Seminars and Colloquia at ESO Garching and on the campus

December 2013

19/12/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Black holes and galaxy evolution: Does AGN activity follow or prevent star formation?
Ryan Hickox (Dartmouth College)
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Abstract

Recent years have seen remarkable advances in our understanding of how supermassive black holes form and grow over cosmic time, and how energy released by active galactic nuclei (AGN) connects the growth of black holes to their host galaxies and large-scale structures. Still a basic and essential question has remained largely unanswered: Does the fueling of AGN activity *follow* along with star formation in galaxies, or does feedback from AGN *prevent* star formation? I will argue that both scenarios take place depending on the properties of the galaxy and its dark matter halo. Specifically, I will review recent results suggesting that the long-term rate of black hole accretion is closely tied to the rate of star formation in the host, so that essentially all star-forming galaxies may be thought of as hosting an AGN after accounting for rapid stochastic variability. I will further discuss the strong evidence that in passive galaxies in massive halos, mechanical feedback from AGN serves to heat gaseous atmospheres and prevent further star formation. These results suggest that the connection between black holes and their host galaxies changes significantly as halos grow and galaxies evolve from star-forming to passive systems.

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18/12/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Search for Supernova Debris in Earth's Microfossil Record
Peter Ludwig (TUM)

Abstract

When a nearby supernova explodes, our solar system is exposed to its ejecta, which can be incorporated into terrestrial geological records. In this talk, Peter will show how accelerator mass spectrometry (AMS) can be used to detect such ejecta in the form of the long-lived radioisotope 60-Fe. After a short introduction including earlier results of 60-Fe measurements, he will show why the fossils of magnetotactic bacteria in ocean sediment are a promising geological reservoir for 60-Fe measurements and present a novel technique for their characterization using magnetic measurements. For this project, two sediment cores from the Eastern Equatorial Pacific are being analyzed. The preliminary AMS results of the first core and the first part of the second core will be presented as well.

17/12/13 (Tuesday)
10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — KMOS observations of candidate high mass young stellar object
Suzanne Ramsay (ESO)

Abstract

This talk will present KMOS observations of a high mass YSO candidate and the outflow(s) associated it. The outflows were discovered as part of a survey to explore the similarities and differences between high and low mass star-formation. Preliminary analysis of the KMOS data will be presented. The potential for this instrument for star-formation studies will be discussed.

13/12/13 (Friday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — A Census of Stellar Mass in 10 Massive Haloes at z~1
Remco van der Burg (Leiden Observatory)

Abstract

One of the main objectives in the field of extragalactic astronomy is to understand the connection between galaxies and the distribution of the underlying dark matter. In order to understand the physics behind baryonic processes that can affect the distribution of dark matter, models need observational constraints. I will present measurements of the stellar mass content of 10 rich clusters in the Gemini Cluster Astrophysics Spectroscopic Survey (GCLASS) around redshift z~1. We find that the stellar mass fraction at fixed halo mass shows no significant evolution towards lower redshift clusters. However, the spatial distribution of stellar mass in these haloes appears to evolve significantly. We measure a relatively high NFW concentration parameter c~7 for the stellar mass distribution in these clusters, and debate a possible scenario to explain the evolution of the stellar mass distribution from the GCLASS sample to their likely descendants at lower redshift.

12/12/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Galaxies as seen through the most energetic explosions in the universe
Sandra Savaglio (MPE)
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Abstract

Gamma-ray bursts (GRBs) are explosions of stars (longer than 2 seconds) or merging compact objects (neutron stars / black holes, shorter than 2 seconds). Although GRBs are the most energetic events after the Big Bang, their detection and localization are still very difficult. Systematic search during the past 17 years led to 330 spectroscopic redshifts; for about half of them, the host galaxy was studied in some detail. Despite the small numbers, their impact on our understanding of galaxies is large. GRB hosts offer the opportunity to explore regions of the universe which are observationally hostile for traditional means, due to gas and dust absorption, or to the large distance. The typical long-GRB host galaxy at low redshift is small, star-forming and metal poor, whereas explorations in recent years at intermediate-redshift have revealed the presence of more massive, dusty and chemically evolved galaxies. Finally, z>5 long-GRB hosts have given so far elusive results, indicating very small galaxies, smaller than what is reachable today with NIR deep surveys. The common factor is the stellar progenitor: in long GRBs these are very massive rare/short-lived stars, present in young regions whose redshift evolution is closely related to the star-formation history of the universe.

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12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — News from the South Pole: Detecting high-energy neutrinos with the IceCube experiment
Elisa Resconi (TUM)

Abstract

The IceCube experiment is one of the biggest and most fascinating detectors in modern physics. Being installed at one of the coldest and most deserted sites of the world directly at the Amundsen-Scott Station at the South Pole, IceCube is built to detect neutrinos, elementary and electrically neutral particles which easily penetrate matter. Neutrinos are produced in the interior of the Earth and the Sun, however, IceCube's task is to catch extragalactic very energetic neutrinos coming - very likely - from supernova remnants and relativistic jets of active galaxies. The detector volume is the ice shield itself which is transparent in depths of 2 to 2.5 km and which is pierced by cables carrying several thousand light detectors. Prof. Dr. Elisa Resconi (TU München) who is a member of the IceCube Collaboration and the Excellence Cluster Universe will present this fascinating project, comment on daily work in an about -50°C surrounding and give a status on the recent discovery of extragalactic neutrinos with IceCube.

12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Talk — Life, the Universe and Everything 
in 42 minutes - A blackboard extravaganza explaining 
what the Universe had to do to make life possible
Joe Liske and Jason Spyromilio (ESO)

Abstract

Quantum fluctuation? Big Bang? Inflation. Expansion. Strong nuclear interaction. Particle-antiparticle annihilation. Deuterium and helium production. Density perturbations. Recombination. Blackbody radiation. Local contraction. Reionization. Biased galaxy formation. Contraction. Ionization. Opaque hydrogen. Massive star formation. Deuterium ignition. Hydrogen fusion. Hydrogen depletion. Core contraction. Envelope expansion. Helium fusion. Carbon, oxygen, and silicon fusion. Iron production. Implosion. Supernova explosion. Metals injection. Star formation. Supernova explosions. Star formation. Planetesimal accretion. Planetary differentiation. Crust solidification. Volatile gas expulsion. Ozone production. Ultraviolet absorption. Photosynthetic unicellular organisms. Oxidation. Mutation. Natural selection and evolution.

11/12/13 (Wednesday)
11:00, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — The SF2 project: linking the Structure Formation process to the evolution of the galaxy Star Formation Activity
Paola Popesso (TUM)

Abstract

Achieving an observational determination and a theoretical understanding of the Cosmic Star Formation History (CSFH) is one of the biggest challenges in the study of galaxy formation and evolution. The most striking feature of the CSFH is that it shows a dramatic drop of an order of magnitude in the last 8 Gyrs to the present day after a rather constant phase of high activity. What caused this dramatic change, is still one of the biggest astrophysical questions. As a matter of fact, the progressive decline of the star formation activity of the Universe in the last 8 Gyrs anti-correlates with the late-time growth in the number density of massive dark matter halos. Thus, it is mandatory to ask if the very same process of assembly and growth of structures may be the main cause or one of the major drivers of the 1 order of magnitude decline in the CSFH. The goal of SF2 project is to measure the contribution of dark matter halos of different masses to the CSFH of the Universe. The final aim is to definitively probe whether the environment is one of the key drivers of the galaxy evolution. In this talk, Paola will present the preliminary results of the project and the future developments.

10/12/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Full spectral fitting techniques: shedding light on unresolved stellar populations
Ivan Katkov (Sternberg Astronomical Institute, Moscow State University)

Abstract

Spectroscopic observations of galaxies provide us with the information about their internal kinematics and stellar populations. Internal kinematics of a galaxy imprints current dynamical state, while stellar population keeps a fossil record of the star formation history that both become crucial for understanding galaxy evolution. I will briefly review data analysis techniques used to extract internal kinematics and properties of unresolved stellar populations. Also I will present our method for simultaneous analysis of spectroscopic and photometric information. The advantages and disadvantages of different techniques will be considered.

06/12/13 (Friday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Probing Dwarf and Dark Galaxies in the Sloan Digital Sky Survey
Lorrie Straka (University of Chicago)

Abstract

Absorption lines from galaxies at intervening redshifts in quasar spectra are sensitive probes of metals and gas that are otherwise invisible due to distance or low surface brightness. However, in order to determine the environments these absorption lines arise in, we must detect these galaxies in emission as well. Galaxies on top of quasars (GOTOQs) are low-z galaxies found intervening with background quasars. These galaxies have been flagged for their narrow galactic emission lines present in quasar spectra in the SDSS.

Typically, the low-z nature of these galaxies allows them to be easily detected in SDSS imaging. However, a number of GOTOQs (about 30%), despite being detected in spectral emission, are NOT seen in SDSS imaging. This implies that they may be dark galaxies, dwarf galaxies, or similarly low surface brightness galaxies. Additionally, about 25% of those detected in imaging are dwarf galaxies according to their L* values. Dwarf galaxies have long been underrepresented in observations compared to theory and are known to have large extents in dark matter.

Given their prevalence here in our sample we must ask what role they play in quasar absorption line systems (QSOALS). Recent detections of 21-cm galaxies with few stars imply that aborted star formation in dark matter sub-halos may produce QSOALS. Thus, this sub-sample of galaxies offers a unique technique for probing dark and dwarf galaxies. The sample and its properties will be discussed, as well as prospects for the future.

05/12/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The Quest for Dark Matter
Gianfranco Bertone (University of Amsterdam)
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Abstract

Astrophysical and cosmological observations provide compelling evidence that about 85% of all the matter in the Universe is in the form of Dark Matter, an elusive substance which is currently searched for with a variety of experimental strategies. In my talk, I will argue that we may be about to witness a pivotal paradigm shift in physics, as we set out to test the existence of some of the most promising dark matter candidates - the so called WIMPs, for Weakly Interacting Massive Particles - with a wide array of experiments, including the Large Hadron Collider at CERN and a new generation of astroparticle experiments underground and in space.

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03/12/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — New Sub-stellar Companions and Stellar Multiplicity in the Taurus Star-Forming Region
Sebastian Daemgen (University of Toronto)

Abstract

Multiple stars are an inevitable, if not necessary outcome of the star-formation process. Their investigation, in particular in young star-forming regions where dynamical processing might not have removed all signatures of the primordial orbital and environmental parameter distributions, puts valuable constraints on the mechanisms at work during the first stages of a (multiple) star's life. In this talk I will present results of a large, coherent survey for sub-stellar companions and stellar multiplicity of the 1Myr-old Taurus star-forming region. Due to our deep sensitivity limit of ~1 MJup and minimum separations of <~20 AU at the distance of Taurus, we detect more than 90 (stellar, brown dwarf, and planetary) companion candidates close to ~50 stars. Follow-up observations were conducted to confirm part of these systems as physically bound. The resulting statistics of the binary frequency, mass ratios, and separations are put into context with recent results from other nearby young star-forming regions to draw conclusions about the processes involved in the formation of stars and planets. For example, it appears that the detected low frequency of brown dwarf companions is consistent with stars and brown dwarfs forming through the same process.

