatures of strong gravity (e.g., the black hole "shadow") in future observations. I will also argue that the recent discovery of a rare magnetar outburst near Sgr A* implies the presence of an unusual pulsar population in the Galactic center.

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11:10, Library (ESO HQ, Garching) | ESO Garching
AGN Club
Talk — The influence of bars on AGN fueling over the last 7 billion years
Mauricio Cisternas (IAC Tenerife, Spain)
29/10/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Particle Physics meets Astrophysics: Astrophysical counterparts of IceCube neutrinos
Elisa Resconi (1) and Paolo Padovani (2) ((1) TUM; (2) ESO)

Abstract

IceCube has recently reported the discovery of high-energy neutrinos of astrophysical origin, opening up the PeV (10^15 eV) sky. These observations are challenging to interpret on the astronomical side and have triggered a fruitful intra-cluster collaboration across particle and astro-physics. Elisa (TUM) and Paolo (ESO) will first describe the IceCube experiment and then, by using positional and energetic diagnostics, discuss plausible astronomical counterparts to the neutrino events. These include extragalactic sources, namely BL Lacertae objects, a sub-class of blazars, and Galactic pulsar wind nebulae. They will conclude by addressing the implications of our results and possible ways forward.

28/10/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Shed Light on the Properties of the Circum/Inter-galactic Gas
Fabrizio Arrigoni (MPIA Heidelberg)

Abstract

Giant (100 kpc) and luminous Lyman-alpha nebulae are observed at high redshift around high-redshift radio galaxies (HZRGs), QSOs, and in a population known as Lyman-alpha blob (LABs). There is a growing body of evidence that all of these phenomenon are somehow related, although the mechanism powering their emission is poorly understood. I will present the first results of an ongoing narrow-band imaging survey for diffuse Ly-alpha emission around z ~ 2 quasars, including the discovery of two of the largest Ly-a nebulae known, with emission extending out to ~ 500 kpc into the cosmic web. Observations of high-ionization emission lines like HeII (1640A) and CIV (1549A) provide important diagnostics of physical conditions in these nebulae, and clues to the mechanism that power them. I will present sensitive observations of these emission lines, for a giant Ly-a nebula around a quasar, as well as from deep observations of a sample of 13 Ly-alpha blobs. I will show how photoionization models can be used to interpret such observations. Future deep observations with VLT/MUSE will revolutionize the study of such nebulae, allowing the detection of multiple diagnostic lines, which will provide important constraints on the physical nature of circum/inter-galactic gas.

23/10/14 (Thursday)
16:15, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — What drives the evolution of the Milky Way's disk?
Jo Bovy

Abstract

Observations of the structure and dynamics of different stellar populations in the Milky Way's disk provide a unique perspective on disk formation, evolution, and dynamics. I will review our current knowledge of the chemo-orbital structure of the disk. I will then discuss new measurements of the kinematics and chemistry of intermediate-age stars over a large part of the Galactic disk from the APOGEE survey and the new insights these measurements provide about the formation and evolution of the disk.

12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — Discovering High-Energy Astrophysical Neutrinos with IceCube
Claudio Kopper (University of Alberta)
22/10/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Prospects in Hadron Spectroscopy
Vincent Mathieu (Indiana University, USA)

Abstract

There are several experiments in Europe (COMPASS, LHCb), USA (CLAS, GlueX) and Asia (BES, Belle) devoted to hadron spectroscopy. In this talk, their goals and prospects are presented with a special emphasis on the discovery of new 'exotic' resonances. There are indeed indications from these experiments about resonances (hybrid mesons, glueballs, tetraquarks, etc.) beyond the quark model classification. However, a close collaboration between theorists and experimentalists is necessary to draw robust conclusions about their existence. Vincent will review the theoretical developments necessary to fully exploit the data provided by the experiments and finally reach their objectives.

21/10/14 (Tuesday)
12:30, Room 231 (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Brightest Cluster Galaxies as probes of galaxy formation
Paola Oliva (Swinburne University, Australia)

Abstract

Brightest group and cluster galaxies (BGGs/BCGs) are old giant ellipticals, which have been shown to be different from any other cluster galaxy. Despite of being easy detectable their formation and evolution is still poorly understood. I will present a statistical analysis of a large sample of 883 Brightest group and cluster galaxies (BGGs/BCGs) from the Galaxy and Mass Assembly Survey (GAMA). We analyse their stellar mass growth, position in the cluster, and the percentage of BGGs/BCGs that show H\alpha in emission. We find that BCGs grow steeply until z~0.5, and slow down at lower redshift.

BCGs have been predicted to have a more active accretion history than less massive galaxies. We further use IFU spectroscopy to study the spatially-resolved stellar populations of BCGs and their connection with galaxy’s angular momentum. We find that all the BCGs in our sample have gone through at least one major merger after z=1. Our stellar population analysis suggest that BCGs have a more active accretion history than early-type galaxies of similar mass.

16/10/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The importance of radio-AGN feedback in massive galaxy formation: Insights from the COSMOS survey
Vernesa Smolcic (University of Zagreb)
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Abstract

Radio outflows of active galactic nuclei (AGN) are invoked in cosmological models as a key feedback mechanism in the latest phases of massive galaxy formation. However, from an observational point of view, the impact of such a mechanism on galaxy formation and evolution is still poorly understood. I will present our results, based on radio-selected samples at low (SDSS/NVSS and 3CRR surveys; z<0.3) and high redshifts (COSMOS survey, z<3), that for the first time observationally test the importance of radio-mode feedback in massive galaxy formation (out to z~3). In particular, in the context of the commonly adopted blue-to-red galaxy evolution scenario we find that the two major radio AGN populations -- the powerful high-excitation, and the weak low-excitation radio AGN -- represent two, earlier and later, stages of massive galaxy build-up. To expand this study to higher redshifts, we developed a new method that efficiently selects weak AGN (such as Seyfert, LINER, and absorption line AGN) based only on their NUV-NIR photometry. This method allowed us to study, for the first time, the cosmic evolution of weak radio AGN out to z~3, which can directly be linked to the radio-mode feedback prediction in cosmological models.

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14/10/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The origin of free-floating planets and brown dwarfs
Viki Joergens (MPIA Heidelberg)

Abstract

Free-floating substellar objects are the link between stars and planets. They play a key role for our understanding of star and planet formation and of cool planetary-like atmospheres. After reviewing aspects of their physics, detection history, and formation, I will present observations of young brown dwarfs and free-floating planets. This includes a precise radial velocity survey for companions at the VLT, Herschel studies of disks, accretion studies, and spectro-astrometric detections of outflows. I will present our recent result that the coolest known object that is formed in a star-like mode is a free-floating planet. We discovered significant accretion (VLT/SINFONI) and a substantial disk (Herschel) of the young 12 Jupiter mass object OTS44 (M9.5). This demonstrates that the processes that characterize the canonical star-like mode of formation apply to isolated objects down to a few Jupiter masses. Our results suggest that the increasing number of young free-floating planets and ultra-cool field T and Y dwarfs are the low-mass extension of the stellar population.

11:30, MIAPP Building | ESO Garching
Cluster Universe Colloquium
Talk — Neutrinos and the Standard Model
Samuel M. Bilenky (Joint Inst. for Nuclear Research, Dubna, Russia)

Abstract

In the first part of the talk the basics of neutrino masses and mixing and the phenomenological status of neutrino oscillations will be discussed . In the second part the special role of neutrinos in the Standard Model and the most economical possibility for neutrinos to be massive and mixed will be considered.

13/10/14 (Monday)
09:00, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching

Abstract

The study of stellar populations is one of the most relevant diagnostics to constrain galaxy formation and evolution. Quantitative analyses of the stellar content of stellar systems pave the way to `convert'  starlight into physical quantities like stellar masses, chemical abundances and star formation rates, and to trace back in time the evolution and the chemical enrichment history of galaxies.


The main goal of this workshop is to share observations, models, techniques and recent results. Detailed discussions on the methods will favor new and tighter exchanges of ideas concerning our view of galaxy evolution. Particular emphasis will be given to the current limitations affecting the intrinsic degeneracy of the multi-dimensional parameter space (age and metallicity distributions, IMF, kinematics, reddening law, dust), and to the possible solutions to build a more unified and coherent picture of galaxy evolution.


During the workshop together with the current state of the art we will also discuss the impact that E-ELT and its first generation of instruments will have on resolved and unresolved stellar populations.

10/10/14 (Friday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Babak Tafreshi (TWAN)

Abstract

It is an amazing experience to be under an ideal night sky, a pure natural beauty unspoiled by urban lights, where you look all around the horizon and find no prominent sign of city lights, neither direct lights or light domes. There are not many locations left on this planet where you can still experience a dark sky like this. During the spring of 2014, a team of ESO photographers (H. Zodet, Y. Beletsky, C. Malin and B. Tafreshi) embarked on a pioneering expedition to capture the stunning night sky of the Chilean Atacama Desert using state-of- the-art Ultra High Definition technology. We traveled to several observatories to record high resolution images, time-lapse motions, and full dome content for planetariums. The images display where observational astronomy happens at its cutting edge, they also illustrate principles of practical astronomy and stargazing and support science communicators. They also display the natural colors and appearance of the night sky. One of the challenges was to deliver eye-catching images while avoiding montage or over-cooked processing. Watch out for the adventurous stories behind some of these images and their technical aspects!

09/10/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Fundamental Physics and Astrophysics Problems Around the Birth and Death of Neutron Stars
Thomas Janka (Max-Planck-Institut für Astrophysik)
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Abstract

The birth of neutron stars in supernova explosions and their death in violent binary mergers are catastrophic events, which are connected to important open questions of stellar astrophysics. They also offer possibilities to probe regimes of extreme physics that are hardly accessible by laboratory experiments and direct observations. Numerical simulations are therefore indispensable to make progress in understanding the processes in the obscured deep interior of these explosive phenomena. This talk will review recent progress in a fast-moving field from a theorist's perspective. 3D supernova simulations have become possible only very recently and have already led to the discovery of new and unexpected effects, but still need to confirm basic theoretical concepts of the explosion mechanism. Nevertheless, based on these concepts models are now able to predict explosion properties and asymmetries, the mass and metallicity dependent progenitor-explosion-remnant connection, birth masses, kicks and spins of the compact remnants, and crucial parameters that determine supernova nucleosynthesis. However, the best models cannot support supernovae as the long-sought cosmic site of the production of trans-iron elements including lanthanides and actinides by the rapid neutron-capture process. Instead, relativistic 3D simulations have confirmed considerable ejection of very neutron-rich matter in neutron-star mergers and thus demonstrate the potential of such events as main sources of r-process elements in the universe. The unambiguous detection of a characteristic, radioactively powered electromagnetic transient, possibly in connection with a short gamma-ray burst, is a promising perspective for a final proof of this theoretical prediction. On the other hand, the detection of gravitational waves from neutron-star mergers with upcoming laser interferometers like Advanced LIGO and VIRGO can yield accurate measurements of neutron-star radii and will thus provide tight constraints of the still uncertain properties of ultradense matter in neutron stars.

Video

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11:10, Library (ESO HQ, Garching) | ESO Garching
AGN Club
Talk — Detailed Shape and Evolutionary Behavior of the X-ray Luminosity Function of AGNs
Takamitsu Miyaji (UNAM Ensenada (Mexico))
08/10/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Fatal fate: A gas cloud on its way to the massive black hole in the Galactic Center
Stefan Gillessen (MPE)

Abstract

The Galactic Center is a unique astrophysical laboratory. Due to its proximity, we can observe in unparalleled detail the interaction of the massive black hole with its stellar and gaseous environment. In 2011, we discovered a compact gas cloud (”G2”) with roughly 3 Earth masses that is falling on a near-radial orbit toward the massive black hole, with a pericenter passage in 2014. Our 10-year data set beautifully shows that G2 gets tidally sheared apart due to the massive black hole’s force. We expect that in addition to the tidal effects, hydrodynamics will get important in the coming years, as G2 collides with the hot ambient gas around Sgr A*. Simulations show that ultimately, the cloud’s material will fall into the massive black hole. Predictions for the accretion rate and luminosity evolution, however, are very difficult due to the many unknowns. Nevertheless, this might be a unique opportunity in the next years to observe how gas feeds a massive black hole in a galactic nucleus.

07/10/14 (Tuesday)
10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Accretion and stellar magnetism in T Tauri stars
Gaitee Hussain (ESO)

Abstract

Magnetic field maps of about a dozen accreting T Tauri stars have now been obtained using the technique of Zeeman Doppler imaging. I will give an overview of what we've learnt about the magnetic fields on these stars and a possible relationship between accretion, rotation and the large scale magnetic fields in classical T Tauri stars. I will then present results from a new study focussing on the wTTS, Lkca 4, which suggests the picture of stellar magnetism might fundamentally change in stars that are no longer accreting.