November 2013

28/11/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Constraining galaxy physical properties from multi-wavelength observations: where do we stand?
Stephane Charlot (IAP, Paris)

Abstract

After a brief introduction on galaxy spectral synthesis, I will describe different approaches which have been developed over the past several years to interpret the ultraviolet, optical and infrared emission from galaxies in terms of constraints on physical parameters, such as star formation history, metallicity and dust content. I will emphasize recent progress in constraining the content and spatial distribution of dust from the integrated spectral properties of galaxies. I will also investigate in a quantitative way the relative merits of different types of photometric and spectroscopic observations to constrain galaxy physical parameters. Finally, I will conclude by mentioning some current challenges of the spectral synthesis of galaxies.

27/11/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — The disks of dawn: setting the stage for the formation of planetary systems
Leonardo Testi (ESO)

Abstract

Circumstellar disks appear in the early phases of formation of stars and play a key role in the assembly of the final mass of the central star and in the possible formation of a planetary system around it. Leonardo will review our understanding of the properties and evolution of disks around young stellar objects, focusing on the solids (dust and pebbles) in disk. The evolution of the solids is directly related to the initial stages of planets formation as grains are expected to grow to large pebbles and form first planetesimals and then rocky cores of planets. Leonardo will also discuss the current observational evidence for grain evolution in disks, the difficulties and successes of theoretical models to explain observations and the latest ideas on grain populations segregation in disks. He will discuss future observational tests, in particular with ALMA Early Science and beyond, that will allow us to pose tighter constraints on models of solids evolution in disks.

26/11/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Probing inner NGC 4258: Warped, Unstable and Eccentric?
Elizabeth Humphreys (ESO)

Abstract

Nearby AGN NGC 4258 displays strong 22 GHz water maser emission, which enables mapping of a circumnuclear disk at the 40 000 Schwarzschild radius level (within 1 pc of the supermassive black hole). In this talk, I will discuss how we have used the masers to investigate the Unified Model for AGN. I will also describe how we have used the masers to make a new, high-accuracy geometric distance measurement to the galaxy. With this measurement, we have re-anchored the extragalactic distance scale of Riess et al. (2011) and obtain a Hubble constant of 72.0 ± 3.0 km/s/Mpc.

22/11/13 (Friday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Active Galactic Nuclei: questions about the central engine
Volker Beckmann (Francois Arago Centre, APC, Paris)

Abstract

In a recent text book (Beckmann & Shrader, 2012) we are discussing in depth the status of AGN research, the open questions and possibilities to answer them. In this presentation I will focus on the main open issues concerning the central engine of AGN. Is the central black hole rapidly spinning and can we proof this? What is the dominating accretion mechanism in AGN? Why do some AGN form jets and others don't and how do the jets start off? Is the emission of blazars dominated rather by synchrotron self-Compton or by external Compton processes? I outline the status of related research, formulate the questions and try to hint at research projects able to tackle these fundamental topics.

21/11/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — High energy neutrinos from the Cosmos? Recent results from the IceCube Neutrino Telescope
Elisa Resconi
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Abstract

The neutrino observatory IceCube is opening a new observational window to the Universe. IceCube, which has been fully constructed in the icecap at the South Pole, is taking data since Spring 2011 in full configuration. The first years of data reveled the existence of extremely high neutrinos at the PeV scale. The observed diffuse neutrino flux is with high probability of astrophysical origin. In this talk I will summarize the recent observation and discuss the prospect for point source searches.

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12:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Fruits of the Universe
Talk — The final parsec problem of binary supermassive black holes
Scott Tremaine (Princeton University)

Abstract

Binary supermassive black holes at the centers of galaxies, with orbital separations of a few parsecs, are an inevitable consequence of hierarchical models of galaxy formation. Mergers of such binaries produce strong gravitational wave signals and the detection of these signals is one of the primary goals of the proposed eLISA spacecraft. However, straightforward dynamical estimates imply that the merger time for typical black-hole binaries exceeds the Hubble time. Scott Tremaine will review efforts to solve this "final parsec problem" and why he thinks it is not a problem.

10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — Radio variability and the X-ray-radio connection - a deep JVLA/Chandra view of the Orion Nebula Cluster
Jan Forbrich (University of Vienna)

Abstract

High-energy processes in Young Stellar Objects (YSOs) can be observed both in X-rays and in the centimetric radio wavelength range. While the past decade has brought a lot of progress in the field of X-ray observations of YSOs, (proto)stellar centimetric radio astronomy has only recently begun to catch up with the advent of the newly expanded Karl G. Jansky Very Large Array (JVLA). The enhanced sensitivity is fundamentally improving our understanding of YSO radio properties by providing unprecedented spectral as well as temporal resolution. As a result, it is becoming easier to disentangle coronal-type nonthermal radio emission emanating from the immediate vicinity of YSOs from thermal emission on larger spatial scales, for example ionized material at the base of outflows. Of particular interest is the correlation of the by now relatively well-characterized X-ray flaring variability with nonthermal radio variability. We have observed the Orion Nebula Cluster, a benchmark for X-ray and radio studies of YSOs, in about 24 hours of simultaneous observations using Chandra and the JVLA. Our first results provide new insights into the cluster, highlighting the capabilities of the JVLA for radio continuum observations of YSOs in general.

20/11/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Universe Colloquium: The centenary of the birth of Bruno Pontecorvo: "Bruno Pontecorvo and neutrino"
Samoil Bilenky (TUM)

Abstract

This talk is dedicated to the centenary of the birth of the great neutrino physicists Bruno Pontecorvo. Samoil will discuss a radiochemical method which was proposed by Pontecorvo to detect neutrinos. According to the the myon-electron universality of the weak interaction he was able to prove in an accelerator neutrino experiment that electron neutrino and myon neutrino are different particles. Samoil will discuss Pontecorvo's pioneer idea of neutrino masses, mixing and oscillations in some detail.

19/11/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — The Magnetism of Massive Stars
Veronique Petit (University of Delaware, Newark)

Abstract

Massive star magnetism is often considered an astronomical "wildcard", as it is hard to predict in which stars it may occur. This reflects our fundamental ignorance of the origin of massive star magnetism, and compels us to better understand the scope of its influence on massive stars individually, and also as a population. In the last decade, our understanding of this phenomenon has made a giant leap forward thanks to a new generation of powerful spectropolarimeters capable of measuring the Zeeman effect in the spectra of these stars. Over the past 5 years, ambitious projects such as the Magnetism in Massive Stars (MiMeS) Collaboration have been seeking out magnetic massive stars in the Galaxy, to better understand their origins, physical properties, and how they influence observable stellar characteristics. This presentation will review our current understanding of the impact of magnetism on the lives of the most massive stars.

00:00, Auditorium and Council Room (ESO, Garching) | ESO Garching

Abstract

The aim of the 2013 ALMA Community Days is to optimally prepare the astronomical community for ALMA Cycle 2 proposal submission. Besides a series of technical and scientific presentations, there will also be practical hands-on tutorials for the ALMA proposal preparation software, and an introduction to (sub)mm-interferometry techniques for novices in the field.

14/11/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The Gaseous Environments of High-Redshift Galaxies: The CGM and ISM of Star-Forming Systems 2<z<3
Gwen Rudie (Carnegie-Princeton Fellow)
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Abstract

The gaseous component of galaxies is a crucial but poorly-constrained aspect of galaxy formation and evolution. I will present results from the Keck Baryonic Structure Survey (KBSS), a unique spectroscopic survey designed to explore both the physical properties of high-redshift galaxies and the connection between these galaxies and their surrounding intergalactic baryons. The KBSS is optimized to trace the cosmic peak of star formation (z~2-3), combining Keck/HIRES spectra of 15 hyperluminous QSOs with densely-sampled galaxy redshift surveys surrounding each QSO sightline. I will characterize the physical properties of the CGM gas through the spatial distribution, column densities, kinematics, and absorber line widths of ~6000 HI absorbers surrounding ~900 foreground star-forming galaxies within 50 kpc to 3 Mpc of a sightline. These measurements provide clear evidence of gas inflow and outflow as well as accretion shocks or hot outflows from these forming galaxies. I will compare these observations with recent theoretical predictions, highlighting discrepancies that suggest our theoretical picture of gas flows into and out of galaxies is still incomplete. I will also discuss KBSS-MOSFIRE, a rest-frame optical spectroscopic survey of galaxies in these same QSO fields. These data provide new insight into the physical properties of HII regions within these star-forming systems.

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13/11/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Low-mass dileptons: A thermometer for the hottest stuff in the universe
Torsten Dahms (TUM)

Abstract

The goal of ultra-relativistic heavy-ion collisions at RHIC and the LHC is to study the properties of the quark-gluon plasma (QGP), a phase of matter with partonic degrees of freedom. Electromagnetic radiation, in form of photons or lepton pairs, is a penetrating probe that allows the investigation of the full time evolution and dynamics of the produced matter, as it does not undergo strong interaction in the final state. The dilepton spectrum is extremely rich in physics sources: Thermal black-body radiation is of particular interest as it carries information about the QGP temperature. Modification of the spectral function of light vector mesons are linked to the potential restoration of chiral symmetry in the QGP phase. Correlated lepton pairs from semi-leptonic charm and beauty decays provide additional information about the heavy-quark energy loss. Finally, the suppression of quarkonia in the QGP give access to an independent temperature measurement. In this talk, dilepton results from RHIC will be reviewed and an outlook for possible low-mass dilepton measurements at the LHC will be given.

12/11/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Disk galaxy evolution since z=1
Asmus Boehm (Institute for Astro- and Particle Physics, Innsbruck)

Abstract

Disk galaxies play a fundamental role for our understanding of the now generally adopted cosmology according to which the Universe is dominated by Dark Energy and Dark Matter. An important tool to test predictions of simulations based on this concordance cosmology are so-called scaling relations that link fundamental parameters of disks like rotation velocity and luminosity (-> Tully-Fisher Relation) or rotation velocity and size. Using deep spectroscopy with the Very Large Telescope and imaging with the Hubble Space Telescope, we have constructed a data set of several hundred disk galaxies that span more than half the age of the Universe and a variety of environments. With this sample, utilizing scaling relations like the Tully-Fisher, I will show how the disk galaxy population evolved over the past 8 Gyr, how stellar population properties relate to galaxy masses, and how transformations between different galaxy types might occur in galaxy clusters.