02/10/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Recombination and Relativistic Effects in Shock Breakouts and Cooling Envelopes: Supernovae and Low Luminosity Gamma Ray Bursts
Re'em Sari (Racah Institute of Physics, the Hebrew University, Jerusalem)

Abstract

Stellar explosions in Supernovae or Gamma Ray Bursts begin with the launching of a shock into the stellar envelope. As the shock wave propagates towards the edge of the star, the decreasing density causes the shock to accelerate, and eventually break out of the star. We show that for fast shocks, with v>10,000km/s, the radiation is out of equilibrium causing the breakout to appear in x-rays rather than the previously estimated UV. Later, recombination in the cooling expanding envelope may lead to the flat lightcurve of type-IIp supernovae. Finally, we argue, that relativistic effects in extreme breakouts may be the sources of low luminosity Gamma Ray Bursts, and show that their properties match well with our theory.

14:00, Fornax (ESO HQ, Garching) | ESO Garching
Workshop — SPHERE Mini-Workshop

Abstract

SPHERE is the extreme adaptive optics system and coronagraphic facility at the VLT. Its primary science goal is imaging, low-resolution spectroscopic, and polarimetric characterization of extra-solar planetary systems at optical and near-infrared wavelengths. SPHERE has completed 3 commissioning runs in May, July, and August 2014 (the 4th run is in October), and has been offered to the community for P95. To present SPHERE to the local community, prepare for the science verification (end of 2014), P95 phase 2, and future proposals, a one-day workshop will be held at the ESO Vitacura offices in Santiago on October 2nd, 2014.  

Speakers from the SPHERE consortium and ESO will be:
Jean-Luc Beuzit and David Mouillet, IPAG
Markus Feldt, MPIA
Kjetil Dohlen, LAM
Markus Kasper, ESO Garching
Zahed Wahhaj, Julien Girard, Dimitri Mawet, ESO Santiago

September 2014

30/09/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Modelling Galaxies within state-of-the-art Cosmological Simulations
Violeta Gonzalez-Perez (University of Durham)

Abstract

Galaxies are thought to form within haloes of dark matter, whose gravity allows the galaxies to exist. The formation and evolution of galaxies is affected by a multitude of other processes besides gravity and computational modelling is the only way we can attempt to understand all these processes. In this work we present a new development of the GALFORM semi-analytical model of galaxy formation and evolution, which exploits a Millennium Simulation-class N-body run performed with the Wilkinson Microwave Anisotropy Probe 7 cosmology. We use this new model to study the impact of the choice of stellar population synthesis (SPS) model on the predicted evolution of the galaxy luminosity function. Besides this model, we have generated a new GALFORM flavour constructed from merger trees derived from EAGLE, a hydrodynamical simulation. We compare results from both GALFORM and EAGLE.

25/09/14 (Thursday)
13:00, Fornax (ESO HQ, Garching) | ESO Garching
Optical Metrology Talks
H. Schwenke (Etalon AG)

Abstract

The Absolute Multiline Technology is a pioneering solution to the precision measurement of lengths up to 20 m with a measurement uncertainty of 0.5 µm per meter, on up to 100 channels simultaneously. Unlike conventional interferometers, the laser beam of the Absolute Multiline Technology can be interrupted at any time without causing precision loss. In fractions of a second the absolute distance is recovered.

11:10, Library (ESO HQ, Garching) | ESO Garching
AGN Club
Talk — Chandra Survey in the AKARI North Ecliptic Pole Field: Search for Compton-thick AGN
Mirko Krumpe (MPE)
23/09/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — AKARI FIR All-Sky Maps
Yasuo Doi (University of Tokyo)

Abstract

We present the AKARI far-infred (FIR) all-sky maps and describe its characteristics, calibration accuracy and scientific capabilities. The AKARI FIR survey has covered 97% of the whole sky in four photometric bands, which cover continuously 50--180 micron with band central wavelengths of 65, 90, 140, and 160 microns. The spatial resolution of the maps is ~60--90 arcsecs and the detection limit is ~1--12 [MJy/sr] with an absolute accuracy of ~20%.

The data for the first time reveal the whole sky distribution of interstellar matter with arcminute-scale spatial resolutions at the peak of dust continuum emission, enabling us to investigate large-scale distribution of interstellar medium in great detail. The filamentary structure covering the whole sky is well traced by the all-sky maps.

The data are currently under assessment by the AKARI science team members and to be publicly released later this year. The release schedule is also described in this presentation.

10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Galactic Cold Interstellar Filaments
Ke Wang (ESO)

Abstract

The molecular ISM is known to be highly hierarchical and filamentary. Studies in recent years have demonstrated the importance of filaments in star formation, at scales of <10 pc and >100 pc, and suggest a new paradigm for star formation. However, extremely filamentary giant molecular clouds (GMCs) at scales between 10 and 100 pc have not been studied systematically. A compelling sample does not exist at the first place, due to a historical limitation in the identifying methodology (i.e., extinction).
We recently launched a dedicated project to bypass this limitation, using the full Hi-GAL images to directly search for large filaments in the entire Galactic plane. As a pilot study of the project, we select a sample of 9 most prominent filaments with a length of 30-103 pc and mass (2.4-19)x10^4 Msun. These filaments are cold compared to surroundings and show no significant internal heating. This makes our project unique in probing the early evolutionary phases to study the connection of filamentary GMCs to the onset of star formation. I will present preliminary analysis of the pilot sample.

18/09/14 (Thursday)
12:30, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Sandra Savaglio (U. Calabria)

Abstract

The Cosmic Microwave Background (CMB) radiation is one of the most important discoveries ever made in the history of mankind. Originating from an early phase of the evolution of the Universe, its existence was predicted in 1948, but discovered only many years later, serendipitously, by two physicists working on a telecommunication radio antenna. The most striking feature of the CMB is its uniformity in all directions in the sky. Its very weak deviation from uniformity is only seen in images taken with very sophisticated instruments and satellites. Present cosmology is concentrated on unveiling the details related to the origin of the universe. Latest discovery on CMB (from BICEP2 in March 2014) is the indirect detection of gravitational waves originating soon after the Big Bang. If confirmed, this will be the first clear evidence that the theory of Inflation is correct. Stay tuned to learn more, the scientific community is awaiting the results of a new independent analysis of the signal from the Planck mission later this year.

16/09/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Astrochemistry, cosmic rays, and H3+
Miwa Goto (USM)

Abstract

The talk starts with the introductory accounts of the astrochemistry, the cosmic rays and the hydrogen molecular ion H3+ to illustrate how the study of the one has immediate impacts on the other two. The Galactic Center is used as a laboratory to show that the three elements lively influence each other. The emphasis is put on how the spectroscopy of the H3+ has been used to develop our view of the interstellar medium in the Galactic Center in the past decade.

15/09/14 (Monday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Oxygen in the Local Universe: Error and Uncertainty in Abundances
Kevin Croxall (Ohio State University)

Abstract

The metal content of a galaxy is one of the most important properties used to distinguish between viable evolutionary scenarios and strongly influences many of the physical processes in the ISM. An absolute and robust calibration of extragalactic metallicities is essential in constraining models of chemical enrichment, chemical evolution, and the cycle of baryons in the cosmos. Despite this strong dependence on abundance, the calibration of nebular abundances from nebular emission lines remains uncertain. Different calibrations of the abundance scale require different assumptions, which may or may not be valid, and measurements, not all of which are easily obtained. MODS on LBT and the late Herschel Space Observatory are allowing us to clarify this long standing calibration uncertainty. The sensitivity of MODS is enabling the detection of numerous temperature sensitive lines and features in nearby galaxies and Herschel observations of the [O III] 88 micron fine structure line in nearby galaxies are enabling the determination of nebular abundances that are nearly independent of temperature. I will discuss current efforts at constraining the abundance scale using these modern facilities.

11/09/14 (Thursday)
11:10, Library (ESO HQ, Garching) | ESO Garching
AGN Club
Talk — The host galaxies of Narrow-Line Seyfert 1 AGN
Julia Scharwächter (Observatoire de Paris, LERMA)
09/09/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Interstellar medium and initial stages of star formation: comparing simulations and observations
Johanna Malinen (University of Helsinki)

Abstract

Filamentary structures in interstellar molecular clouds have long been recognised as an important part of the star formation process. Recent studies have confirmed that dense cores in different stages of star formation are commonly located in the filaments. Therefore, it is important to study the structure and formation of the filaments and the cores, to understand the details of the early phases of star formation. The density structure of molecular clouds can be studied using many different methods and wavelengths. All techniques have their own drawbacks, and, therefore, it is crucial to compare the results obtained with different methods. Before making conclusions on observational data, the observational uncertainties and biases should be evaluated with simulations. In this presentation, I will give a short overview of star formation theory, observations, and simulations, and review the main results of my PhD thesis, concentrated on comparing simulations and observations of the early, prestellar phase of star formation.

10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Interstellar chemistry of nitrogen hydrides with Herschel
Romane Le Gal (IPAG, Grenoble)

Abstract

Nitrogen is amongst the most abundant metals in the interstellar medium. Observations of several nitrogen-bearing species suggest abundances in sharp disagreement with current chemical models. Although some of these observations show that some gas-grain processes are at work, gas-phase chemistry needs first to be revisited. Strong constraints are provided by recent Herschel/HIFI observations of nitrogen hydrides fundamental rotational transitions in cold gas [1]. The aim of my PhD thesis work was to comprehensively analyse the interstellar chemistry of nitrogen, focussing on the gas-phase formation of the simplest polyatomic species, namely nitrogen hydrides. In cold and dense gas conditions, the chemistry of these latter is initiated by slow neutral-neutral reactions (the conversion from N to N2, in contrast to their carbonated and oxygenated analogues. We have investigated and revisited this specific part of the nitrogen chemistry. To this purpose, we present a new chemical network [2] in which the kinetic rates of critical reactions involved in nitrogen chemistry have been updated. Our new network is based on recent experimental and theoretical studies, including the calculation of nuclear spin branching ratios [3]. The different spin symmetries of the nitrogen hydrides are treated self-consistently, together with the ortho and para forms of molecular hydrogen. This new network is used to model the time evolution of the nitrogen species abundances in cold and dense gas conditions (n=10^4 cm^-3, T=10 K). The steady-state results are compared to observations of NH, NH2 and NH3 towards a sample of low-mass protostars, with a special emphasis on the influence of the overall amounts of gaseous carbon, oxygen, and sulphur. Our predicted ortho-to-para ratios for NH2 and NH3 [4] are also compared with the observational results of Persson et al. towards cold diffuse clouds [5].

References
[1] Hily-Blant, P., Maret, S., Bacmann, A., et al. 2010a, A&A, 521, L52
[2] Le Gal, R., Hily-Blant, P., Faure, A., Pineau des Forêts, G., Rist, C., & Maret, S., 2014, A&A, 562, A83
[3] Rist, C., Faure, A., Hily-Blant, P., & Le Gal, R., 2013, J. Phys. Chem. A, 117, 9800
[4] Faure, A., Hily-Blant, P., Le Gal, R., Rist, C., & Pineau des Forêts, G., 2013, ApJ, 770, L2
[5] Persson, C. M., De Luca, M., Mookerjea, B., et al. 2012, A&A, 543, A145

03/09/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — New experimental results for the charged-pion polarisability from COMPASS
Alexey Guskov (CERN)

Abstract

Alexey will report on new results for the charged-pion polarisability from the COMPASS experiment at CERN.

02/09/14 (Tuesday)
10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Physical characterization of brown dwarfs
Elena Manjavacas (MPIA Heidelberg)

Abstract

Brown dwarfs are substellar objects (M<75MJup) which do are not able to sustain H burning. During their evolution, they cool down, changing their effective temperature and their spectral types, and it is difficult to constrain masses and ages for brown dwarfs. Determining the initial mass function and the evolution for these substellar objects is therefore a challenging problem. During my PhD I addressed the problem of brown dwarf characterization in three different approaches: determining parallaxes of several T brown dwarfs, medium resolution VLT/ISAAC spectroscopy of young M-L brown dwarfs and searching for brown dwarf binaries using VLT/X-Shooter spectroscopy.

August 2014

26/08/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Rosetta: the European Space Agency's comet-chasing mission
Mark McCaughrean (ESA)

Abstract

On 6 August, Rosetta successfully rendezvoused with Comet 67P/Churyumov-Gerasimenko at a distance of more than 400 million km from Earth, marking the beginning of its main science mission. For the first time, Rosetta will escort and study a comet in great detail and at close proximity as it evolves from now until perihelion in August 2015 and beyond, and will deploy a smaller lander, Philae, to the comet's surface in November this year.