08/11/13 (Friday)
10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — Determining the gas and dust structure of the transition disk HD 135344B (SAO 206462)
Andres Carmona (IPAG, Grenoble)

Abstract

Transition disks are protoplanetary disks displaying an inner dust cavity. The origin of these cavities is
currently under debate. One exciting possibility is that they might be related to planet formation.
HD 135344B is a F4V star with a transition disk that has been observed at multiple wavelengths
with a diversity of  techniques (imaging, interferometry, spectroscopy) tracing its dust and gas contents.
The disk of HD 135344B has the remarkable property of displaying emission of warm CO gas at 4.7 micron
inside the 45 AU dust gap imaged in the sub-mm. HD 135344B is also an object in which Herschel has detected
[OI] emission at 63 micron. In this talk, I will discuss how the simultaneous radiative transfer modeling of
multi-wavelength/multi-instrument gas and dust observations has allowed us to constrain the structure of
the transition disk around HD 135344B, and the connection that this structure might have with planet formation.

07/11/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Testing Gravity with Cosmology: a new Golden Age?
Pedro Ferreira (University of Oxford)
06/11/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — A brief history of computational astrophysics
David Hubber (University of Sheffield)

Abstract

The scientific method traditionally involves a cyclic process of developing predictive theories and performing falsifying experiments to better understand physical phenomena. However, astrophysics is a field where direct experiments are almost impossible and even observing natural phenomena at a distance is often impractical due to technical challenges and the extremely long time scales (up to billions of years). This has resulted in numerical experiments, i.e. computer simulations, becoming an important tool in testing and falsifying theories in place of real-world experiments. We discuss the history and development of the numerical experiment in astrophysics from its beginnings in the mid-20th century to the present day and how it has been used in various fields of astronomy like star formation, galaxy evolution and cosmology to solve key problems. We will also discuss some of its drawbacks, how its role has evolved and how it has influenced the scientific method in astronomy today.

05/11/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — SN IA in the IR: RAISINs trace cosmic expansion best
Robert P. Kirshner (Harvard University)

Abstract

Recent work shows that SN Ia are better standard candles in the near IR than at optical wavelengths. Even better, the vexing problem of dealing with dust absorption and intrinsic color variations is simpler in the IR. In the past year, we have used PanSTARRS to discover 24 supernovae at 0.2

October 2013

31/10/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Early-type galaxies: the last 10 billion years
Sugata Kaviraj (Oxford University, UK)
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Abstract

I review our current understanding of the formation of early-type galaxies (ETGs), in the context of studies that exploit rest-frame UV-optical photometry. I show that, contrary to our classical notion of them being old and passively evolving, ETGs host widespread star formation at late epochs via persistent minor merging, which contributes 20% of their stellar mass at the present day. Similarly, while our traditional view has been that ETGs are remnants of gas-rich major mergers at high redshift, I present empirical evidence that argues against major mergers as the dominant mechanism for the formation of these systems in the early Universe. Notwithstanding their apparent homogeneity today, ETGs are a rather heterogeneous population of galaxies, in which early mass growth was likely driven either by direct accretion (‘cold flows’) or minor mergers at high redshift.

Video

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29/10/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — De revolutionibus orbium galacticum: Angular momentum in spiral galaxies
Danail Obreschkow (ICRAR, Perth, Australia)

Abstract

The concept of angular momentum in galaxies is about to penetrate mainstream astronomy thanks to phenomenal progress in integral field spectroscopy and supercomputing capabilities. This talk presents high-precision measurements of the specific baryon angular momentum, contained in stars, atomic gas, and molecular gas, in 16 nearby late-type galaxies of the THINGS sample. A strong, irreducible correlation is found between mass, angular momentum, and morphology traced by the bulge mass fraction. I will discuss the origin of this relation using geometrical scaling relations coupled with stability considerations. I will also discuss how mass and angular momentum link to classical empirical relations, such as the fundamental plane for spiral galaxies, the Tully-Fisher relation, and the mass-size relation. These results advocate the regular use of angular momentum in classifying and modelling galaxies.

24/10/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Imaging of Protoplanetary disks at mm/submm wavelengths
Anne Dutrey (Laboratoire d'Astrophysique de Bordeaux)

Abstract

Planetary formation, which is expected to occur in protoplanetary disks orbiting around young low-mass stars, is a major challenge of modern astrophysics. Since the last ten years, the gas and dust content of protoplanetary disks have been intensively observed using mm/submm arrays. The analysis of these observations revealed the complexity of the disk physics and chemistry. In 2011, ALMA started to operate and opened a new era, thanks to its high sensitivity and resolving power. In this evolving context, I will present some recent high angular, high sensitivity observations obtained with the IRAM array and ALMA. I will discuss the gas (mostly CO) and dust properties on a few prototypical objects such as DM Tauri, GG Tauri or AB Auriga.

23/10/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — An introduction to Black Hole Astrophysics
Andreas Mueller (TUM)

Abstract

This talk will be a review on black hole astrophysics to non-experts including black holes as solutions of the Einstein equation in General Relativity, curvature singularities, black hole formation and accretion as well as astronomical detection methods for black holes. We will also discuss the phenomenon of mini black holes in particle accelerators and black-hole-like solutions found in the framework of pseudo-complex General Relativity.

22/10/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Where do stars form at high redshift? Results from Herschel and Planck
Matthieu Béthermin (ESO)

Abstract

The thermal infrared domain (8-1000 microns) contains half of the relic light emitted during structure formation. This emission is mainly caused by dust heated by young stars in star-forming galaxies at high redshift and called Cosmic Infrared Background (CIB). Identifying and characterizing the objects responsible for this emission is thus crucial to built a consistent picture of star formation in the Universe.

Thanks to its very good sensitivity, Herschel allows to resolve directly the CIB into individual sources in the far-infrared, and obtain some statistical constraints on these objects in the sub-millimeter. These observations showed a "main-sequence" of star-forming galaxies (i.e. a strong correlation between star formation rate and stellar mass). Starting from observed “main sequence” of star-forming galaxies and adding a population of merger-driven starburst, we managed to reproduce the galaxy number counts from mid-IR to the radio.

We then extended our model to clustering measurements (CIB fluctuations, angular correlation function of resolved galaxies), using the correlation between the stellar mass and the halo mass of galaxies. This model well agrees with the measurements of auto- and cross-power spectrum of the CIB anisotropies measured by Planck, Herschel, SPT and ACT, but also the CIBxCMB lensing signal detected by Planck. This model predicts that star formation efficiency is maximal for a mass of 10^12 Msun at all redshift. If we take into account the halo growth, this implies that CIB is dominated by galaxies in future clusters (log(M)>13.5 Msun at z=0) at z>5, of groups (12.5

21/10/13 (Monday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Pollution by early stellar disk accretion: a new model to explain multiple stellar populations in globular clusters
Henny J.G.L.M. Lamers (Utrecht University and University of Amsterdam)

Abstract

Globular clusters were once thought to be simple stellar populations. However, in recent year it has become clear that each cluster contains different populations with specific abundance patterns. The most striking ones are multiple main sequences (indicating different He-abundances), the Na-O anti-correlation and the Mg-Al anti-correlation.

This has been interpreted as a sign that each cluster had several episodes of star formation, i.e. multiple generations, where each new generation is formed from mass ejected by evolved stars. The proposed polluters are: AGB stars, rapidly rotating massive stars, and interacting massive binaries. This interpretation has several serious problems: a mass budget problem, a gas-retention problem, an IMF problem and a Li-problem.

I will briefly discuss the observations and the models with their specific problems and uncertainties. I then suggest a new model in which the observations are explained by one single star forming event with the low mass stars polluted by ejecta from the massive stars of the same event. This model overcomes some of the serious shortcomings of the multiple generation models. I will discuss uncertainties of this model, and possible observational tests. (reference: Bastian et al. 2013, arXiv1309.3566)

18/10/13 (Friday)
13:00, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Spin tracking for Geometric phase correction for EDM searches with ultracold neutrons
Albert Steyerl (Univ. of Rhode Island)

Abstract

Pendlebury et al. [Phys. Rev. A 70, 032102 (2004)] were the first to investigate the possibility that the search for an electric dipole moment of elementary particles based on Ramsey-separated oscillatory field magnetic resonance with trapped ultracold neutrons may be affected by a false EDM signal related to geometric phases. Their work was based on the Bloch equation and later work using the Redfield method corroborated their results. Employing a third method, direct solution of the spin-dependent Schroedinger equation, we obtain more general analytic expressions for a specific geometry. They reduce to the previous results where comparison is possible, showing that all three methods are equivalent. As a new application we analyze the effect of path curvature due to the Coriolis acceleration.
17/10/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Asteroseismology of stellar populations in the Milky Way
Andrea Miglio (University of Birmingham)

Abstract

The Milky Way provides a unique opportunity to study in detail how a giant spiral galaxy is assembled and how it evolves. Our current understanding of Galactic formation and evolution is severely hampered by a lack of precise observations of basic stellar properties such as distances, masses, and ages. GAIA will shortly overcome current limitations associated with estimating distances to stars, however, accurate age determination of individual field stars will still be a major obstacle to our understanding the Milky Way. Asteroseismology provides the way forward.

Average seismic constraints now available for thousands of G-K giants with CoRoT and Kepler make possible the accurate and precise determination of stellar radii and masses. We argue that G-K giants showing solar-like oscillations represent a new class of accurate distance indicators. Thanks to CoRoT and Kepler observations we can now map the position of thousands of stars in different regions of the Milky Way. Moreover, since the ages of stars on the red-giant branch are primarily a function of their mass, the availability of seismic constraints makes G-K giants precise age indicators. To improve the accuracy of age estimates thorough tests of stellar models need to be carried out. I will discuss how a combination of seismic and spectroscopic constraints can help in this respect.

16/10/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — A string theory road to the (supersymmetric) Standard Model
Patrick Vaudrevange (TUM)

Abstract

In this talk we follow a road of high-energy particle physics which brings us to physics beyond the Standard Model (e.g. Grand Unified Theories and Supersymmetry) and ends in extra dimensions and string theory. In detail, we focus on the compactification of heterotic string theory on six-dimensional compact spaces (i.e. orbifolds) and discuss some generic phenomenological properties like discrete (R- and non-R-) symmetries.

15/10/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Accretion Variability in Young Stellar Objects
Gráinne Costigan (Institute of Advanced Studies, Armagh Observatory; ESO Garching)

Abstract

Accretion is one of the dominant sources of radiation from a low mass young stellar object for the first few million years. This process regulates the flow of material and angular momentum from the surroundings to the central object, and is thought to play an important role in the definition of the long term stellar properties. Variability is a well documented attribute of accretion, and has been observed on time-scales ranging from days to years.

My thesis set out to use the intrinsic accretion variability to probe the inner regions of these systems. Two spectroscopic surveys were utilised that concentrated on the H-alpha emission line, which is known to be closely connected to the accretion process. Together, these surveys covered 24 object including low mass T Tauri, intermediate mass T Tauri stars and Herbig Ae stars, on time-scales of minutes, days, weeks, months to years. These two studies found the accretion variations to be less than half an order of magnitude and dominated by time-scales close to the rotation period. A further photometric monitoring campaign was undertaken to confirm the short term variations found in the low mass sample.  
I will present the results of these studies, and argue that they imply that the majority of the variations in typical accreting objects are the result of an asymmetric accretion flow. 
10/10/13 (Thursday)
16:15, MPA Large Seminar Room E.0.11 (MPA, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — What the population tells us
Simon Lilly (ETH Zurich)

Abstract

The large extragalactic surveys, exemplified by SDSS locally and by the deep surveys such as COSMOS at high redshifts (in which the VLT has played a major role) have opened up new avenues in the study of galaxy evolution by enabling us to study the "population" as a whole. I will discuss a number of new insights that have come from taking this new approach. These are based on identifying a limited number of rather striking simplicities, or symmetries, of the population and exploring analytically the implications of these. I will talk specifically about the formation of passive "quenched" galaxies, the control of star-formation in the normal star-forming population, the relative importance of "in situ'' star-formation and merging in building up galaxies. I will end by showing that a high degree of convergence is emerging between different phenomenological approaches to the evolution of galaxies.

08/10/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Interstellar Extinction and Dust Properties - Modelling in a clumpy ISM
Peter Scicluna (ESO)

Abstract

Interstellar extinction is a key method by which we study the dust content of the universe. A correct interpretation of extinction therefore depends upon our understanding of systematic effects. I will briefly review extinction, highlighting the potential for geometry- and resolution-dependent effects to introduce important systematics. I will follow by introducing the numerical techniques we used to investigate and quantify these effects. The results of a number of radiative-transfer simulations will be presented, quantifying the impact of unresolved clumpyness on the observed extinction curve both toward embedded objects and in the diffuse ISM. These models show that changes in the geometrical distribution of the dust can cause significant changes in the shape of the extinction curve, and hence the extinction curve is not a robust probe of the properties of dust in the ISM.

10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — Herschel observations of outer solar system
Esa Vilenus (MPE)

Abstract

Trans-Neptunian objects (TNOs) are remnants of planet formation. They are among the most unprocessed objects in our solar system and are analogs to large bodies which may be the sources of dust in debris disks observed around other strars. Since the first discovery more than twenty years ago about 1500 TNOs are now known but their basic physical properties have been challenging to measure. These properties, such as sizes and albedos of different dynamical groups, are needed in testing models of solar system evolution. Herschel Space Observatory open time key programme "TNOs are Cool" observed a sample of 130 TNOs. In this talk I present sample analysis of the most numerous dynamical class, the classical Kuiper belt objects, which is divided into a dynamically excited population and a dynamically cold component, which possess different sample properties. The surfaces of TNOs have varying albedos from below 3% to almost 100%. The measured size distributions are compatible with the hypothesis that the dynamically cold population formed in a region of the protoplanetary disc where the surface mass density was lower compared to other dynamical groups. The number of binaries among the cold population is high. The bulk mass densities of TNOs with measured size and mass show a decreasing ice/rock ratio as a function of size.

07/10/13 (Monday)
09:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching

Abstract

Jointly organised by the Network for UV Astronomy (NUVA), ESO and the IAG Brazil, this workshop will focus on efficient exploration from the ground of the UV spectrum region. New UV instrumentation, such as CUBES - a joint ESO-Brazil high-resolution UV spectrograph - being planned for the VLT, will open up observation of UV spectral features. The present and future of the field and, in particular, the scientific case of CUBES, will be discussed. Further details are available here or please contact uvastro@eso.org for more information. The registration deadline is 9 September 2013.

01/10/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — The Evolved-Star Dust Budget in Nearby Galaxies
Sundar Srinivasan (ASIAA, Taiwan)

Abstract

The injection of metal-rich material from dusty red supergiants (RSGs) and asymptotic giant branch (AGB) stars drives the chemical evolution of galaxies and the formation of the next generation of stars. It is therefore critical to constrain the dust budget from these evolved objects. For this purpose, we constructed the Grid of RSG and AGB ModelS (GRAMS, Sargent et al. 2011, Srinivasan et al. 2011), which we subsequently used to fit the multi-wavelength information for RSG and AGB candidates in the Magellanic Clouds obtained from the SAGE (Surveying the Agents of Galaxy Evolution, Meixner et al. 2006) survey. The results for the Large Magellanic Cloud (Riebel et al. 2012) show that the cumulative dust ejection rate is much smaller than that needed to explain the current dust mass in the interstellar medium (ISM). We also find a similar result for the Small Cloud (Boyer et al. 2012, Srinivasan et al. in prep).
In this talk, I will provide a brief introduction to the field of dusty AGB stars and summarize our work on the AGB dust return in nearby galaxies. If time permits, I will also discuss a possible solution to the "missing dust" problem.

September 2013

26/09/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The formation and evolution of the galaxy population
Simon White (MPA)
Download video |

Abstract

Recent observations of the high-redshift universe have characterized
the initial conditions for nonlinear structure formation over the full
range of scales responsible for dwarf and giant galaxies, galaxy
clusters and the large-scale cosmic web. At the same time, wide-field
spectroscopic and photometric surveys have measured the abundance and
clustering of low-redshift galaxies as a function of mass, size,
morphology, kinematic structure, gas content, metallicity, star
formation rate and nuclear activity, while deep surveys have explored
the evolution of several of these distributions to z>3.  Galaxy
population simulations aim to interpret these observations within the
LCDM structure formation paradigm, thereby constraining the complex,
diverse and heavily interconnected astrophysics of galaxy formation. I
will show that recent simulations are broadly consistent with the
galaxy abundances and clustering seen in both wide-field and deep
surveys, Such simulations provide predictions for topics as different
as galaxy-galaxy lensing, the triggering and duty cycles of AGN, and
the evolution of Tully-Fisher, mass-size and mass-metallicity
relations. They show galaxy assembly histories to be strongly
constrained by the structure formation paradigm, giving insight into
issues such as internally versus externally driven evolution, inflow
versus winds, major versus minor mergers, in situ versus ex situ star
formation, and disks versus bulges. In addition, simulations can now
be adapted to represent any chosen LCDM-like cosmology, allowing a
first assessment of whether galaxy formation uncertainties will limit
our ability to do precision cosmology with galaxy surveys.

Video

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24/09/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — The state and the mass of H2 in star-forming systems: a new emerging view in the age of ALMA
Padelis Papadopoulos (Cardiff University, UK)

Abstract

I will review standard views about the energy sources of the molecular gas in galaxies, and their impact on H2 gas mass estimates. I will then present a new picture currently being assembled from analysis of Herschel/FTS data and a large CO, 13CO, and HCN ground-bases survey of Luminous Infrared Galaxies with the JCMT and the IRAM 30-m telescope. Finally I will briefly discuss some implications regarding the Xco factor and the so-called bimodal star formation in mergers and disks.

10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — Herschel far-infrared observations of the Carina Nebula Complex
Veronica Roccatagliata (LMU)

Abstract

The star formation process in large clusters/associations can be strongly influenced by the feedback from high mass stars. Whether the resulting net effect of the feedback is predominantly negative (cloud dispersal) or positive (triggering of star formation due to cloud compression) is still an open question. The Carina Nebula complex (CNC) represents one of the most massive star-forming regions in our Galaxy. We have performed a 9 square-degrees Herschel far-infrared survey of the CNC. We discovered about 600 objects that are independently detected as point-like sources in at least two of the five Herschel bands. The star formation rate of the CNC is about 0.017 solar masses per year.  We studied also the properties of the clouds over the entire CNC. Our Herschel maps resolve, for the first time, the small-scale structure of the dense clouds over the entire spatial extent of the CNC. Several particularly interesting regions, including the prominent pillars south of eta Car, are analyzed in detail. The spatial distribution of the Herschel young stellar object (YSO) candidates is highly inhomogeneous and does not follow the distribution of the cloud mass: most Herschel YSO candidates are found at the irradiated edges of clouds and pillars. The currently ongoing star formation process forms only low-mass and intermediate-mass stars, but no massive stars. The density and temperature structure of the clouds reveal that most parts of the CNC are dominated by the strong feedback from the numerous massive stars, rather than random turbulence. Comparing the cloud mass and the star formation rate derived for the CNC to other Galactic star forming regions suggests that the CNC is forming stars very efficiently.

20/09/13 (Friday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — News from the Australian SKA site
Lister Staveley-Smith (ICRAR/CAASTRO/UWA)

Abstract

The first of the Square Kilometre Array (SKA) precursor telescopes in Western Australia is now operational. The first data was taken on August 5 for the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, for which I am PI. Deep EOR observations are also underway. The second precursor, the Australian SKA Pathfinder (ASKAP) begins early science operations in 2015, and full operations shortly after. I will give an update on both of these projects and discuss progress with the international SKA project.
19/09/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Are planetary systems flat?
Scott Tremaine (Institute for Advanced Study)
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Abstract

Laplace argued, correctly, that the small inclinations of planetary orbits implied that the solar system formed from a flat disk. The observational and theoretical evidence on whether extrasolar planetary systems are flat, however, is still ambiguous. I will discuss constraints on flatness from the Kepler spacecraft and other sources; measurements of the Rossiter-McLaughlin effect in transiting planets, which show that many planetary systems have large stellar obliquities, and disk and high-eccentricity migration as competing mechanisms for the formation of hot Jupiters.

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17/09/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — The initial mass function in stellar systems: new method and new estimates
Nikolay Podorvanyuk (Sternberg Astronomical Institute, Moscow)

Abstract

We present the novel technique for the determination of the low-mass end slope of the present day stellar mass function (PDMF) of unresolved stellar populations using pixel fitting of spectra integrated along the line of sight. In stellar systems with long dynamical relaxation timescales, where one can neglect the effects of the dynamical evolution, the PDMF is identical to the IMF at low masses. Our method achieves precision of ~0.1 in MF slope value and hence outperforms classical IMF determination techniques which use direct star counts in open clusters and HII associations. We used our method to obtain IMF for a few GCs and UCDs and 3000 giant elliptical galaxies. We do not see any evidence that the low mass IMF slope in giant ellipticals depends on their mass.

12/09/13 (Thursday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Radiation and outflow Feedback from forming massive protostars
Michael Smith (University of Kent, UK)

Abstract

As a massive protostar forms it is expected to go through phases dominated by Outflow and Radiation. In this talk, it will be explored if these two phases can overlap.
This is achieved through the construction of  an evolutionary scheme which tracks protostellar structure, the environment, the inflow and the radiation feedback.  We investigate constant, decelerating and accelerating accretion rate scenarios and consider both hot and cold accretion, identified with spherical free-fall and disk accretion, respectively. We find that neither spherical nor disk accretion can explain the high radio luminosities of many protostars. Nevertheless, we discover a solution in which the extreme ultraviolet flux needed to explain the radio emission is produced if the accretion flow is via free-fall on to hot spots covering less than 20% of the surface area. Moreover, the protostar must be compact, and so has formed through cold accretion. This adds support to the models in which  massive  stars form via gas accretion through disks which, in the phase before the star bloats, download their mass via magnetic flux tubes on to the protostar.