I'll give an overview of the scientific goals of this unique mission, the journey taken to reach 67P/C-G, and what to expect over the coming months as the landing site is selected and Philae is deployed. I'll also give a flavour of the early science results from the mission. Finally, I'll discuss some of the successes and pitfalls of our substantial communications and outreach campaign for the mission.

25/08/14 (Monday)
14:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy Communication Seminar
Talk — Communicating Solar Astronomy
Kentaro Yaji (NAOJ, Solar Observatory)

Abstract

The Sun is the nearest star to us, so the public is greatly interested in the Sun itself and in solar activity. At NAOJ, the Solar Observatory and the Hinode Science Center are the solar research divisions. They release solar observation data and science results not only to researchers, but also to the public. The speaker will talk about the public relations and outreach activities of these divisions.

14:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy Communication Seminar
Talk — Connecting the invisible to the public: public relations for the NAOJ’s radio astronomy projects
Masaaki Hiramatsu (NAOJ, Chile Observatory)

Abstract

NAOJ operates several radio telescopes such as ALMA, the Nobeyama 45-metre and VERA. In this talk the speaker will introduce the public relations activities and strategy behind the radio astronomy projects at NAOJ.

14:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy Communication Seminar
Talk — Public Outreach at the Subaru telescope
Saeko Hayashi (NAOJ, Subaru Telescope)

Abstract

The Subaru Telescope is an 8.2-metre optical infrared telescope atop Mauna Kea, Hawaii, operated by NAOJ. In this talk, we summarise our public information activities. In addition to sharing information about the discoveries made with the Subaru Telescope and various operational activities, we offer informative tours and deliver information through on-site or remote presentations. All these public information and outreach activities are to ensure not just short-term visibility for the telescope but also long-term support from the citizens of Japan and the local community where the telescope is located.

19/08/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The probability density function in molecular gas
Maria Cunningham (UNSW, Sydney)

Abstract

We have undertaken multi-molecular-line surveys of the G333 and Vela C molecular clouds, using the wide-band capabilities of the Mopra telescope. The data sets are being used to investigate the chemistry, kinematics and hierarchical structure of the interstellar medium. In this talk we discuss the probability density function distribution in a range of molecules tracing different critical densities. We show that the chemical and excitation differences between different molecules show up as differences in the PDF for each molecule. The interpretation of the differences in terms of the type of gas traced by different molecules, and how useful each is for tracing gravitationally bound gas and/or gas that is tracing the broader hierarchical structure is discussed.

14/08/14 (Thursday)
12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — Large-scale structures in bimetric gravity
Malin Renneby (Chalmers University of Technology, Sweden)

Abstract

One of the most prominent questions in modern cosmology is the origin of the accelerated expansion of the universe. A solution might lie in modifying gravity in the infrared by adding a small mass to its mediating particle. In recent years, massive gravity and its dynamical extension bimetric gravity have been shown to be classically consistent theories. This prompts for a phenomenological investigation of their predictions in cases already examined in general relativity, such as in spherically-symmetric geometries and on cosmological scales. In this talk, Malin will focus on aspects related to the evolution of large-scale structures through analysis of the bimetric equations of motion for linear perturbations.

12/08/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — What can narrow-line regions tell us about AGN and their host galaxies?
Julia Scharwächter (Observatoire de Paris, LERMA)

Abstract

The ionizing continuum emitted by AGN can photoionize gas in the host galaxies on scales of tens of parsecs to kiloparsecs. The AGN-ionized gas on these scales is called 'narrow-line region' (NLR), because the gas emission lines are narrow (typically ~200-500 km/s) compared to the lines emitted by the high-density, high-velocity 'broad-line' gas at ~0.1 pc from the AGN. Since the density in the NLR is sufficiently low, the spectrum shows prominent forbidden lines ranging from low to high ionization. Emission from the NLR can be used to probe the shape of the AGN ionizing continuum, gas conditions in the AGN environment, obscuration and AGN unification, as well as AGN feedback. I will give an overview of the picture that has emerged from observations of AGN NLRs. I will show recent results from our ongoing optical IFU studies of NLRs in Seyfert galaxies and discuss open questions.

July 2014

29/07/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — The dust budget crisis in high-redshift submillimetre galaxies
Kate Rowlands (University of St. Andrews)

Abstract

Dust emission is a sensitive probe of the ISM in galaxies. Previous surveys have found galaxies were significantly dustier at earlier times, but the cause of this evolution, and the origin of the dust, are hotly debated topics in astrophysics. Using panchromatic data from the UV to the submillimetre, I will explore the physical properties and SEDs of a sample of ~250μm rest-frame selected submillimetre galaxies (SMGs). I then compare the SMGs to dusty galaxies at low redshift selected from one of the largest extragalactic Herschel surveys, H-ATLAS. From SED analysis it is found that a large fraction of the dust luminosity in SMGs originates from star-forming regions, whereas at lower redshifts the dust luminosity is dominated by the diffuse ISM. At the same dust mass the SMGs are offset towards a higher star-formation rate compared to the low redshift H-ATLAS galaxies. This is not only due to the higher gas fraction in SMGs but also because they are undergoing a more efficient mode of star formation. I will also present the results of chemical evolution modelling to understand the origin of dust in SMGs. Even after accounting for dust produced by low mass stars and supernovae the deficit in the dust mass budget provides support to the hypothesis that higher supernova yields, and/or substantial grain growth in the interstellar medium are required in order for the predicted dust mass to match observations of SMGs.

22/07/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Orion as a paradigm for star formation
Nicola Da Rio (University of Florida)

Abstract

Young stellar clusters and associations are the direct output of the star formation process, and therefore can provide useful clues on how the conversion of gas into stars takes place in space and time, and on several details of the physics involved. The Orion Nebula Cluster, the densest cluster within a large star forming complex, due to its vicinity and abundant young population has always been target of observational studies. I will describe my research on this region, focusing on the first accurate constraint of its age spread - which therefore tracks the duration of star formation - the substellar IMF, the accretion lifetimes, the structure and kinematics. In particular I will describe the first conclusive evidence that the system is expanding due to early gas removal.

15/07/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — X-shooter and SINFONI reveal powerful outflows in X-ray luminous obscured QSOs
Marcella Brusa (University of Bologna)

Abstract

Quasar feedback on host galaxies in the form of powerful outflows is invoked as a key mechanism to quench star formation in massive galaxies, but direct observational evidences are still scarce and the debate on the physical origin of the observed outflows is still open. After reviewing the observational constraints we have so far on the existence and origin of this mechanism, I will present new X-shooter@VLT observations of a representative sample of 10 luminous, X-ray obscured QSOs at z~1.5 from the XMM-COSMOS survey, expected to be caught in the transitioning phase from starburst to AGN dominated systems. From the rest-frame optical spectra we could infer the presence of outflows in 6 out of 8 sources. This may be considered as a compelling indication that the color selection applied to our X-ray sample is effective in picking up objects in the outflowing phase. A comparison of the outflow energetic with the AGN luminosity and the kinetic energy associated to stellar processes, suggest that the AGN rather than the on-going star-formation may be the major driver for the presence of the observed broad and shifted components. In the two brightest sources we were also able to probe, via slit resolved spectroscopy, that the outflows extend up to 10 kpc scales. Most important, thanks to SINFONI data available for one of these 2 targets (XID2028) we were able to probe the presence of both negative and positive outflow-induced feedback in the host galaxy of the powerful QSO.

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — The dependence of star formation efficiency on gas density
Andreas Burkert (LMU)

Abstract

Observations indicate that the efficiency of star formation is a strong function of gas density or gas surface density with the star formation efficiency approaching unity on the scales of molecular cloud cores. I will argue that these observations are very puzzling. They require that dense gas has to be replenished on timescales that are similar to local gravitational collapse and star formation timescale. Numerical simulations cannot reproduce these observations, indicating that some fundamental processes that regulate star formation are still very poorly understood.

14/07/14 (Monday)
09:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching

Abstract

This ESO workshop, which will be the first ever workshop dedicated to AGN clustering, aims to summarise our current understanding of AGN clustering and how the community should prepare for upcoming data sets and challenges.

10/07/14 (Thursday)
15:00, MPE Old Seminar Room (MPE, Garching) | ESO Garching
Cluster Universe Colloquium
Talk — Quasar feedback in the form of powerful outflows: recent results and perspectives
Marcella Brusa (University of Bologna)

Abstract

Quasar feedback on host galaxies in the form of powerful outflows is invoked as a key mechanism to quench star formation in massive galaxies, but direct observational evidences are still scarce and the debate on the physical origin of the observed outflows is still open. In this talk Marcella will review the observational constraints on the existence and origin of this mechanism, and present new X-shooter@VLT observations of a representative sample of 10 luminous, X-ray obscured QSOs at z~1.5 from the XMM-COSMOS survey, expected to be caught in the transitioning phase from starburst to AGN dominated systems. From the rest-frame optical spectra we could infer the presence of outflows in 6 out of 8 sources. This may be considered as a compelling indication that the color selection applied to our X-ray sample is effective in picking up objects in the outflowing phase. A comparison of the outflow energetic with the AGN luminosity and the kinetic energy associated to stellar processes, suggest that the AGN rather than the on-going star-formation may be the major driver for the presence of the observed broad and shifted components. In the two brightest sources we were also able to probe, via slit resolved spectroscopy, that the outflows extend up to 10 kpc scales. Most important, thanks to SINFONI data available for one of these 2 targets (XID2028) we were able to probe the presence of both positive and negative outflow-induced feedback in the host galaxy of the powerful QSO. Further perspective of studies with spatially resolved NIR spectroscopy and in the millimiter bands (e.g. ALMA, IRAM) to assess definitely the energetics of the outflows will also be discussed.

09/07/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — The motion of dark matter in phase space and indirect detection signals
Francesc Ferrer (University of Washington)

Abstract

If dark matter (DM) has long-range interactions, the annihilation rate depends not only on the density profile, but also on its velocity distribution. Using phase-space considerations, we will discuss how the expectations for the indirect detection of DM in models with Sommerfeld enhancement can differ significantly from the standard estimate. In addition, the DM at the center of the Galaxy will be redistributed by the presence of the super-massive black hole. We will take a closer look at the DM profile in the vicinity of a black hole using a relativistic analysis, and discuss its implication for indirect searches of DM and tests of the black hole no-hair theorems.

03/07/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Atomic and molecular gas properties of galaxies: constraints on galaxy formation models
Guinevere Kauffmann (MPA)
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Abstract

Galaxies form when gas is able to cool, condense and form stars within dark matter halos. Over the past 5 years, there have been a number of efforts aimed at linking the atomic and molecular gas properties of nearby galaxies to their stellar properties in a systematic way. This talk will describe the main results obtained by recent surveys carried out using the Arecibo, IRAM and Westerbork radio telescopes, and what we have learned about the late stages of galaxy formation as a result.

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12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — Seeing the Universe through lensing
Stefan Hilbert (LMU/MPA)

Abstract

Gravitational lensing is the name astronomers give to the deflection of light from distant sources by the gravity of intervening matter structures, which can be stars, galaxies, or the whole large-scale structure. Stefan will give a brief introduction to strong and weak gravitational lensing, and how astronomers may use it to learn more about the matter and energy content of our Universe. He will discuss advantages of lensing, but also address some obstacles to overcome on the way to precision cosmology.

02/07/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Recent and Future Results from Lattice QCD
Andreas Kronfeld (Fermilab)

Abstract

In this talk, Andreas will report on recent results from lattice QCD of broader interest. Most of these pertain to mesons and are useful for interpreting quark-flavor experiments. These highlight the recent progress well, and provide a basis for nucleon calculations of comparable quality. He will discuss how these calculations are becoming important in dark matter searches and neutrino scattering.

01/07/14 (Tuesday)
10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Protoplanetary disks masses from CO isotopologues line emission
Anna Miotello (MPE)

Abstract

An accurate measurement of disk masses is a key point for the understanding of disks evolution all the way up to planet formation. The disk mass is indeed the initial reservoir of material made available to build planets. So far, virtually all disk mass determinations are based on millimeter continuum observations of large dust grains. To derive the total gas + dust disk mass from these data involves however some assumptions on the dust opacity and the gas-to-dust ratio, usually taken to be 100 being gas the main disk constituent.

The alternative method for deriving disk masses relies on direct observations of the gas, whose bulk mass is in the outer cold (T~30K) regions. This zone can be well traced by sub-mm lines of CO. However, 12CO is not a good mass tracer because its lines become optically thick at the disk surface. Less abundant CO isotopologues such as 13CO, C18O and C17O have optically thin lines and as a consequence probe the gas down to the midplane. The total gas mass is then obtained with the isotopologue ratios taken to be constant at the isotope values found in the local ISM. This approach is however imprecise, because isotope selective processes are ignored and more detailed analysis should be carried out.