10/09/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — ALMA's view of one of the nearest starburst galaxies
Alberto D. Bolatto (University of Maryland)

Abstract

In the context of galaxy evolution, it is particularly interesting to understand better the mechanisms that regulate starburst activity in galaxies. In this talk I will present an analysis of the molecular ISM properties in the prototypical circumnuclear starburst galaxy, NGC 253, derived from ALMA observations. I will discuss the evidence for a molecular superwind, our measurements of the mass loss rate, and the possible gas entraining mechanisms. I will show our measurement of the properties of giant molecular clouds in the starburst, in an effort to better understand the conditions in the starburst. Finally, I will present and discuss some of the chemical complexity we see in the data. This extremely rich spectroscopy, a common feature in many ALMA datasets, opens new windows for the study of physical conditions in extragalactic systems.

03/09/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Modelling IR SED of AGN with Spitzer and Herschel data
Anna Feltre (ESO)

Abstract

One of the remaining open issues in the context of the analysis of Active Galactic Nuclei (AGN) is the evidence that nuclear gravitational accretion is often accompanied by a concurrent starburst (SB) activity. What is, in this picture, the role played by the obscuring dust around the nucleus? Can the IR data provided by Spitzer and Herschel help us in extensively investigate both phenomena? Does the presence of an AGN have an impact in the mid- and far- IR properties of galaxies? 
In this talk I will present our contribution to the efforts of answering these questions. I will first show the results coming from a comparative study of various AGN SED modelling approaches, focusing mostly on the much-debated issue about the morphology of the dust distribution in the toroidal structure surrounding the AGN. With the aim of investigating simultaneously the physical properties of active galaxies and coexisting starbursts we developed a multi-component SED fitting tool. I will then present the main results obtained by applying this procedure to a large sample of extragalactic sources representing the Herschel/Multi-tiered Extragalactic Survey (HerMES) population with IRS spectra and with a plethora of multi-wavelength data (SDSS, Spitzer and Herschel/SPIRE).

July 2013

30/07/13 (Tuesday)
10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — High resolution transmission spectrum of Earth’s atmosphere - Seeing Earth as an exoplanet using a lunar eclipse
Fei Yan (ESO)

Abstract

With the fast development in the exoplanet field, more and more terrestrial exoplanets have been detected.  It is of great astrophysical interests and importance to study their atmospheres in the near future. Observing our own Earth's atmosphere provides valuable insights into future exo-Earth atmosphere characterisation. I'll talk about our observation of the Earth’s atmosphere during the total lunar eclipsing of December 10, 2011. The high resolution and high SNR transmission spectrum obtained from this observation will be presented. From the spectrum we detected O2, ozone, water vapour, NO2 and oxygen dimmer. The Ring Effect in strong Fraunhofer lines is observed and we believe it's due to the Raman scattering in the forward-scattered sunlight reflected from the Moon.  We also built an atmospheric spectrum model to fit the observed spectrum, and the column densities of the atmosphere species are calculated.

 

24/07/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Inflation, infinity, equilibrium and the observable Universe
Andreas Albrecht (Univ. of California at Davis)
23/07/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Late-type eclipsing binaries in the LMC: Improving the distance scale, and gaining unique insights about Cepheid variables
Wolfgang Gieren (Univ. Concepcion, Chile)

Abstract

The Cepheid method to determine distances to spiral galaxies, and its
principal sources of systematic error is reviewed. I will report on
recent work of our Araucaria Project group to reduce the most serious
source of uncertainty of the method, the distance to the Large
Magellanic Cloud, to 2% using late-type eclipsing binaries. We have
discovered a number of such systems which contain Cepheid variables
and present a unique opportunity to derive the physical parameters
of the Cepheids with unprecedented accuracy. I will show that this
has led to the resolution of the long-standing Cepheid mass discrepancy
problem. Finally, I will report on a very recent accurate determination
of the distance to the Triangulum galaxy M33 from infrared photometry
of Cepheid variables, and show that the value of the Hubble constant
based on our accurate LMC distance from eclipsing binaries might be consistent,
within the respective 1 sigma errors, with the recent Ho determination
from the Planck satellite.
10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — The Earliest Circumstellar Disks and the Variable Young Stellar Objects Survey
Hsin-Fang Chiang (IFA, University of Hawaii)

Abstract

My talk will include two parts.  First I will talk about interferometric observations and modeling of embedded young stellar objects.  Protostars are surrounded by their natal envelopes in the early stage, while the earliest disks form inside the envelopes.  With radiative transfer modeling and Bayesian statistics, we study the envelope properties and constrain the embedded circumstellar disk.  Then I will introduce the Variable Young Stellar Objects Survey (VYSOS) project, which consists of two new robotic telescopes dedicated to monitor nearby star forming regions in the optical wavelengths.  Observations of VYSOS have started in search of new eruptive events around young stars such as FUor and EXor outbursts.


22/07/13 (Monday)
10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — Star Formation in Massive Clusters: The Outstanding Cases of the Eagle Nebula and CygOB2
Mario Guarcello (Harvard-Smithsonian CfA)

Abstract

Massive stars in young clusters play a key role in the formation and evolution of low mass stars, circumstellar disks and planetary systems. Important feedback provided by the massive stars on the star formation process are the externally induced photoevaporation of nearby circumstellar disks, the dispersing of the surrounding cloud, and the triggering of new star formation events. A deep comprehension of these processes are crucial for the understanding of what environments in our Galaxy are suitable for planet formation. Given their proximity to our Sun, and they rich population of massive and young low-mass stars, the Eagle Nebula (M16) and the Cygnus OB2 association represent ideal targets to study these processes.  I will present the results of deep and detailed multiwavelength study of the young population of M16 and CygOB2, where evidence of the feedback from the massive stars on the star formation process has been found.


18/07/13 (Thursday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Talk — What a snow-capped volcano can tell us about the site quality of Paranal
Reinhard Hanuschik (ESO Garching)

Abstract

Ever checked the skyline towards the East when you were on the Paranal platform? Likely that you then spotted snow in the desert, in form of Llullaillaco. This volcano, at 6739m altitude, is Chile’s third-highest peak.

The line of sight from Paranal towards that summit spans 190km. This provokes the interesting questions: Why is this mountain visible at all, and what does it tell us about the quality of Paranal's atmosphere?

Reinhard will cover aspects of geometry and atmospheric physics, spiced with some sightseeing, archaeology and some words of Quechua. Please join him on his trip to the snow in the desert.

16/07/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — A recurrent nova model for the circumstellar medium around Type Ia Supernovae
Richard Booth (Oxford University, UK)

Abstract

Observational evidence suggests that a significant fraction of Type Ia Supernovae progenitors shape their environment prior to explosion. The circumstellar medium expected from different progenitor models may provide a way to differentiate between the channels. A model for the circumstellar medium as shaped by a recurrent nova is presented and compared with observations. The model shows good agreement with observations of the galactic recurrent nova RS Ophiuchi and is discussed in terms of the observations of Type Ia Supernovae.

12/07/13 (Friday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Chasing disk dispersal indicators: The origin of the [OI] low-velocity component from young stellar objects
Elisabetta Rigliaco (University of Arizona)

Abstract

The formation time, masses, and location of planets are strongly impacted by the physical mechanisms that disperse protoplanetary disks and the timescale over which protoplanetary material is cleared out. Accretion of matter onto the central star, protostellar winds/jets, magnetic disk winds, and photoevaporative winds operate concurrently. Hence, disentangling their relative contribution to disk dispersal requires identifying diagnostics that trace different star-disk environments.

In this talk, I will analyze the low velocity component (LVC) of the Oxygen optical forbidden lines from a large sample of protoplanetary disks and compare this diagnostic with other disk dispersal indicators. Our results suggest that the [OI] LVC traces the disk layer where OH is photodissociated by stellar FUV photons. Part of that layer is gravitationally unbound and leaves the star/disk system in the form of a wind. I will discuss the origin of these winds in the framework of theoretical predictions for magnetically driven and photoevaporative winds.

10/07/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Interactions between strange and plain matter
Kirill Lapidus (TUM)
09/07/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Structural and stellar population evolution of massive cluster galaxies over the past 10 billion years
Alessandro Rettura (Caltech)

Abstract

Small temperature and density fluctuations in the early Universe
have grown into the cosmic web of dark matter and barionic matter
that we see today.  Matter is distributed among large-scale filaments,
punctuated by galaxy clusters at the intersection points of this
web.  Mapping the cosmic history of rich galaxy clusters provides
fundamental information about both cosmology and galaxy formation.
I will describe our panchromatic studies of X-ray and infrared-selected
galaxy clusters and groups at high redshift.  These studies enable
us to trace the first stages of galaxy evolution in high density
environments.  In this talk, I will discuss the role of the environment
on both the structural properties and stellar populations in massive
galaxies in rich, high-redshift environments.

04/07/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — A New View of the High Energy Sky From The Nuclear Spectroscopic Telescope Array (NuSTAR)
Fiona Harrison (Caltech)
Download video |

Abstract

The Nuclear Spectroscopic Telescope Array, the first focusing
high-energy X-ray telescope in orbit, extends sensitive X-ray
observations of the sky from 3 - 79 keV, well above the band pass
where Chandra and XMM-Newton operate.  With an unprecedented
combination of sensitivity, spectral and imaging resolution, NuSTAR is
advancing our understanding of black holes, neutron stars, and
supernova remnants.  I will describe the mission, and present
highlights of science results from the first six months of science
observations.

Video

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03/07/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Discovery of a north/south asymmetry in the distribution of local stars and its implications
Susan Gardner (Univ. Kentucky, USA)
02/07/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Gravitationally lensed dusty star-forming galaxies from the South Pole Telescope
Carlos De Breuck (ESO)

Abstract

We have a selected a sample of over 100 gravitationally lensed dusty star forming galaxies from the 2500 square degree South Pole Telescope survey. Using APEX/LABOCA and Herschel, we have determined their IR SEDs. ALMA Cycle 0 molecular line spectroscopy and imaging have characterised this population, and found that they have a median redshift =3.5, while previous surveys found =2.5. While based on only 23 redshifts thus far, this difference is very significant, and can already distinguish between different flavours of galaxy formation models. We are continuing the redshift search of the lensed galaxies in ALMA Cycle 1, and of the lensing galaxies with X-shooter. Follow-up observations of our sample include [CII] lines with APEX and Herschel, and low-J CO lines with ATCA. This combination is providing a first statistically significant sample of the physical conditions in the ISM at redshifts up to 5.7.

10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — HCl fundamental band discovered in the ISM
Miwa Goto (LMU)

Abstract

I will talk about an uncompleted work of HCl absorption lines
found at 3.5 um in the line of sight to a young high mass star
CRL 2136. The layout of the talk is as follows:

1) HCl nu1=1-0 found
    + started in wrong way

2) Why are they so many?
    + chloride chemistry

3) What is CRL 2136?
    + must be in a disk/shell

4) Riddle of Tex
    + radiation pumping?
    + 'universal' rotational diagram?
    + cautionary note

01/07/13 (Monday)
12:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Talk — Telescope Mirrors from Arizona
Jim Burge (University of Arizona)

Abstract

Professor Jim Burge will discuss the challenges of making large telescope mirrors, and will present interesting solutions that have been implemented in Arizona. These include the production of large, lightweight glass mirror blanks, polishing technologies, and a variety of methods for measuring the surfaces. All are welcome at this talk.

Techniques developed at the University of Arizona for unique optics are now being applied in a production environment at Arizona Optical Systems, a private company that has grown out of the University research.  He will also discuss some of the benefits and challenges of moving from a research environment to one that emphasises production.

June 2013

27/06/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Self-Regulated Star Formation: From the Solar Neighborhood to High-Redshift Disks
Eve Ostriker (Princeton)
Download video |

Abstract

In disk galaxies ranging from our own Milky Way to high-redshift
systems, star formation takes place in very cold, dense cores, but
draws on a much larger reservoir of neutral atomic and molecular gas.
Recent surveys have spatially resolved both nearby galaxies and
high-redshift disks to establish increasingly precise empirical
correlations among gas, old stars, and the star formation rate (SFR).
Traditional single power law Kennicutt-Schmidt relations have been
refined to reveal three star-forming regimes for disks that extend
over more than six orders of magnitude in SFR.  In all regimes, gas
depletion timescales far exceed both global and local dynamical times.
To understand these empirical relations, it is necessary to consider
the physical state of the ISM, which is strongly coupled to recent
star formation through the feedback from massive stars -- including
copious UV radiation and powerful supernova blasts.  This energetic
feedback can lead to a state of self-regulated star formation.  Using
multiphase numerical simulations, we show that following the driving
and dissipation of turbulence in the warm/cold ISM, and resolving
scales down to pc in normal disks and 0.1 pc in starbursts, is
necessary to follow the detailed processes controlling SFRs.  The
equilibrium state can, however, also be captured with simple models in
which pressure powered by feedback balances gravitational confinement
of the warm/cold gas. Both numerical simulations and equilibrium
models are in remarkably good agreement with observations, and
demonstrate the importance of accurately modeling feedback in order to
understand galactic SFRs.

Video

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14:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Talk — Mirror image of ESO: looking at the Earth from space
Pedro Duque (ESA)

Abstract

As an ESA astronaut, Dr Duque took part in two space missions, first as Mission Specialist on the Space Shuttle Discovery, STS-95 mission, in 1998, and later in 2003, when he went on a 10-day mission to the International Space Station. Dr Duque is also an entrepreneur and has experience in the aerospace industry. During a special leave from ESA, between 2006 and 2011, he led an Earth observation project named Deimos Imaging S.L. (DMI), as Managing Director and then as Executive President. DMI is a fully private company that operates Earth Observation systems for commercial purposes. During this time, the company successfully launched its own satellite, named Deimos-1.

26/06/13 (Wednesday)
16:00, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — IceCube's hunt for extraterrestrial neutrinos
Anne Schukraft (RWTH Aachen)
25/06/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Does Size Matter? The Intrinsic Sizes of Radio Sources and Unification by Orientation
Michael DiPompeo (University of Wyoming, Laramie, USA)

Abstract

Unification by orientation is a ubiquitous concept in the
study of different types of active galactic nuclei (AGN). In these
models, various types of AGN are in fact intrinsically the same but
appear as different classes due to different viewing angles relative to
the line of sight.

This picture has historically been used to unify radio galaxies and
radio-loud quasars. A simple prediction of this model is that the
projected size of radio structure in radio galaxies should appear larger
than that of radio-loud quasars, because radio galaxies are seen at a
larger inclination relative to the radio jet axis. This was in fact
observed two decades ago; however, newer and larger samples have
revisited this question and found conflicting results.

An assumption in this projected size test is that the intrinsic sizes of
radio galaxies and radio-loud quasars are the same. However, it is
unlikely that there is a single intrinsic size, but instead the sources
are drawn randomly from an underlying distribution. I will discuss
simulations that test whether contradictory results regarding the
projected sizes of these sources can be reconciled by random sampling of
several intrinsic size distributions.

24/06/13 (Monday)
00:00, Garching | ESO Garching

Abstract

This conference aims to bring together observers and theorists covering the three kinds of galaxy halos - stellar, gaseous and dark matter. A wide range of topics from halo masses, gaseous interactions, abundances of halos, stellar content, relationship to galaxy scaling relations, co-evolution with host galaxies and their use as clues to galaxy formation will be presented. Details can be found here and further information is available by email. The deadline for registration is 01 April 2013.

21/06/13 (Friday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Talk — Monsters in the Dark – A Beginner's Guide to Black Holes
Timothy Davis (ESO Garching)

Abstract

Black holes are some of the most enigmatic objects in the universe. They push our understanding of the concepts of time, distance and mass to breaking point. From the monsters lurking at the heart of every large galaxy, which can be millions of times more massive than the sun, to smaller examples that form from the crushed remains of dying stars, astronomers have worked for the last half a century to learn a little about these exotic objects.

Join me in a doomed journey into the heart of a black hole, as I give a beginner's guide to these strange objects, explaining what we know about how they form, grow and dissipate, and how ESO's facilities can be used to learn more about these fascinating beasts.

12:30, D29 | ESO Garching
Lunch Talk
Talk — Finding and Forming Star Clusters in Andromeda
Anil Seth (University of Utah)

Abstract

The Panchromatic Hubble Andromeda Treasury (PHAT) survey is obtaining six filter Hubble Space Telescope imaging of ~1/3rd of the Andromeda galaxy disk. The survey is nearly complete and promises to reveal the most extensive star cluster system known in any galaxy. I will discuss the "Andromeda Project", our crowd sourcing project to identify star clusters in the PHAT data. We are using these clusters to study the formation of stars, including the stellar and cluster initial mass functions, and the efficiency of star cluster formation.

20/06/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Water in space: from interstellar clouds to planet-forming disks
Ewine van Dishoeck (Leiden Observatory)
Download video |

Abstract

Water is a key molecule in the physics and chemistry of regions in which new stars and planets are born. In the 'Water in Star-forming Regions with Herschel' (WISH) Key Program, we have obtained a comprehensive set of gaseous water data toward a large sample of well-characterized protostars, covering a wide range of masses and luminosities -from the lowest to the highest mass protostars-, as well as evolutionary stages -from the earliest stages represented by pre-stellar cores to the late stages represented by the pre-main sequence stars surrounded only by disks. The data probe dynamical processes associated with forming stars and planets (outflow, infall, expansion), test basic gas-phase and gas-grain chemical processes, and reveal the chemical evolution of water into planet-forming disks and icy solar system objects such as comets. Recent Atacama Large Millimeter/submillimeter Array (ALMA) images of transitional disks revealing sites where planetesimal formation is currently taking place will be presented as well.

Video

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12:30, D29 | ESO Garching
Lunch Talk
Talk — The Good and Stable Life of Galaxy Structure and Evolution
Gerhardt Meurer (ICRAR / U. West Australia)

Abstract

Our universe has passed the peak of star formation activity. Galaxies are accelerating away from each other, and their evolution is becoming more dominated by secular proceses. Indeed, observations show that galaxy disks have reached an equilibrium stability throughout their optically bright portions and beyond. I will show that the assumption of a uniform stability provides a good model for the structure of present day disk galaxies. It allows us to resolve some long known puzzles and provides a bridge between star formation, the gas and dark matter within galaxies. I will describe our current work on the constant stability disk models and prospects for understanding the main-sequence of star forming galaxies and their evolution.

19/06/13 (Wednesday)
16:00, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Strangeness physics in the nuclear enviroment
Oton Vazquez (TUM)
18/06/13 (Tuesday)
10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — An enhanced carbon chemistry in disks around very low-mass stars and brown dwarfs?
Ilaria Pascucci (Lunar and Planetary Laboratory, Univ. of Arizona)

Abstract

There is growing observational evidence that disk evolution is stellar-mass dependent. In this talk, I will show that these dependencies extend to the atomic and molecular content of disk atmospheres. I will summarize the main results from a unique dataset of high-resolution Spitzer/IRS spectra from 8 very low-mass star and brown dwarf disks. I will present the first detections of ionized neon, molecular hydrogen, carbon dioxide, and water in these disks and discuss implications for the heating and ionization of disk atmospheres. Finally, I will show that BD disks have on average higher C2H2/HCN and HCN/H2O line flux and column density ratios than TTauri disks. I will speculate on the implications of these trends for the O/C ratio in inner disks and the bulk composition of rocky planets.

13/06/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Booms, Burps & Bangs: The Dynamic Universe
Shri Kulkarni (Caltech)

Abstract

That occasionally new sources ("Stella Nova") would pop up in the heavens was noted more than a thousand years ago. The earnest study of cosmic explosions began in earnest less than a hundred years ago. Over time we have come to appreciate the central role of supernovae in synthesizing new elements (and making life as we know possible). The Palomar Transient Factory (PTF), an innovative 2-telescope system, was designed to explicitly to chart the transient sky with a particular focus on events which lie in the nova-supernova gap. PTF is now finding an extragalactic transient every 20 minutes and a Galactic (strong) variable every 10 minutes. The results so far: classification of 2000 supernovae, identification of an emerging class of ultra-luminous supernovae, the earliest discovery of a Ia supernovae, discovery luminous red novae, the most comprehensive UV spectroscopy of Ia supernovae, discovery low energy budget supernovae, clarification of sub-classes of core collapse and thermo-nuclear explosions, mapping of the systematics of core collapse supernovae, identification of a trove of eclipsing binaries and the curious AM CVns.

12/06/13 (Wednesday)
16:00, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Brane induced gravity: Addressing the cosmological constant problem in more than five dimensions
Florian Niedermann (LMU)
11/06/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Towards a more comprehensive understanding of exo-planetary worlds with direct imaging
Laurent Pueyo (STScI)

Abstract

Direct imaging mitigates selection effects inherent to the currently known exo-planetary population since it is sensitive to objects in an orbital space orthogonal to the one available with indirect methods. Upcoming campaigns will survey young and adolescent stars and probe for signatures of their formation history using instruments designed for high-contrast imaging. In the first part of this presentation I will discuss the wealth of information accessible using such surveys. I will describe current methods and ongoing projects aimed not only at identifying exo-planetary systems but also at estimating their bulk physical properties and atmospheric chemistry. I will in particular highlight our recents results, obtained using both the HST NICMOS Archive and the Project 1640 Integral Field Spectrograph installed at the Palomar Hale Telescope, that provide new insights regarding the true nature of a known exo-planetary system. Direct imaging is moreover envisioned as the preferred method to search for biomarkers in the atmosphere of earth-analogs, and answer one of humanity's most ancient questions "Are we alone?". This endeavor presents daunting technical challenges: such science requires to detect a planet whose signal is ten order of magnitude fainter than its host star. In the second part of this presentation I will review recent progress in high-contrast coronagraphic technologies spurred by this ambitious goal, with a particular emphasis on our work in high-precision modeling and experimental demonstration of phase induced amplitude modulation concepts. Technology demonstration efforts in this field have been focused on un-obscured off-axis apertures, because of the long standing belief that light diffracted by the secondary support structures and segment gaps would be a major hindrance to reaching the desired contrast. This places considerable constraints on future observatory architectures. I will present a solution to this problem and show that, using concepts and technologies already developed for monolithic un-obscured telescopes, high-contrast can in principle be achieved with any aperture geometry, even in the presence of a central obscuration and segment gaps.