We properly treat the isotope-selective photodissociation, the main process controlling the abundances of CO isotopologues, for the first time in a full disk model (DALI, Bruderer et al. 2012). The chemistry, thermal balance, line and continuum radiative transfer are all considered together with a chemical network that treats 13CO, C18O, C17O, isotopes of all included atoms, and species, as independent species. Our results show that considering isotopologues ratios as constants leads to overestimate disk masses by up to one order of magnitude. Isotope selective processes indeed lead to regions where the isotopologues abundance ratio e.g. of C18O/12CO is considerably different from the atomic 18C/12C ratio.

The focus of our work is on the emission of the various isotopologues and their dependence on stellar and disk parameters, to set the framework for the analysis of ALMA data. We will employ ALMA to its full potential, only if we will have the correct tools to analyze its data.

June 2014

26/06/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Regulation of Star Formation in the Molecular Gas Disks of Spiral Galaxies
Eva Schinnerer (MPIA Heidelberg)
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Abstract

Understanding the processes that regulate the formation of stars within galaxies is one of the major themes in current astrophysical research. Giant Molecular Clouds (GMCs, size ~ 40pc) are thought to play a critical role in these processes as they host most of the massive star formation occurring in our Galaxy. Detailed observations on their scales can provide important insights on the properties of the star forming interstellar medium and the conditions promoting the formation of massive stars. Combining exquisite data on the molecular gas disk in the grand-design spiral galaxy M51 at 40pc resolution from the PdBI Arcsecond Whirlpool Survey (PAWS) with ancillary data across the electromagnetic spectrum allowed us to investigate in detail how molecular gas, dust and star formation relate across the galaxy disk and test common assumption about Giant Molecular Clouds. I will present highlights from our studies.

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25/06/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Accreting Magnetars
Wei Wang (Nat. Astron. Observatory, China)
24/06/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The SkyMapper Telescope and Survey
Christian Wolf (RSAA, Mt Stromlo Observatory, Australian National University )

Abstract

After a lengthy commissioning period, the SkyMapper telescope at Siding Springs Observatory in Australia has finally started its eponymous survey in March 2014. I will present the updated survey plans including its various components, an outlook to the science pursued including first results and the anticipated timeline for finishing the survey and worldwide access to the data.
23/06/14 (Monday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Measuring Ho and Weighing Supermassive Black Holes with H2O Megamasers
Jim Braatz (NRAO)

Abstract

Water vapor masers have been detected in over 150 galaxies. In at least 25% of these galaxies, the masers are arranged in thin, sub-parsec disks orbiting the central supermassive black holes in AGNs. Maser disks can be mapped with VLBI, and in fact they provide the only means of mapping gas in AGNs on such scales, directly. So far, twenty have been mapped. The masers trace Keplerian orbits about the nucleus, and provide gold-standard masses of the central black holes. In several cases, they can be used to measure the distance to the host galaxy, geometrically. The Megamaser Cosmology Project (MCP) focuses on discovering such maser disks and using them to measure galaxy distances, and hence the Hubble Constant. The MCP is playing a critical role in resolving the apparent discrepancy between standard-candle based measurements of H0 and the value predicted by Planck measurements of the CMB.

17/06/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Experimental Investigations of Molecule Formation on Surfaces of Astrophysical Interest
Valerio Pirronello (University of Catania)

Abstract

The abundance of most of the molecules observed in interstellar clouds can be explained by chemical reactions occurring in the gas phase; however some key species, like for instance H2 (the most important molecule in the Universe) and CO2 , cannot be formed efficiently enough by gas phase reactions. Their abundance can be understood when reactions occurring on the surface of interstellar grains (that act as catalysts) are taken into account. Furthermore several other species (like for instance water, formaldehyde, methanol and so on), for which gas phase formation routes do exist, are synthesized more efficiently on grain surfaces.

Surface reactions have been for long neglected or taken into account only on a theoretical ground, while due to intrinsic difficulties experimental investigations, in conditions and on solids that can be considered realistic analogues of interstellar grains, started to be tackled only rather recently.

In this talk I will present together with some well consolidated results on the formation of molecular hydrogen, that we started to study in the nineties, also some very recent and interesting results on other important species.

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — The importance of spin-state chemistry in star formation
Paola Caselli (MPE)

Abstract

Molecules are unique tools to study the dynamical and chemical evolution of interstellar clouds and star forming regions.  A detailed understanding of the chemical processes is needed to exploit the data fully. I shall review some recent observational and theoretical work on dense cloud cores, pointing out the importance of spin-state chemistry to unveil crucial parameters such as the ionization fraction and the cloud age.


12/06/14 (Thursday)
16:15, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Presupernova evolution, explosion and nucleosynthesis of rotating massive stars at various metallicities
Marco Limongi (INAF - Rome Observatory)
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Abstract

I will present an overview of the evolution of massive stars from the pre main sequence phase up to the onset of the iron core collapse, their hydrostatic and explosive nucleosynthesis and their final fate. The models extend in mass between 13 and 80 Msun, have initial metallicities corresponding to [Fe/H]=0,-1,-2,-3 and have initial rotation velocities corresponding to v=0, 150 and 300 km/s.

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05/06/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The structure of the Universe in the last 1Gyr
Adi Nusser (Technion, Haifa, Israel)

Abstract

Analysts of the low-z observations of the Universe are fortunate: a. The late-time large scale structure is traced by "softly" evolving mature galaxies. This cosmic coincidence greatly simplifies the relation between galaxies and the dark matter. b. In addition to traditional galaxy redshift surveys, good quality measurements of peculiar motions of galaxies are now availalbe. A critical assessment of the observed large scale structure will be presented, starting from the Local Group of galaxies within 5 Mpc, out to z 0.1. Traditional and new probes will be shown to support the standard paradigm of structure formation, but not without raising a few eyebrows. Mild tweaks will be discussed as well as potential constraints on alternative theories of gravity.

04/06/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Geometry from quantization: a simple overview
Michael Kay (LMU)
03/06/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Detection of B-mode polarization at degree angular scales using BICEP2
Denis Barkats (ESO - ALMA)

Abstract

BICEP2 recently reported a detection of B-modes in the CMB polarization 
at degree angular scales. This B-mode pattern is widely interpreted as 
the likely signature from primordial gravitational waves, consistent 
with those predicted to arise in the first 10^-34 seconds of the history
 of the universe, stretched from quantum to classical scales by the 
exponential expansion of cosmic inflation.
BICEP2 is a CMB polarimeter that was specifically designed to search for the elusive signal from inflationary gravitational waves in the B-mode power spectra around l = 80. BICEP2 has accumulated 3 years of data from the South Pole from 2010 to 2012, integrating continuously on a low-foreground region of effective size 1% of the whole sky. I will describe the experimental strategy, tests for foreground and systematics contamination, and results in the map and power spectra. The reported B-mode spectrum is well fit by a lensed-LCDM plus tensor theoretical model with tensor/scalar ratio r = 0.20 +0.07 -0.05 with r = 0 is strongly disfavored.
10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Probing protoplanetary disk evolution with accretion measurements
Carlo Felice Manara (ESO)

Abstract

Planet formation happens in evolving protoplanetary disks surrounding forming stars. The interaction between the star and the disk in the early phases of evolution puts strong constraint on the capability of such systems to form planets. This interaction happens mainly through accretion of matter from the disk onto the star, and its most significant signatures are the continuum excess in the UV part of the spectrum and the presence of various emission lines. With the advent of the VLT/X-Shooter instrument, the excess emission in the UV due to accretion is being studied simultaneously with the signatures in the visible and in the near-infrared, finally giving a complete view of this phenomenon. 
From the study of the accretion mechanism in objects located in nearby young stellar clusters we are able to understand the typical evolution of disks and its implication on the planet formation mechanisms. I will present the results obtained with the spectroscopic surveys carried out with the VLT/X-Shooter in many nearby young star clusters (e.g., Lupus, rho-Ophiuci, sigma-Ori) and aimed at studying objects with different stellar properties and at various stages of disk evolution, including the transitional disk phase.

May 2014

28/05/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Large scale structure formation with the Schroedinger method
Cora Uhlemann (LMU)

Abstract

When describing large-scale stucture formation of collisionless dark matter one is interested in the dynamics of a large collection of identical point particles that interact only gravitationally. Via gravitational instabilty initially small density perturbations evolve into eventually bound structures, like halos that are distributed along the cosmic web. Even though this problem seems quite simple from a conceptual point of view, no general solution is known and one has to resort to N-body simulations. Analytical methods to describe structure formation are in general based on the dust model which describes cold dark matter as a pressureless fluid characterized by density and velocity. This model works quite well up to the quasi-linear regime but necessarily fails when multiple streams form that are especially important for halo formation but lead to singularities in the model. We employ the so-called Schrödinger method to develop a model which is able to describe multi-streaming and therefore can serve as theoretical N-body double and replacement for the dust model.

27/05/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The astrophysics of the PLATO space mission
Malcolm Fridlund (DLR)

Abstract

With the selection of PLATO as ESA’s M3 mission, the situation for astronomical observations of exoplanets from space is going in the right direction. At the moment the global astronomical community can prepare for a number of missions - CHEOPS, TESS, JWST and PLATO - that will provide the next necessary step on the way to understand exoplanets, stars and eventually ourselves. A new science of truly comparative planetology is being born at the moment and will surely thrive fully in the 2020:ties.

PLATO, intended for a launch in the first quarter of the year 2024, will push the precision of transit photometry to the limit where it is possible to simultaneously detect the astroseismic p-modes from the host star as well as the high precision shape of the transit light curve. This will allow the determination of masses and radii of the star and planet to an accuracy of a few percent. The actual comparison between different types of planets then finally becomes possible. At the same time, it will be feasible to determine the age of exoplanetary systems to a precision of less than 10% (or typically 250 Myears), an order-of-magnitude improvement for main sequence solar type stars.

PLATO will also put strong requirements on the required ground based follow-up program, and the preparation for this will have to begin within the near future.

22/05/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Cepheids as standard candles: a 1% distance scale for cosmology?
Pierre Kervella (LESIA, Observatoire de Paris)

Abstract

Thanks to their period-luminosity (PL) relation, Cepheids provide one
of the most accurate empirical distance scales, applicable up to at
least 20 Mpc. They are in particular at the base of the calibration of
secondary distance indicators, such as SN Ia.

In the era of precision cosmology, the calibration of the PL relation
at the 1% level is however complicated by the fact that long-period
Cepheids are too distant for direct and accurate trigonometric
parallax measurements (even for GAIA). The most accurate Cepheid
distances are currently based on the classical Baade-Wesselink (BW)
technique, which in turn relies on surface brightness-color relations
and a velocity conversion factor (the projection factor). To bypass
this dependance, we applied a novel technique based on the measurement
of the changes in angular diameter of Cepheids using optical
long-baseline interferometry. I will present the results we obtained
from interferometric observations of a sample of Galactic Cepheids,
with an emphasis on the projection factor employed in BW techniques. I
will also briefly discuss the influence of circumstellar envelopes on
these observations, their potential impact on the distance scale, and
present the special case of the dust-embedded Cepheid RS Puppis.

As they are relatively massive stars, Cepheids are often members of
multiple systems. We discovered that they also host bright
circumstellar envelopes, particularly at infrared wavelengths.
Binarity and envelopes can both affect the apparent brightness of
Cepheids, potentially biasing the calibration of the PL relation. But
these properties also provide us with new tools to measure geometric
distances (through binary orbits), and to better understand the
evolution and complex dynamics of the Cepheid atmospheres. I will
present our recent results and ongoing programs on this front.

 

12:30, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Bob Fosbury (ESO Astronomer Emeritus)

Abstract

Choreographed by Carl Sagan in 1990, the Voyager 1 science team instructed the spacecraft to take a "Portrait of the Planets" from outside the orbits of Neptune and Pluto. Nestling in a beam of sunlight scattered within the camera, the Pale Blue Dot became an icon of human civilization. In this talk we ask what an alien observer, on a planet circling an M-dwarf star nearly eight light years from the Sun, might learn about Earth from a careful study of its blue colour. Although one of three blue planets in the Solar System, our alien would quickly realise that Earth's blue had a very different origin from the swirling, methane-tinted atmospheres of Uranus and Neptune. Although it is highly likely that the first extraterrestrial life to be discovered will be in an environment very different to Bejing or New York, the prospect of discovering 'Earth's twin' is a strong driver for exoplanet searches and characterisations.

12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — Precision experiments at low energies and the early Universe
Peter Fierlinger (TUM)

Abstract

Extreme measurement precision at very low energies provides an alternative path to search for physics beyond the Standard Model of particle physics. Although very different information is obtained from such relatively small-scale experiments compared to accelerator physics, they potentially probe much higher energy scales. Next to a more general discussion of concepts and ideas in this field, several approaches based locally in Munich will be discussed.