06/06/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Epic Astrobiology
Caleb Scharf (Columbia University, New York)
Download video |

Abstract

The study of life, its origins, forms, and possible presence beyond the Earth is experiencing a renaissance. Much of this is driven by discoveries here, on Mars and in our solar system, and especially in the abundant and diverse population of planets around other stars. I will review some of the more interesting pieces of science, and discuss the theoretical and observational challenges that are particular for astronomy, as well as ways in which we're making progress and what we can expect from this odyssey in the near future.

Video

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05/06/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Higgs Physics at Linear Colliders - Exploring Electroweak Symmetry Breaking with the Next Large Collider at the Energy Frontier
Frank Simon (MPP)
04/06/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — The Hawk-I UDS and Goods Survey (HUGS): Early results
Adriano Fontana (INAF, Astronomical Observatory of Rome)

Abstract

The Hawk-I UDS and Goods Survey (HUGS) is the result of an a ESO Large Program that has just been completed.
It exploits the unique capabilities of Hawk-I to collect the deepest Near-Infrared images ever obtained over an area of about 1/10 os square degree, i.e. large enough to be representative of the high redshift Universe.
The survey is focused on two extragalactic fields (UDS and GOODS-S) where deep multiwavelength data are also available, especially those coming from the HST Treasure Program CANDELS. Combined with UltraVISTA, this survey will constitute an invaluable, probably definitive, legacy from ESO instrumentation ahead of the advent of E-ELT and JWST.
I will present the final data set and show early science results, showing that the HUGS data are be decisive to i) locate and measure the Balmer break at high redshift, in order to properly measure masses, ages and dust content at z > 4; ii) assemble the first complete sample of galaxies at z > 4, without the limitations of UV-selected samples, and iii) decisively secure redshift estimates for the most elusive objects at z > 4, like quiescent or evolved Lyman-Break Galaxies.

10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — Combined effects of HII regions and stellar winds on molecular clouds
James Dale (Excellence Cluster 'Universe')

Abstract

A wealth of observations from Spitzer, WISE and Herschel show that the structure and appearance of many star-forming regions is dominated by feedback. However, it is less clear from these data what are the effects of feedback on the dynamical states of the clouds and their embedded clusters, or on the ongoing star formation process. For the first few Myr after the birth of the first O-stars, the two most important feedback processes are photoionization and stellar winds. While there are numerous simulations of the effects of HII regions on turbulent clouds, there are few in which winds are studied, and none at all in which both types of feedback are allowed to act. I will present numerical simulations of the influence of both photoionization and stellar winds on molecular clouds with a range of masses. I will discuss how the two processes interact with each other and the implications for cloud/cluster disruption, triggered star formation, and the eventual explosion of the first supernovae.

09:30, IPP-L130 (IPP, Garching) | ESO Garching
Talk — Mini-workshop on Correction of Telluric Lines

Abstract

As part of  the Austrian In-Kind contribution, a  tool to correct for
telluric absorption and emission lines  has been developed, based
partly on an IDL prototype provided by one of us.

 The tool  is about  to be  released to ESO  with the  aim to  make it
publicly available in the  near future. Although a significant testing
phase has already taken place, we would like to better determine
- its accuracy,
- possible impacts on observational strategies.

 Therefore, we are  organizing a workshop where these  points could be
assessed, based  on diverse sets of  data. It will take  place in both
Garching  and  Vitacura  on  June  4th  and  only  for  the  following
instruments: CRIRES, XSHOOTER and VISIR.

 Based  on the  results we obtain during this meeting,  we will  probably organize
another workshop for other spectrographs.

 Hence,  we are  calling on  your  participation if  you have  reduced
spectroscopic data obtained with any  of the above instruments. We aim
at as diverse science cases as possible.

 Here is the schedule:

 

Tuesday May 2nd:
Deadline for  submission of emails with intent  to participate. Please
send  the following information  to Jakob  Vinther ,
with cc to Alain Smette , and Pascal Ballester
:

1. which instrument was used?
2. what is the science case (what were the data obtained for)? (one
   line maximum)
3. do you need to  correct for telluric emission or  absorption lines?
   or both?
4. have  you already used another technique/method  for correcting the
   telluric lines? if yes, which one? (absorption line: telluric star,
   emission   lines:  nodding,   Rick  Davies'   OH   algorithm,  ...)
5. agreement that  a  figure based  on  your data  together with  the
   telluric corrected spectrum could be  used in the tool user manual;
   indicate restriction if necessary.

Tuesday May 15th:
Deadline for  submission of test data: 
this is required in order to assess that the data are in proper format
and that we  have time to go back  to you in case of  problems on this
respect. Information on how to  submit the test data will be provided
to registered participants.

 

In  addition, it  is  also wise  to provide  at  this time  a list  of
spectral  regions which  are  affected by  intrinsic  features of  the
science target and should not be used by the fitting algorithm used by
the tool  and another  one with  the bad pixels.   These lists  can be
modified in real time during the workshop itself.

We  will   then  contact  each  participant   regarding  the  software
installation.

Tuesday June 4th, local time for both Garching and Vitacura
(the workshop takes place on the same day, but not simultaneously...)
09:30 - 10:00 introduction, presentation & demonstation of the tool
              by a member of the Austrian In-kind team;
10:00 - 12:30 utilization of the tool by participants;
12:30 - 13:00 collection of feedback and summary.


May 2013

29/05/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Direct Dark Matter Search with the CRESST Experiment - Status and Future
Raimund Strauss (TUM)
28/05/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — The detailed view of the interplay of gas and stars in starburst galaxies: NGC 5253 as a case sample
Ana Monreal Ibero (IAA - CSIC, Granada)

Abstract

Nearby blue compact galaxies are a subgroup of starbursts that constitute ideal laboratories to test in detail the interplay between massive star formation and the surrounding gas, under similar conditions to those occurring when galaxies were forming. Given its proximity and the wealth of ancillary information available in all spectral ranges, a particularly well-suited example for the study of this interaction is NGC 5253.

We are carrying out a detailed analysis of the central region of NGC 5253 using optical integral field spectroscopy. The outcome of this work has been published in Monreal-Ibero et al. 2010, 2012, 2013 and Westmoquette et al. 2013. In this talk I will review the results presented so far. Among other topics, I will address the 3D structure of the physical properties (electron density, temperature and excitation) of the ionized gas. Also, I will present mapping of its chemical content and the relation with the Wolf-Rayet star population of this galaxy. Two elements, deserving a detailed discussion, will be highlighted: nitrogen and helium.

24/05/13 (Friday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Talk — Sailors, 
astronomers and the discovery of the southern sky
Frank Verbunt (Radboud Universiteit 
Nijmegen)

Abstract

The area around the southern celestial pole is invisible from Europe, and was therefore unknown to European astronomers until seafarers started traveling the southern seas after1500. The first detailed maps of the previously invisible area was made on the basis of measurements made by Dirck Keyser and Frederick de Houtman, during and after the first merchant voyage of Dutchmen to the Far East.

The talk describes the adventures accompanying the measurements, the controversy concerning priority, the grouping of the newly found stars in twelve constellations, and the spread of this knowledge across Europe in the form of globes, maps and catalogues. The talk ends discussing Halley’s accurate measurements on the island of St.Helena.

23/05/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Neutron stars in globular clusters: catch and lose
Frank Verbunt (Radboud Universiteit 
Nijmegen)

Abstract

Millisecond radio pulsars are abundant in globular clusters, as are their progenitors, the X-ray binaries. They are formed in close encounters between neutron stars and other stars and binaries, as realized soon after their discovery. A binary with a neutron star formed by a close encounter is in turn subject to further, secondary encounters. I describe my research with Paulo Freire (MPI f. Radioastronomie, Bonn) on possible relations between such secondary encounters and the observed properties of radio pulsars in globular clusters, and on a possible explanation for apparently young pulsars among them.

21/05/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Star Formation Rates and Scaling Relations in Molecular Clouds
Marco Lombardi (University of Milan)

Abstract

It has long been recognized that star formation occurs in dark molecular clouds, but the physical properties of these objects and the star formation process is still largely debated.  In this talk I will present recent investigations on the structure of molecular clouds and on scaling relations between star formation rates and molecular gas masses.  To obtain these results I correlate near-infrared extinction maps of a set of nearby molecular clouds with catalogues of protostars observed in the clouds.  With these data in hand I will show that there is a local equivalent of the Kennicutt-Schmidt law for star formation.

10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — The different paths of disk dispersal: a Herschel view on young and evolved clusters
Aurora Sicilia-Aguilar (Universidad Autonoma de Madrid)

Abstract

The short lifetime of protoplanetary disks poses strong constraints to
the formation of planetary systems - but fully dispersing a massive disk
in a short time can also be a problem. Multiwavelength observations
reveal a large variety of disks in clusters of any age, ranging from
diskless stars in young regions, to rare disks with strong accretion and
little evidence of evolution at 10 Myr. Objects found to be in an
intermediate state between disked and diskless systems (transition
disks) show also differences in disk structure and accretion properties.
In this context, Herschel/PACS observations offer important information
on the disk global properties and also on the structure of the
star-forming cloud. Exploring with PACS different types of
disks in very different clusters (the young Coronet cluster, the
intermediate-aged Tr37, and the old NGC7160 cluster), we find a large
variety of dispersing disks. Some systems appear to have inner holes and
large disk masses, while others have very reduced dust masses and no
holes, defining several distinct evolutionary paths. Why some disks
disperse at an early age while others continue to accrete for a long
time until they evolve in different ways seems to be an interplay of
various physical processes where the system's initial conditions and
environment probably play an important role.