20/05/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — The z=0.89 molecular-rich absorber toward the lensed blazar PKS1830-211
Sebastien Muller (Onsala)

Abstract

The line of sight toward the lensed blazar PKS1830-211 is remarkable for several reasons and offers the opportunity to address many astronomical interests. The 40+ molecules detected so far in the z=0.89 absorber in front of the blazar do not only tell us about the physico-chemical conditions of the molecular gas in a galaxy at a lookback time of more than half the current age of the Universe, but they can also be used as powerful cosmological probes. Based on recent radio observations, including ALMA cycle 0 data, I will present
1) a precise and accurate measurement of the cosmic microwave background temperature at z=0.89;
2) constraints of the cosmological variations of fundamental constants such as the proton-to-electron mass ratio;
3) measurements of isotopic ratios at z=0.89, and 4) I will argue that lensed blazars such as PKS1830-211 offer the unique opportunity to monitor the activity of a blazar black-hole down to unprecedented accuracy.

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Turbulence in Giant Molecular Clouds: The effect of photoionization feedback
Dominika Boneberg (USM)

Abstract

Giant Molecular Clouds are observed to be turbulent, but without a driving mechanism this turbulence will quickly die away. We analyze the velocity field of simulations of star forming regions and find strong indications that photoionization feedback by massive young stars can drive turbulence.

15/05/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Relativistic Winds in Quasars
George Chartas (College of Charleston)
Download video |

Abstract

Some of the most fascinating properties of quasars arise from the strong gravitational field that dominates over all other forces near the supermassive black hole (SMBH). Observations of the X-ray spectra of quasars have the potential of testing the theory of General Relativity in a region of strong gravity, constraining the structure of the X-ray emitting region, and further our understanding of the quasars' role in feedback, quenching of star formation and galaxy evolution. I will present results from the detection of near-relativistic winds launched near the innermost stable circular orbits of SMBHs. A recent detection of a powerful wind in the X-ray bright quasar HS 0810 strengthens the case that quasars play a significant role in feedback. The two main mechanisms proposed for accelerating ultra-fast quasar outflows are radiation and magnetic driving. I will briefly review these acceleration mechanisms and test them against current observations of ultra-fast outflows.

Video

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13/05/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The Hot Horizontal Branch Stars in NGC 288 - Confusion, Diffusion and Why You should never Give Up!
Sabine Moehler (ESO)

Abstract

In my talk I will present the analysis of medium-resolution spectra of hot horizontal branch stars in the metal-poor globular cluster NGC 288. Equally important I will describe the pitfalls we encountered before arriving at our final results. In order not to spoil the talk no further details are given here.

08/05/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Accretion Disk Outbursts: MHD Simulations (Finally) Confront Reality
Omer Blaes (UC Santa Barbara)
Download video |

Abstract

Accretion disks around compact objects are responsible for some of the most powerful phenomena that we observe in the universe, from gamma-ray bursts to quasars. Stresses in the flow that transport angular momentum outward and allow gravitational binding energy to be released are central to the physics of these flows. For over twenty years, the dominant theoretical paradigm for these stresses is turbulence driven by an instability of weak magnetic fields embedded in the flow. Numerical simulations of this turbulence have revealed much about how these stresses might work, but until recently, they have not successfully explained (never mind predicted) the most significant quantitative observational constraints: the outburst time scales of dwarf novae and low mass X-ray binaries. I will describe recent progress on understanding the behavior of these systems through new simulations that incorporate the physics that is essential for exploring the physics of these phenomena.

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12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — No food, no star - the complex evolution of a galaxy star formation activity
Paola Popesso (TUM)

Abstract

The evolution of the star formation activity and, thus, the assembly of the stellar content of galaxies remain at the heart of galaxy evolution studies. It is now rather well established that most galaxies form stars at a "normal" level, dictated mainly by their stellar mass and regulated by secular processes. This is seen as a main sequence (MS) in the star formation rate(SFR)-stellar mass plane. The normalization of this sequence declines with time since z~2. However, we do not yet fully understand the processes that control this evolution, nor how individual galaxies evolve relative to it. While the existence of a MS may seem to suggest a simple and universal mode of star formation in galaxies (on average), the deviations indicate a more complex relation between galaxy SFRs, gas reservoir, external and internal mechanisms triggering or halting star formation. In this context Paola will discuss in particular the role of the "environment quenching" as the main external mechanism able to suppress the galaxy star formation activity.

07/05/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Making stars: Sodium laser guide stars in terrestrial astronomy
Roland Holzlöhner (ESO)

Abstract

Terrestrial astronomy suffers from wavefront distortion due to atmospheric turbulence: The resolution limit in the visible, depending on the site, lies in the range of 0.5-2 arcseconds, corresponding to the diffraction limit of a telescope with only 6-25cm clear aperture. The detrimental effect of turbulence can be significantly mitigated with the help of adaptive optics, in which the shape of one or several mirrors in the optical train is actively controlled using a real-time closed loop system. The control signal is derived from the continuous observation of a bright star in the telescope field of view with wavefront sensors and updated at a rate of 500-1000 Hz. Since many areas of the night sky lack sufficiently bright stars, it has become common in large telescopes such as ESO's Very Large Telescope (VLT) in the Atacama desert to employ laser guide stars (LGS). To make these, a powerful laser beam is propagated onto the sky parallel to the optical axis. Sodium LGS excite a diluted natural sodium layer in the mesosphere at 80-110km altitude through resonant fluorescence at 589nm and thus provide artificial beacons to adaptive optics. In the presentation Roland will discuss the involved physics and highlight some of the technical challenges.

06/05/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Absorption systems in cosmological simulations and their connection with galaxies
Alireza Rahmati (MPA)

Abstract

I will talk about the distribution of HI and metal absorbers in cosmological simulations and compare the simulation results with observations. I will further discuss the implications for the relation between absorbers and galaxies.
10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — The Mdot-M_* relation of pre-main-sequence stars: a consequence of X-ray driven disc evolution
Barbara Ercolano (USM)

Abstract

I will present results from our recent paper where we analyse current measurements of accretion rates on to pre-main-sequence stars as a function of stellar mass, and conclude that the steep dependence of accretion rates on stellar mass is real and not driven by selection/detection threshold, as has been previously feared. These conclusions are reached by means of statistical tests including a survival analysis which can account for upper limits. The power-law slope of the Mdot-M_* relation is found to be in the range of 1.6-1.9 for young stars with masses lower than 1 M⊙. The measured slopes and distributions can be easily reproduced by means of a simple disc model which includes viscous accretion and X-ray photoevaporation. We conclude that the Mdot-M_* relation in pre-main-sequence stars bears the signature of disc dispersal by X-ray photoevaporation, suggesting that the relation is a straightforward consequence of disc physics rather than an imprint of initial conditions.

April 2014

29/04/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The maturing stellar populations of X-ray selected AGN host galaxies
Antonio Hernan-Caballero (Inst. de Fisica de Cantabria, Spain)

Abstract

Comparative studies of the restframe colours of active and inactive galaxies have shown no clear differences when the stellar mass-dependency of the AGN fraction is taken into account. This is in contrast to the observation of a lower frequency of AGN in quiescent galaxies, and specific star formation rates in AGN hosts that are comparable to those in star-forming galaxies at the same redshift. In this talk I will show recent results from the Survey for High-z Absorption Red and Dead Sources (SHARDS) that provide an interpretation of these two apparently contradictory observations.

24/04/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Archaeology of Exo-Terrestrial Planetary Systems
Jay Farihi (Institute of Astronomy, Cambridge)

Abstract

We now stand firmly in the era of solid exoplanet detection via Kepler and other state of the art facilities. Yet the empirical characterization of these most intriguing planets is extremely challenging. Transit plus radial velocity information can yield planet mass and radius, and hence planet density, but the bulk composition remains degenerate and completely model-dependent. Currently, the abundances of a handful of exoplanet atmospheres can be estimated from transit spectroscopy, or observed directly via spectroscopy, but probing only the most tenuous outer layers of those planets.

Fortunately, as demonstrated by Spitzer and complementary ground-based observations, debris disk-polluted white dwarfs can yield highly accurate information on the chemical structure of rocky minor planets (i.e. exo-asteroids), the building blocks of solid exoplanets. The white dwarf distills the planetary fragments, and provides powerful insight into the mass and chemical structure of the parent body.

This archaeological method provides empirical data on the assembly and chemistry of exo-terrestrial planets that is unavailable for any planetary system orbiting a main-sequence star. In the Solar System, the asteroids (or minor planets) are leftover building blocks of the terrestrial planets, and we obtain their compositions - and hence that of the terrestrial planets - by studying meteorites. Similarly, one can infer the composition of exo-terrestrial planets by studying tidally destroyed and accreted asteroids at polluted white dwarfs.

I will present ongoing, state of the art results using this unconventional technique, including the recent detection of terrestrial-like debris in the Hyades star cluster, as well as the detection of water-rich planetesimals that may represent the building blocks of habitable exoplanets.

10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Are "Low Luminosity Objects" Young Protostars?
Tien-Hao Hsieh (MPIfR, Bonn / National Tsing Hua Univ., Taiwan)

Abstract

Low Luminosity Objects (LLOs) are the faintest protostars with internal luminosity Lint < 0.2 Lo. The nature of Low Luminosity Objects is still unclear. Their low luminosities hints that they could be either very young, very low-mass, or even very young and low-mass protostars (i.e., proto-brown dwarfs). In addition, they could be at the quiescent stage of episodic accretion process. To examine whether LLOs are truly young protostars, we study the evolutionary status of 16 LLOs with radio observations. We used 12M telescope and Submillimeter Telescope (SMT) of Arizona Radio Observatory (ARO) to observe N2D+ and N2H+ line emission, and derived the N2D+/N2H+ abundance ratio which has been argued to be an evolutionary indicator in the early stage. We further use RADEX, a non-LTE molecular radiative transfer code, to derive the properties of molecular cores, such as volume density (nH2) and kinematic temperature (Tkin) which are believed to increase as a protostellar core evolves. We therefore study the relation between these age indicators and N2D+/N2H+ and our results suggest that most of our target LLOs are likely to be extremely young protostars.

23/04/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — The safest routes to islands Beyond the Standard Model
Francesco Riva (Ecole Polytechnique Federale de Lausanne)

Abstract

In the absence of direct discoveries, physics Beyond the Standard Model (BSM) can be parametrized by an effective field theory as an expansion in inverse powers of the New Physics scale. This expansion serves as a guide for precision searches. In fact, the leading term in this expansion coincides with the standard model: its symmetries and relations are well known and are being tested at colliders. In this talk Francesco will discuss the next order in the expansion, that parametrize the largest effects that can be expected from physics BSM. He will show that many relations persist, implying that not all the observables that we experimentally test are independent. For example, deviations in the differential distribution of h->Vff decays, are correlated with deformations of the couplings of vectors to fermions, that are already well measured at LEP at CERN.

22/04/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The EAGLE Universe
Richard Bower (Durham University, UK)

Abstract

The EAGLE (Evolution and Assembly of Galaxies and their Environments) project is a suite of hydrodynamic simulations of the Universe. The simulations take into account the full range of baryonic physics, including metal dependent gas cooling, star formation, supernovae and black hole formation. The resolution of the simulations is sufficient to resolve the onset of the Jeans instability in galactic disks, allowing us to study the formation of individual galaxies in detail. At the same time the largest calculation simulates a volume that is 100 Mpc on each side, exploring the full range of galaxy environments from the isolated dwarves to rich galaxy clusters.

A key philosophy of the simulations has been to use the simplest possible sub-grid models for star formation, black hole accretion and feedback from supernovae and AGN. Efficient feedback is achieved without hydrodynamic decoupling of particles. The small number of parameters in these models are calibrated by requiring that the simulations match key observed properties of local galaxies. Having set the parameters using the local Universe, I will show that the simulations reproduce the observed evolution of galaxy properties extremely well. The resulting universe provides us with deep insight into the formation of galaxies and black holes. In particular, we can use the simulations to understand the relationship between local galaxies and their progenitors at higher redshift and to understand the role of interactions between galaxies and the AGN that they host. I will present an overview of some of the most important results from the project.

16/04/14 (Wednesday)
16:30, TUM Institute for Advanced Study | ESO Garching
Cluster Universe Colloquium
Talk — Quantum Universe: Theory and Observations
Viatcheslav Mukhanov (LMU)

Abstract

In March 2014 Harvard astronomers announced the detection of primordial gravitational waves with the telescope of the BICEP2 collaboration at the South Pole. They studied the polarization properties of the cosmic microwave background radiation which showed imprints of so-called B modes, relics of gravitational waves of the inflationary phase of the Universe. One of the world experts in the field of inflation theories and Principal Investigator at the Excellence Cluster Universe, Viatcheslav Mukhanov (LMU), will present the significance of these findings for theoretical cosmology.

10/04/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Future prospects of the cosmic noon: mapping and resolving galaxy formation at its peak epoch
Taddy Kodama (NAOJ, Subaru Telescope)

Abstract

Our Mahalo-Subaru project has been mapping out star forming activities at 0.4
I will also present prospects from other on-going/future major programs using a wide range of facilities from optical to (sub)mm to increase samples and investigate in more detail the physics and mode of star formation.

09/04/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Answers in the light: High-resolution spectra and type Ia supernovae progenitors
Assaf Sternberg (TUM)

Abstract

A Type Ia supernovae is the very luminous thermonuclear explosion of a carbon-oxygen white-dwarf in a close binary system. Despite numerous studies, the nature of the companion star remains uncertain and under much debate. A main discriminant between the progenitor models that have been proposed is the predicted circumstellar environment in which the white-dwarf explodes. Therefore, studying the circumstellar environment of Type Ia supernovae can help us validate which progenitor channel, or channels, can lead to these brilliant events. High-resolution spectroscopy is currently the most promising method with which one can probe the circumstellar material around a Type Ia supernova, while using the supernova as back-light. This talk will present an overview of the high-spectral-resolution studies that have been performed in recent years, what we have learned from them, and what we can do in the future to get us closer to solving the long standing progenitor mystery.

08/04/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — XXL: the ultimate XMM extragalactic survey
Marguerite Pierre (Service d'Astrophysique, CEA Saclay)

Abstract

At the end of 2010, a Very Large XMM programme - the XXL survey - was granted in order to map two regions of 25 deg2 each at medium sensitivity. This will lead to the detection of several hundreds of clusters of galaxies and of some 30 000 AGNs with well defined selection functions. Since 2012, an ESO Large Programme is performing the spectroscopic identification of the galaxy clusters. After reviewing the scientific motivations, we describe the some 540 XMM observations, the associated multi-wavelength follow-up and simulation programmes. We especially underline the cosmological goals of the project involving cluster number counts, large-scale studies with clusters and AGNs as well as the systematic search for very distant clusters in a multi-lambda space. This will be the occasion to review in some detail the still hotly debated question of the proper use of clusters of galaxies for cosmology, as recently revived by the tension between the cosmological constraints from the Planck CMB and the Planck clusters. We describe a new method for the cosmological analysis of cluster surveys that bypasses the traditional mass calculation step. We present the first scientific results.

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Shockingly low water abundances in Herschel / PACS observations of low-mass protostars in Perseus
Agata Karska (MPE)

Abstract

Shocks produced in the outflows from young protostars strongly influence the process of star formation, yet are not well quantified. Recent far-infrared observations of molecules with Herschel offer a unique opportunity to constrain the shock parameters, such as a type of shock (continuous / jump), shock velocity and pre-shock density of envelope material. However, various authors found very different shock characteristics towards a few low-mass protostars studied so far. Here, I will present a survey of a large (~20 objects) and uniform (same distance, age, environment) sample of protostars located in Perseus Molecular Cloud observed as a part of the "William Herschel Line Legacy" program. Our analysis of different molecular line ratios shows that the currently available shock models cannot explain all the observations. The water abundances are too high, indicating that additional physical processes need to be included in the models.

03/04/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Characterizing Massive Black Holes through Stellar Tidal Disruption
Enrico Ramirez Ruiz (University of California)

Abstract

A star interacting with a massive black hole cannot be treated as a point mass if it gets so close to the black hole that it becomes vulnerable to tidal distortions and even disruption. When a rapidly changing tidal force starts to compete with a star's self-gravity, the material of the star responds in a complicated way. This phenomenon poses an as yet unmet challenge to computer simulations. The art of modeling the tidal disruption of stars by massive black holes forms the main theme of my talk. Detailed simulations should tell us what happens when stars of different types get tidally disrupted, and what radiation a distant observer might detect as the observational signature of such events.

01/04/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — The nature of dusty star-forming galaxies (a post-Herschel view)
Lingyu Wang (Durham University, UK)

Abstract

Combining Herschel with data at other wavelengths enables us to study different physical processes that are at work. In my talk I will present results from two recent projects that I have (co-)led. The first project probes the co-evolution of black hole growth and star formation by studying the cross-correlation between optically selected type 1 SDSS quasars and the CIB. For the first time, we detect not only the sub-millimetre emission of the quasars themselves which dominates on small scales but also the correlated emission of dusty star-forming galaxies on larger scale. The correlated emission comes from satellite galaxies in the same halo as the quasar and galaxies which reside in separate halos correlated with the quasar-hosting halo. The second project looks at the cross-correlation between the CIB and the cosmic microwave background (CMB). Apart from the dusty star-forming galaxies which are present in both the CIB and CMB maps, we also detect the cross-correlation between the thermal Sunya'ev-Zeldovich (tSZ) signal and the CIB sourced by dusty star-forming galaxies. The tSZ-CIB cross-correlation signal not only provides constraints on the level of star-formation activity in massive systems, but also significantly improves constraints on the kinetic SZ which is of great interest for studying the duration of reionization.

March 2014

28/03/14 (Friday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — What is the most powerful and persistent engine of Nature?
Gabriele Ghisellini (INAF - Astronomical Observatory of Brera)

Abstract

We realized long ago that accretion onto compact objects was a more efficient engine than thermonuclear reactions. Relativistic jets, however, seem to carry more power than what accretion can provide. I will present the evidences for this statement by considering the jets of blazars, and finding robust results about their power.

27/03/14 (Thursday)
16:15, Auditorium Eridanus (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Probing the Primordial Universe with Galaxy Clustering and Shapes
Fabian Schmidt (MPA)
Download video |

Abstract

One of the primary goals of cosmology is to elucidate the origin of structure in the Universe. The currently most widely accepted paradigm is the theory of inflation - an epoch of extremely rapid expansion at a very early phase in the history of the Universe. A significant effort in cosmology is directed toward testing this hypothesis. I will show how we can use the clustering of galaxies, as well as statistics of their observed shapes, to learn about the physics of inflation, as well as alternative scenarios. This provides a fascinating connection between the largest observable scales in the cosmos and physics at energies far beyond the reach of accelerators on Earth.

Video

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12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — Embedding Peanuts in Galaxies
Panos Patsis (Academy of Athens)

Abstract

Many disk galaxies observed edge-on have a boxy or peanut-shaped central structure. The Milky Way is one of them. We speak about "b/p-bulges" that in some cases have even the morphology of X-shaped cores. They are considered being parts of bars. The talk will be about the dynamical mechanisms that can create these structures in galactic disks. Their orbital content will be discussed and it will be explained how the theory of chaos helps in understanding the robustness of boxes and peanuts.

25/03/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Multi-wavelength models of galaxy formation: evidence for a varying IMF?
Cedric Lacey (Durham University, UK)

Abstract

I will present latest results from our work on multi-wavelength modelling of the evolution of galaxies. The work combines a theoretical model of galaxy formation based on Lambda-CDM with a radiative transfer calculation of the reprocessing of stellar emission by dust in galaxies. Our previous work implied the need for a top-heavy IMF in starbursts in order to explain the number counts and redshifts of sub-mm galaxies in this framework, once the observational constraints from the present-day galaxy luminosity function at optical and near-IR wavelengths were included. We have revisited this using an improved galaxy formation model, which includes a more realistic treatment of star formation, as well as feedback from AGN. In the new work, we also impose the constraint that the model reproduces the observed evolution of the galaxy luminosity function at near-IR wavelengths. We find that variations in the IMF still seem to be required when we try to match all of these observational constraints simultaneously.

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Detectable Glycine in Solar-type System Precursors: Implications for ALMA Band2
Izaskun Jimenez-Serra (ESO)

Abstract

Glycine (NH2CH2COOH) is the simplest amino acid. Its detection is key to understand the formation mechanisms of pre-biotic molecules in the interstellar medium and their subsequent delivery onto planetary systems. Glycine has extensively been searched for toward hot molecular cores, although these studies did not yield any firm detection. In contrast to hot cores, low-mass star forming regions, and in particular their earliest stages represented by cold pre-stellar cores, may be better suited for the detection of glycine. In this work, we have carried out 1D spherically symmetric radiative transfer calculations of the glycine emission expected to arise from a low-mass pre-stellar core, L1544. Water vapour has recently been reported toward this core, indicating that a small fraction of the grain mantles in L1544 (~0.5%) has been injected into the gas phase. Assuming that glycine is photo-desorbed together with water in L1544, and considering a solid glycine abundance of 1E−8, our calculations reveal that several glycine lines between 67GHz and 85GHz have detectable peak intensities larger than 10mK. The development of the receivers for ALMA Band 2+3 will open up the possibility to detect glycine and other pre-biotic molecules at the earliest stages of the formation of proto-Solar systems, possibly allowing the connection between the pre-biotic chemistry in the ISM and its subsequent delivery onto protoplanetary systems.

20/03/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Massive black holes: dynamics, spin evolution and gravitational wave detection
Alberto Sesana (AEI Potsdam)

Abstract

Within this decade the detection of gravitational waves (GWs) may be a reality, opening a completely new window on the Universe. The low frequency window will be dominated by signals emitted by a cosmological population of massive black hole binaries (MBHBs). In this talk I will review several aspect of MBH physics focusing in particular on spin evolution and gravitational wave emission. In the first part of the talk, I will present a model linking the accretion flow to the kinematical properties of the galaxy hosts, which produces MBH spins in broad agreement with current observations. In the second part, I will pay particular attention to the prospect of GW detection from MBHBs with pulsar timing arrays and/or future space based interferometers.

19/03/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — The Majorana nature of massive neutrinos as a possible hint for new physics
Aurora Meroni (U Roma, INFN Frascati)

Abstract

Determining the nature - Dirac or Majorana - of massive neutrinos, possibly related to a New Physics scale beyond that predicted by the Standard Model is a fundamental problem under study. Significant experimental efforts have been made to unveil the possible Majorana nature of massive neutrinos by searching for neutrinoless double beta decay with increasing sensitivity. These constraints, together with the results from beta-decay experiments and in light of the recent (and future) cosmological observations can be combined in order to extract information on new possible couplings in the Lagrangian of particle interactions, changing the total lepton charge L=L_e + L_\mu + L_\tau by two units. Further if it will be experimentally established the Majorana nature of massive neutrinos, via the observation of the double beta decay, it will be possible to test the compatibility of the usual 3-neutrino scenario with the possible existence of 1 or 2 additional sterile neutrino states with masses at the eV scale (the so called 3+1 and 3+2 schemes) and to study the implications of all this on the general properties of the neutrino mass matrix.

18/03/14 (Tuesday)
12:00, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Ground based optical tracking of the Gaia satellite
Martin Altmann (ZAH Heidelberg)

Abstract

The recently launched Gaia satellite mission will provide astronomers with an astrometric dataset comprising data on 1 billion stars of unprecedented precision. In order to fully exploit the capabilities of Gaia, the location and velocity vector of the space craft itself need to be known to a high degrees, more precisely than conventional means can deliver. For this reason a network of small to medium telescopes was set up to track the satellite astrometrically. The overall structure and strategy of this campaign will be described in this presentation. Since the launch of Gaia, the GBOT group had to enter a process of redefinition and reassessment of its strategy after the target turned out to be ~3 mags fainter than anticipated. The actions taken and the current status of the effort will be reviewed and commented on.

10:00, Fornax (ESO HQ, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — The formation of filamentary bundles in turbulent molecular clouds
Nick Moeckel (USM)

Abstract

The classical picture of a star-forming filament is a near-equilibrium structure, with collapse dependent on its gravitational criticality. Recent observations have complicated this picture, revealing filaments as a mess of apparently interacting subfilaments, with transsonic internal velocity dispersions and mildly supersonic intra-subfilament dispersions. How structures like this form is unresolved. I will discuss a study of the velocity structure of filamentary regions in a simulation of a turbulent molecular cloud. I'll talk about two main findings: first, the observed complex velocity features in filaments arise naturally in self gravitating hydrodynamic simulations of turbulent clouds without the need for magnetic or other effects. Second, a region that is filamentary only in projection and is in fact made of spatially distinct features can displays these same velocity characteristics. The fact that these disjoint structures can masquerade as coherent filaments in both projection and velocity diagnostics highlights the need to continue developing sophisticated filamentary analysis techniques for star formation observations.

13/03/14 (Thursday)
16:15, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — AGN feedback through the cosmic times
Fabrizio Fiore (INAF - Astronomical Observatory of Rome)

Abstract

Why do black holes in galactic nuclei have masses proportional to bulge masses and luminosities? Why did galaxies at a certain point of their cosmological evolution, stop to form stars? What is the path(s) and the mechanism(s) leading the transition from gas rich, star-forming galaxies, to red passive galaxies, deprived of all their gas? Theory and few observations suggest that AGN driven super winds (=feedback) play a major role in all these transformations. The two main building blocks of this scenario are: 1) AGN outflows, which inject energy in their environment; 2) the interaction of these flows with the galaxy interstellar matter, and its physical/chemical/geometrical modification.

I will first review AGN outflows seen in different gas phases and at different scales. I will then present searches for "direct" evidence of AGN feedback in bright nearby AGN, linking accretion and ejection occurring on sub-parsec scale in galaxy nuclei to the transformations occurring in the rest of the galaxy. I will finally discuss the perspectives of extending these studies up to z=1-3, the golden epoch of AGN and galaxy activity.

12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — SUSY, where are you? The concept of supersymmetry and the status of experimental searches
David Straub (TUM)

Abstract

Supersymmetry can be seen as the only way to non-trivially extend the symmetries of space-time (without increasing the number of dimensions). But besides being interesting conceptually, supersymmetry also has interesting phenomenological consequences. Supersymmetrizing the Standard Model, one finds that gauge couplings extrapolated to very short distances unify and a candidate for the dark matter of the universe emerges. Most importantly, supersymmetry is the only known way to reconcile an elementary Higgs boson - that we seem to have just discovered - with the presence of new physics at high energy scales, that is required for many reasons, without excessive fine-tuning in fundamental parameters. So far however, no signs of supersymmetric partners of the known particles have shown up at the 8 TeV LHC, and rumours about the demise of supersymmetry are spreading. David will give a critical review of the motivations for and the state of low-energy supersymmetry after 3 years of LHC.

12/03/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Massive neutrinos and the tension between Large Scale Structure and the Cosmic Microwave Background
Richard Battye (University of Manchester)

Abstract

There appear to be tensions between published measurements of the amplitude of density fluctuations on large scale made by the CMB temperature anisotropies and on smaller scales by large-scale structure probes. These include cluster counts, weak gravitational lensing (both of the CMB and galaxies) and redshift space distortions. We discuss this tension and the possible explanations. These include incorrect interpretation of the observations and the possible addition of new physics to the standard model of cosmology. In particular we calculate the neutrino masses (both for active and sterile species) that would be need to resolve the discrepancy. Prime facie there is a preference of around 4 standard deviations for non-zero neutrino masses.

11/03/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — An advanced scattered moonlight model for Cerro Paranal
Amy Jones (University of Innsbruck)

Abstract

In the current era of precision astronomy, a complete sky background model is crucial, especially as the telescopes become even larger in the next decade. Such a model is needed for planning observations as well as understanding and correcting the data for the sky background. We have developed a sky model for this purpose, and it is the most complete and universal sky model that we know of to date (Noll et al. 2012). It covers a wide range of wavelengths from 0.3 to 30 microns up to a resolution of 1,000,000 and is instrument independent.

The brightest natural source of optical light at night is the Moon, and it is the major contributor to the astronomical sky background. We have an improved scattered moonlight model (Jones et al. 2013), where all of the components are computed with physical processes or observational data with less empirical parametrizations. This model is spectroscopic from 0.3 to 2.5 microns and was studied with a FORS1 (Patat et al. 2008) and dedicated X-Shooter data set. To our knowledge, this is the first spectroscopic model extending into the infrared.

I will introduce the sky background model and scattered moonlight model. Then I will go into more detail about the scattered moonlight model and present its current status as well as its performance in the optical and near-infrared.

10/03/14 (Monday)
00:00, Garching | ESO Garching

Abstract

This workshop aims to bring together the optical/near-infrared, millimetre and radio communities working on 3-dimensional extragalactic data, following on from the similarly themed 2008 workshop. Science topics are centered on both gas and stars in galaxies and examples include dynamics, AGN and supermassive black holes, high redshift galaxies and deep fields. Tools to visualise and analyse multi-wavelength data cubes will also be discussed. In association with the workshop, three parallel user workshops on reduction and analysis of 3D data from KMOS, MUSE and ALMA will be held. Further details can be found here. The abstract and registration deadline is 1 December 2013.

06/03/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The Astrophysics of Stellar Clusters
Melvyn Davies (Lund Observatory)

Abstract

Stellar clusters are common. Globular clusters contain some of the oldest stars, whilst the youngest stars are found in OB associations or in other clusters associated with recent star formation. Such crowded places are hostile environments: a large fraction of stars will collide or undergo close encounters. I will explain how stellar clusters are factories for producing exotic objects, including potentially intermediate-mass black holes which can grow into supermassive black holes in galactic nuclei. I will also discuss how planetary systems similar to our own solar system are vulnerable within stellar clusters due to interactions with other stars. Thus by studying stellar clusters we will learn more about the rarity of planetary systems similar to our own solar system. I will explain how the depletion of red giants in the very centre of our own galaxy may tell us something about its history.

04/03/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Understanding AGN clustering: the need for two accretion modes
Nikolaos Fanidakis (MPIA Heidelberg)

Abstract

AGN inhabit a wide range of dark-matter halo environments; from the centres of clusters, where radio galaxies reside, to average Milky-Way like haloes in which quasars are found. In my talk, I will demonstrate that the variety of AGN environments can be explained when more than one accretion modes are responsible for fuelling the growth of black holes. I will show this by means of semi-analytic modelling, combined with detailed SPH simulations of galaxies in a Λ cold dark matter universe with AGN feedback. With these tools, I will explain how the large scale environment of AGN depends on luminosity and AGN type, and I will demonstrate how AGN can be used, along with line-emitting galaxies, to pinpoint the location of galaxy protoclusters in the high-redshift Universe.

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — Filaments in Serpens
Veronica Roccatagliata (USM)

Abstract

Filamentary molecular structures are thought to be the consequence of thermal and dynamical instabilities caused by collisions of large-scale warm flows or by the collision of two Giant Molecular Clouds. A unique laboratory to discriminate the origin of the filaments is represented by the Serpens molecular cloud. By reducing and analyzing the Herschel far-infrared observations of the Serpens core region we revealed for the first time a network of filaments converging into the core cluster. This region is the ideal region to study all the processes of star formation, from the first stages of still in-falling gas to pre-/proto-stellar gaseous and dusty condensations, as well as already formed young stars. In this talk I will present the Herschel PACS and SPIRE mosaics of this region. The temperature and column density maps of the region enable us to characterize the cloud structure, as well as the filaments network converging into the central core cluster. I will present also the results of the comparison of our analysis with simulations of turbulent molecular clouds where very similar structures form on timescales of roughly on one cloud free-fall time.

February 2014

27/02/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — What did we learn about the Milky Way during the last decade, and what shall we learn using Gaia and LSST?
Zeljko Ivezic (University of Washington)
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Abstract

Studies of stellar populations, understood to mean collections of stars with common spatial, kinematic, chemical, and/or age distributions, have been reinvigorated during the last decade by the advent of large-area sky surveys such as SDSS, 2MASS, RAVE, and others. These data, together with theoretical and modeling advances, are revolutionizing our understanding of the nature of the Milky Way, and galaxy formation and evolution in general. These recent developments have made it clear that the Milky Way is a complex and dynamic structure, one that is still being shaped by the merging of neighboring smaller galaxies. I will review the progress over the last decade, including the mapping of stellar counts, metallicity and kinematics distributions, interstellar dust using extinction of stars, and dark matter halo using Jeans equations. I will conclude by briefly discussing new breakthroughs expected from Gaia and LSST surveys, which will improve measurement precision manyfold, and comprise billions of individual stars.

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12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — Strange hadrons in a strongly-interacting environment: from nuclei ad astra
Kirill Lapidus (TUM)

Abstract

Measurements of hadron properties inside the nuclear environment give insight into the fundamental properties of the strong interaction in the low energy domain — confinement and broken chiral symmetry. An additional motivation to focus on the strange hadron species (kaons and hyperons) is given by the hypothesis of their appearance in the core of a neutron star. In this talk, Kirill Lapidus will outline the mechanisms and experimental constraints for the existence of strangeness in neutron stars and give an example of accelerator-based studies with a recent high-precision measurement of neutral kaons done at the HADES experiment (GSI, Darmstadt).

25/02/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — 3D hydrodynamical simulations of cool stars for the interpretation of the stellar surfaces images, the fundamental parameters, the stellar variability and the planet detection
Andrea Chiavassa (OCA, Nice)

Abstract

Nowadays, the development of the observational instruments is so high that became very sensitive to the details of stellar surface. The interpretation of the stellar surfaces images, the fundamental parameters, the stellar variability and the planet detection needs realist simulations of stellar convection. Three-­dimensional radiative hydrodynamics simulations of cool stars are essential to a proper and quantitative analysis of these observations. I will present how these simulations across the Hertzsprung-Russel diagram have been (and will be) crucial to prepare and interpret the spectrophotometric, interferometric, astrometric, and imaging observations.

20/02/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Type Ia supernova progenitors: what do we know and what not?
Gijs Nelemans (Radboud Univ. Nijmegen)
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Abstract

Type Ia supernovae are by no means rare, which together with the strong evidence that at least one white dwarf is involved, implies that their progenitors should be fairly common too. Yet it is still unclear what these are. There has been great progress in several observational aspects of this issue. In addition the traditional division between "single" and "double" degenerate models has been challenged or at least complicated by a flurry of new possible progenitor models. I will give an overview of these developments and focus on the implications for our understanding of binary evolution. Finally I will use this to discuss other compact binary populations in the context of Gaia and as gravitational wave sources.

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18/02/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — HI lines in Young Stellar Objects: a probe of accretion and circumstellar properties
Simone Antoniucci (INAF - Astronomical Observatory of Rome)

Abstract

HI recombination lines at optical/near-IR wavelengths are a powerful diagnostic tool for the study of Young Stellar Objects (YSOs). On the one hand these lines are commonly used as a tracer of the mass accretion process, on the other hand they can also be employed to probe the physical properties of the gas in the circumstellar structures of young sources. In this talk I will present two different applications of the analysis of HI lines.

In the first part I will talk about the POISSON project (Protostellar Optical-Infrared Spectral Survey On NTT), a large low-resolution spectral survey of 150 YSOs from five different star-forming regions. In this work we used the near-IR HI lines as a proxy for the mass accretion rate (using empirical relationships connecting line flux to the accretion luminosity), thus obtaining a large database of values, which allowed us to study in particular the time evolution of the accretion rate.

In the second part I will present the preliminary results of the analysis of the HI decrements (i.e. the flux ratio of the lines of a series relative to one used as reference) observed on X-Shooter spectra of a sample of YSOs in Lupus. X-Shooter, with its broad wavelength coverage and moderate spectral resolution, is the perfect instrument to study the HI decrements of the Balmer, Paschen, and Brackett series. I will discuss the potential and limitations of the decrement analysis to provide information on the properties of the emitting gas and of the central source. In particular, I will focus on the correlations between the decrement shape, the observed line profiles, and the (stellar and accretion) properties of the objects.

13/02/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Fermi observations of blazars and constraints on the location of the gamma-ray emission region
Juri Poutanen (University of Turku, Finland)
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Abstract

The Large Area Telescope of the Fermi observatory has detected hundreds of AGNs, most of them are blazars. The GeV spectra of the flat spectra radio quasars were claimed to be inconsistent with a simple power law model or any smoothly curved models. Instead, a much better description was obtained with a broken power law, with the break energies of a few GeV. The sharpness and the position of the breaks could be well reproduced by absorption of gamma-rays via photon-photon pair production on He II and H I Lyman recombination continuum (LyC) and lines. In addition to the spectra from individual sources, we have created stacked redshift-corrected spectrum of several bright blazars. This spectrum shows a strong break at 20 GeV associated with hydrogen LyC. The detected breaks univocally prove that the gamma-ray emitting region lies with the BLR. This solves the long-standing question of the location of the gamma-ray production region.

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11/02/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Probing the formation conditions of massive clusters with formaldehyde
Adam Ginsburg (ESO)

Abstract

Massive clusters are important tracers of star formation in galaxies and
laboratories for the study of massive star formation and populations.  Because
they are rare and therefore distant, neither the population of these clusters
nor the details of their assembly are well understood.

I will discuss the importance of these clusters and some theoretical formation
mechanisms.  I will focus on two well-known regions, the massive forming
cluster W51 (not M51) and the potentially pre-star-forming cloud G0.253+0.016,
aka The Brick or The Lima Bean.  We have used formaldehyde as a probe of
physical conditions in these regions, mapping the gas density and examining
properties of the turbulence.  In The Brick, we find that the mean density is
very low, which explains the low observed star formation activity but raises
questions about the geometry and dust properties.  In W51, the density
structure is highly varied, from an n~100 cm^-3 infrared dark cloud to the
n~10^5 cm^-3 massive clump.  Overall, the gas seems to favor a more prolonged
formation scenario for massive clusters.
06/02/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Probing the end of the reionization epoch with the most distant galaxies
Laura Pentericci (INAF - Astronomical Observatory of Rome)

Abstract

The epoch of re-ionization is a fascinating time in the history of the Universe and many uncertainties still plague our understanding of when and how it occurred.

Lyman alpha emitting galaxies at high redshift offer a powerful probe to study both reionization and the process of galaxy formation. In particular Lyman alpha emission is an efficient tool for identifying young galaxies and for measuring how much neutral hydrogen is present in the environment of the galaxies, thus providing a reionization test that is independent of the Gunn-Peterson trough observations in quasar spectra.

The last few years have seen a number of discoveries that offered the first glimpse of the Universe at z =7, using both space and ground-based telescopes. I will review the most recent observational results on high redshift galaxies, namely Ly alpha emitters and Lyman break galaxies. In particular I will review the current constrains that we can place on the reionization epoch using the first statistical samples of spectroscopically confirmed z=7 Lyman break galaxies, the evolution of the luminosity functions and of the clustering strength of Ly alpha emitters.
I will finally present very recent ALMA observations which reveal, for the first time the nature and physical properties of these primeval galaxies that were probably responsible for the reionization.

05/02/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — TNOs are Cool - A Herschel survey of the trans-Neptunian region
Esa Vilenius (MPE)

Abstract

Trans-Neptunian objects (TNOs) are primitive remnants of the planetesimal disk from which the planets of our solar system formed. They are analogues to the parent bodies of dust in debris disks observed around other stars. Since 1992 about 1500 TNOs have been discovered but their basic physical properties have been challenging to measure. The richness of dynamical structure and varying physical properties set constraints to models of solar system formation and evolution. Herschel Space Observatory open time key program "TNOs are Cool" observed a sample of 130 TNOs at far-IR wavelengths around their thermal peaks. The results of radiometric modeling give albedo and size distributions as well as thermal properties. For binary systems we obtain an insight in their densities as a function of size. Thermal light curves of selected targets observed by Herschel are used together with the optical ones to solve the ambiguity between shape effects and albedo variegation. Possible correlations between physical properties, orbital elements and colors are also discussed.

04/02/14 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — Treasure trove OmegaCAM
Gijs Verdoes Kleijn (Leiden University)

Abstract

The OmegaCAM wide-field imager at the VST at ESO Paranal is over 2 years in science operations. Three public surveys are being observed in parallel: KiDS, ATLAS and VPHAS+. Together with the VISTA surveys they provide a view on the Southern Hemisphere from u to K at unprecedented depth and spatial resolution. In addition, the Dutch astronomical community has access to almost 1 year of guaranteed time in the coming ten years.
In this talk I focus on the science being pursued with OmegaCAM in the Netherlands. It includes the Galaxy (ultracompact binaries, stellar streams), galaxy evolution (Local Group, Fornax, Hercules Supercluster) and cosmology (dark matter, dark energy, quasars at extreme redshifts).

10:00, Tucana (ESO HQE, Garching) | ESO Garching
Star and Planet Formation Seminar
Talk — The Jet-Accretion Connection in Young Stellar Objects
Roberto Galvan-Madrid (ESO)

Abstract

I will give an update on a program that we are carrying to test the link between accretion and ejection in young stellar objects (YSOs). The idea is to do time monitoring using tracers of both accretion and ejection of full, nearby star formation regions, therefore including YSOs at each evolutionary stage. The first component of the project is a radio monitoring with the JVLA started in mid 2012. I will show our first results quantifying the radio variability in Corona Australis, which arises from a combination of free-free from radio jets and synchrotron from magnetospheres, depending on the evolutionary stage. I will also show preliminary results of a 0.5x0.5 deg radio mosaic in Ophiucus. The second component of the project is a near-infrared monitoring in the same fields. Although this part initially suffered from several problems, now we are successfully monitoring Corona Australis with the KMOS multi-IFU on the VLT, using lines such as Br Gamma and H_2 in the K band. I will show some preliminary results from the KMOS SV season and ask for advice/help on ancillary NIR observations that we could use.

03/02/14 (Monday)
09:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching

Abstract

Exoplanet research is one of the major science drivers for the future European Extremely Large Telescope (E-ELT). This community workshop will explore the science cases and the planned capabilities of the E-ELT in the field of exoplanet research. The aim is to provide a synthesis of the goals to be achieved by the E-ELT with its planned instrumentation in the field of exoplanets and the most relevant issues in exoplanet science for the next decade. Topics to be discussed include: initial conditions for planet formation; planetary populations determined from detection surveys; characterisation through resolved imaging and direct and transit spectroscopy; the search for habitable planets.

January 2014

30/01/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Cosmological implications of the clustering of galaxies in BOSS
Ariel Sanchez (MPE)
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Abstract

Driven by the potential of large-scale structure (LSS) observations to shed light on the physics behind the accelerated expansion of the Universe, several ground-breaking galaxy surveys are currently under way. These surveys will measure the LSS of the Universe with unprecedented precision, providing new insights not only on the origin of cosmic acceleration, but also on many other important physical parameters. The ongoing Baryon Oscillation Spectroscopic Survey (BOSS) is an example of these new surveys. In this talk I review the cosmological implications of the large-scale galaxy clustering in BOSS, with an emphasis on the problem of cosmic acceleration.

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12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — The mystery of the origin of planets
Barbara Ercolano (LMU)

Abstract

According to the current paradigm, planet formation comes for free together with star formation. However, the detailed physics governing this formation process is quite complex and demands huge efforts on both sides, in theoretical physics as well as in astronomical observations.

Since about two decades, we know that our solar system is not unique, and meanwhile many exoplanets have been found – also thanks to space-based missions like Kepler. Theorists have to use supercomputers to simulate the physical processes, e.g. in the framework of radiative hydrodynamics. Astrophysicist Barbara Ercolano will introduce this modern and fascinating field of astronomy and tell us if there is another earth out there.

29/01/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Flavour and Symmetries
Claudia Hagedorn (TUM)

Abstract

The Standard Model of particle physics has been very successful in describing gauge interactions, however it cannot answer the fundamental questions of the flavour sector: why are there three generations of elementary particles; why do they have the same gauge quantum numbers, but vastly different masses; why is the mass hierarchy among charged fermions much stronger than among neutrinos and why are the quark mixing angles small, while two of the mixing angles in the lepton sector are large and might be described with special mixing patterns. In many extensions of the Standard Model these fundamental questions are also not addressed. Even more, in such extensions additional particles and interactions are present which lead to large flavor violating signals, if the flavor structure is not highly constrained. Flavour symmetries which act on the space of the three generations of particles, very much like the color gauge group SU(3) on the color indices of the quarks, can play the key role in understanding the features of fermion masses and mixing and can help to efficiently suppress flavour violating signals in theories beyond the Standard Model. The focus of this talk is on symmetries and approaches which can explain the observed lepton mixing angles and make predictions for the yet unknown leptonic CP phases.

28/01/14 (Tuesday)
12:30, Fornax (ESO HQ, Garching) | ESO Garching
Lunch Talk
Talk — Extreme (and not so extreme!) gas properties in the center of our Galaxy
Betsy Mills (NRAO)

Abstract

Gas in the central parsecs of our Galaxy is subject to a harsh environment, including the close proximity of a supermassive black hole, supernova remnants, and massive star clusters. By characterizing the molecular gas conditions in this region, we can quantify the effect that the resulting shocks, x-rays, and cosmic rays have on gas properties and eventually star formation in this region. I will present a combination of results from the APEX, VLA, and GBT telescopes which place new limits on the large densities, temperatures, and turbulent line widths found in the molecular gas in the central 100 parsecs. Close to the black hole, we use data from the APEX telescope, to study the gas density in the Circumnuclear disk (CND), finding that it is not stable against tidal disruption. Almost all clumps appear to be transient and unlikely to form stars. We additionally find that reprocessed dust radiation from the central star cluster appears to be contributing to radiative excitation of HCN in the CND, which may lower the gas densities inferred using this molecule. Farther from the black hole, I will present larger scale VLA and GBT surveys of gas temperatures and turbulence in Galactic center clouds, including new detections of a 400 K gas component which may be shock heated, and finally new hints of cooler and less turbulent clumps embedded within these clouds.

23/01/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Simulating galaxy formation: numerical and physical uncertainties
Debora Sijacki (IoA, Cambridge)
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Abstract

Hydrodynamical cosmological simulations are one of the most powerful tools to study the formation and evolution of galaxies in the fully non-linear regime. Despite several recent successes in simulating Milky Way look-alikes, self-consistent, ab-initio models are still a long way off. In In this talk I will review numerical and physical uncertainties plaguing current state-of-the-art cosmological simulations of galaxy formation. I will then present global properties of galaxies as obtained with novel cosmological simulations with the moving mesh code Arepo and discuss which feedback mechanisms are needed to reproduce realistic stellar masses and galaxy morphologies in the present day Universe.

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17/01/14 (Friday)
09:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Workshop — Star and Planet Formation workshop
16/01/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Probing the physical properties of Kuiper Belt Objects
Emannuel Lellouch (Observatoire de Paris)

Abstract

Once thought to be restricted to Pluto, the outskirts of the Solar System beyond Neptune are now known to harbor a collection of small bodies, the Kuiper Belt objects which represent the remnants of planetesimals that formed during the early phases of planetary accretion. With over 1300 known objects, the orbital characterization of this Trans-Neptunian population (TNOs) is now relatively well established, showing several population families (classical, resonant, scattered/detached, Centaurs) of various dynamical origins. The physical characterization of TNOs has also progressed significantly in the last 20 years, with numerous results obtained on their colors (from visible and IR photometry), surface composition (spectroscopy), rotation state and shape (optical light-curves) and binarity (direct imaging). In recent years, new techniques, including thermal radiometry, stellar occultations and high-resolution spectroscopy, have provided access to other fundamental parameters, such as size, mass density, albedo, and thermo-physical properties (i.e. thermal inertia and emissivity), as well as constraints on their atmospheres. Knowing these quantities is necessary not only for a complete characterization ("portrait") of the individual objects, but also, if they can be measured on a sufficiently large sample, to assess possible correlations between physical and orbital characteristics, possibly testifying of physical processes at work within the population (e.g. collisions, surface irradiation, maintenance of volatile ices...). We will discuss recent findings in the field, presenting general results on the population as a whole, as well as on several prominent objects, particularly the dwarf planets (Pluto, Eris, Haumea, and Makemake).

14/01/14 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Dense gas tracers and star formation laws: Multiple transitions of CS in nearby active star-forming galaxies
Zhi-Yu Zhang (UK ATC, Royal Observatory, Edinburgh)

Abstract

In this talk, I will present our surveys of multiple CS transitions (from J=1→0 to 7→6) in nearby active star-forming galaxies, with the JVLA, GBT 100m, IRAM 30m, SMT 10m, and APEX 12m. The sample includes normal spiral galaxies, starburst, and ULIRGs. We find linear correlations between the luminosities of dense gas (L_dense) and IR emission (L_IR) for all CS transitions. These correlations even extend over eight orders of luminosity magnitude down to Galactic dense cores, and are likely tenable for all densities > 10^4 cm−3 , which indicates that star formation is not related to free-fall time scale for the dense molecular gas. For the first time we prove that irrespective of the critical density of a specific transition, dense molecular gas is universally related to star forming activities for self-gravitational bound gas systems.

09/01/14 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Dynamics and Origin of the Milky Way Bulge
Ortwin Gerhard (MPE)
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Abstract

The inner Milky Way is dominated by a box/peanut shaped bulge believed to have formed through disk instability processes. Recent photometric and spectroscopic surveys have greatly increased our understanding of its spatial, kinematic, and metallicity structure. Formation models are broadly consistent with these data, although many aspects still need to be worked out. There appears to be little evidence for a merger-built classical bulge: the Milky Way may have started out as a pure disk galaxy.

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08/01/14 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — What really are the limits on electroweak sparticles from the LHC?
Aoife Bharucha (TUM)

Abstract

Supersymmetry (SUSY) is a theory providing possible solutions to many unanswered questions, such as the nature of dark matter and the hierarchy problem. However, so far none of the supersymmetric partners of the standard model particles (sparticles), predicted by this theory have been seen at colliders. The LHC in particular has been successful in pushing the limits on these sparticles towards the TeV scale, particularly for coloured sparticles. The production of electroweak sparticles is suppressed, and therefore the bounds are much weaker. The LHC experiments interpret their results in terms of simplified models, and the severity of the resulting bounds has resulted in people questioning whether SUSY can really still answer the hierarchy problem. Aoife will present what the bounds on these particles really are, particularly for the case of electroweak sparticles, the lightest of which is a potential candidate for WIMP-like dark matter. Further, Aoife will discuss whether, in the light of these bounds, the original motivations for SUSY are still as persuasive as they were in the pre-LHC era.