16/05/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Cosmic Rays at the Highest Energies
Karl-Heinz Kampert (Bergische Universität Wuppertal)

Abstract

Recent data of giant air shower observatories, most importantly of the 3000 km^2 large Pierre Auger Observatory operated in Argentina, have led to a number of major breakthroughs in the field of ultra-high energy cosmic rays. Most importantly, a distinct flux suppression above 5∙10^19 eV has been has been established unambiguously. This, together with upper limits on photon and neutrino fluxes at ultra-high energy have ruled out particle physics motivated "top-down" source processes, such as the decay of super-heavy particles, to account for a significant part to the observed particle flux at the highest energies. Moreover, there are indications for an anisotropic distribution of the arrival directions of particles with energies greater than 5∙10^19 eV. These results are typically considered as strong support of source scenarios in which particle acceleration takes place at sites distributed similarly to the matter distribution in the universe, with energy loss processes in the CMB leading to the observed flux suppression (GZK-effect). However, the cosmic ray mass composition and the small level of anisotropies in arrival directions suggest that the end of the cosmic ray spectrum is not dominated by the GZK-effect but by an extragalactic source (or source population), possibly within the GZK-horizon, running at its maximum electromagnetic rigidity R=p/Z. In this talk, we shall review cosmic ray data at the highest energies, discuss their implications to understanding their origin, and we shall address some synergies to particle physics currently performed at the LHC.

15/05/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — The GERDA experiment for the search of neutrinoless double beta decay: status and perspectives
Matteo Agostini (TUM)
14/05/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Complex molecules in Orion
Tzu-Cheng Peng (ESO)

Abstract

The Orion molecular cloud 1 (OMC-1) is a unique environment for the study of interstellar chemistry, especially in the surroundings of the Orion BN/KL region. As one of the closest star-forming regions, many complex molecules have been detected toward Orion BN/KL, including a few deuterated molecules. In this talk, I will present the recent results from our IRAM PdBI observations and focus on two molecules, deuterated methanol CH2DOH and acetone (CH3)2CO. I will also discuss the deuterium chemistry and nitrogen/oxygen-differentiation in Orion BN/KL and their future prospects in the ALMA era.

08/05/13 (Wednesday)
16:30, Cluster Building, Boltzmannstr. 2, Garching | ESO Garching
Cluster Universe Colloquium
Talk — Merging neutron stars as sources for gold and gravitational waves
Andreas Bauswein (MPA)
07/05/13 (Tuesday)
12:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy for Non-Astronomers
Talk — Are we alone in the Universe?
Jorge Melnick (ESO Santiago)

Abstract

In 1960 the radio astronomer Frank Drake started a search of radio signals from extraterrestrial technologically advanced civilizations using the Green Bank radio telescope. In order to quantitatively discuss the possibility of finding other civilizations in our Galaxy, Drake wrote down the main factors that he thought would need to be addressed to understand the odds of finding radio signals from extraterrestrial intelligent beings. The product of these factors became known as the Drake Equation.

Advances in many fields of science since 1960 enable us today to use Drake's equation to make scientifically sound estimates of the number of intelligent civilizations expected to exist in our Galaxy. In this presentation I will show that using the best available data, the probability of finding intelligent life on other planets depends critically on Drake's longevity parameter: how long does a technological civilization manage to survive natural and self-induced threats?

12:30, D29 | ESO Garching
Lunch Talk
Talk — Lessons learned from detections of CO in two atypical comets
Lucas Paganini (NASA Goddard Space Flight Center)

Abstract

Recent results by the space-based NASA's DIXI and Japanese Akari missions demonstrated that the carbon chemistry in comets remains incompletely understood. DIXI found that the outgassing in comet 103P/Hartley 2 was driven primarily by carbon dioxide. The Akari survey of 18 comets revealed a significant abundance of CO2, but surprisingly it detected only upper limits for carbon monoxide in most comets comprising their sample. Our recent ground-based VLT/CRIRES observations showed a relative large amount of CO in Oort cloud comet C/2009 P1 (Garradd) at 2 AU, and also in the border-line Jupiter Family/Centaur comet 29P/Schwassmann Wachmann 1 at 6.3 AU. In this presentation, I will report these detections, compare them to existing studies, and explore possible links between chemical composition and cometary origins.

10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — Characterizing the Early Stages of Massive Star Formation: From Infrared-Dark Clouds to Hot Molecular Cores
Izaskun Jimenez-Serra (ESO)

Abstract

Observations at mid-IR and far-IR wavelengths carried out with the Spitzer and Herschel satellites have revealed that the ISM in our Galaxy is highly organized in cold and dense filamentary structures. The most massive ones are called Infrared-Dark Clouds (or IRDCs) and present typical masses that range from 1000 Mo to 10000 Mo. IRDCs are believed to be the initial conditions of massive star and star cluster formation, which is known to end in chemically rich, hot molecular cores (Hot Cores). Although a large effort has been done in the past to determine the global physical properties of these clouds and of their dense (and cold) clumps/cores, it still remains unclear what mechanisms are responsible for the formation of IRDCs, and how they fragment forming cold IRDC cores. In addition, the evolutionary sequence by which cold IRDC cores evolve into Hot Cores is poorly known, and information about the internal physical structure of these cores is still lacking. In this talk, I will present our recent results on several comprehensive studies of the kinematics and chemistry of the molecular gas i) toward a filamentary IRDC, G035.39-00.33; ii) toward a sample of cold IRDC clumps recently detected with Herschel; and iii) toward a massive Hot Core, AFGL2591 VLA 3. From these results, we find that the combination of complete molecular line datasets with modeling of the chemistry in star forming regions, is key not only to obtain information about the large-scale processes involved in the formation of IRDCs, but also to fully characterize the evolutionary sequence from cold IRDC cores to massive Hot Cores, with their internal physical structure.

02/05/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Direct imaging of exoplanets
Anne-Marie Lagrange (IPAG, Grenoble)
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Abstract

Most of the exoplanets known today have been discovered by indirect
techniques, based on the study of the host star radial velocity or
photometric temporal variations. The planet populations explored are
in the first 5-8 AU from the central stars, and have provided precious
information on the way planet form and evolve at such separations.
Direct imaging on 8-10 meter-class telescopes allows detection of
giant planets at larger separations (currently typically > 5-10 AU),
complementing thus indirect techniques.  So far, each of the -yet very
few- giant planets imaged provides an opportunity of unique dedicated
studies of their orbital, physical and atmospheric properties and
sometimes also on their interaction with "second generation", debris
disks. Actually, these few detections already challenge formation
theories.

I will present the results of direct imaging surveys obtained so far,
what they already tell us about giant planet formation and
evolution. Individual and emblematic cases will be detailed; they
illustrate what future instruments will routinely deliver for a much
larger number of stars. I will also point out the limitations of
direct imaging as well as the needs for further work in terms of
planet formation modelling.  I will finally present the tremendous
progress expected in this field thanks to forthcoming planet imagers
on 8-10 meter class telescopes, and on Extremely Large optical
Telescopes.

Video

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April 2013

30/04/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Holographic imaging of dense fields: an efficient "poor man's MCAO"
Rainer Schödel (IAA - CSIC, Granada)

Abstract

I present an algorithm for speckle holography that has been optimised for crowded fields. The algorithm was tested on a range of different instruments and targets and from the N- to the I-band. In terms of PSF cosmetics and stability as well as Strehl ratio, holographic imaging is equal to, if not superior, to the capabilities of most, currently available AO systems. It outperforms classical lucky imaging. Holography can relatively easily deal with anisoplanatic effects in dense fields. I will present the exciting results of our tests and will discuss the virtues and vices of the technique. In particular I will address the question in which situations holography can provide unique advantages, or present an alternative or complementary method to the more established techniques such as standard AO imaging or sparse aperture masking.

10:00, D29 | ESO Garching
Star and Planet Formation Seminar
Talk — An Orion protostar as seen with Herschel: OMC-2 FIR 4
Mihkel Kama (Leiden Observatory)

Abstract

The CHESS key programme has obtained Herschel/HIFI high-resolution sub-millimetre spectra of a number of protostars, including OMC-2 FIR 4 in Orion. In this talk, I will introduce the first findings of the OMC-2 subteam and discuss some aspects of broadband spectral surveys. I will particularly focus on the chemical inventory of the source and on the diversity of the line profiles, as well as discussing substructure, a new foreground photon-dominated region and evidence for an outflow. As an example of things to come, I will show results from a comparison with the Orion KL survey of Comito et al. (2005).

29/04/13 (Monday)
14:00, Fornax (ESO HQ, Garching) | ESO Garching
Workshop — AGN 101 for non-experts - everything you always wanted to know about accreting super-massive black holes, but were afraid to ask

Abstract

The idea is that we give people that are NOT working in AGN research  a very introductory overview about this exciting research topic. There  will be four 20 min review talks covering:

1) An overview of AGN - Paolo Padovani
2) Optical and Infra-red observation of AGNs: Why and what can we learn? - Vincenzo Mainieri
3) X-ray observations of AGNs: why and what can we learn? - Mirko Krumpe
4) The physical connection between AGN and their host galaxies - Grant Tremblay

There will be a 10 min question session after EACH talk. Our goal is that people from other research areas are introduced to the most important questions and results of current AGN research. The workshop will also be live-streamed to ESO Vitacura.

This workshop will be an experiment! Depending on the feedback and success we hope, that other research areas also organize introduction workshops in the future and teach us about their exciting science.

25/04/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Molecular gas and star formation in early-type galaxies
Martin Bureau (University of Oxford, UK)
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Abstract

Despite pervasive residual star formation, early-type galaxies are generally considered "red and dead", composed exclusively of old stars with little gas and no star formation. Here, the molecular gas content of early-type galaxies is constrained and discussed in relation to their evolution, providing a much greater understanding of the gas cycle in these objects and arguing for the continuing importance of (minor) mergers and cold gas accretion. Early-types also provide a new laboratory to study star formation, revealing unusual star-formation scaling relations.

First, nearly a quarter of local early-types are shown to possess a substantial amount of molecular gas, the necessary ingredient for star formation, independent of mass and environment. Second, a variety of molecular gas morphologies is revealed. The kinematics of the molecular gas and stars are often misaligned, implying an external gas origin in at least half of the systems in the field, while external gas accretion is shut down in clusters. Despite this, the kinematics of the molecular is often regular, allowing kinematic work ranging from Tully-Fisher studies to black hole mass measurements. Third, many objects appear to be in the process of forming regular kpc-size decoupled disks, and a star formation sequence can be sketched by piecing together multi-wavelength information. Early-type galaxies do not seem to systematically obey all our usual prejudices regarding star formation (e.g. Kennicutt-Schmidt law and far infrared-radio continuum correlation), suggesting a greater diversity of star formation processes than observed in disk galaxies. Last, a first step toward constraining the physical properties of the molecular gas in early-type galaxies is taken, by modeling the line ratios of temperature-, density- and opacity-sensitive molecules in a few objects.

Video

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23/04/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — A VLT-SUBARU synergy to establish the mass-metallicity relation of main sequence galaxies at z<2.5
Christian Maier (University of Vienna)

Abstract

The widely used reference mass-metallicity relation (MZR) at z>2 from the Erb et al. (2006) study has been affected by the sample selection and unknown AGN contribution, and was based on limited spectroscopic information (1-2 emission lines), yielding large uncertainties in metallicities.To better constrain the MZR of galaxies at z>2, we used VLT and SUBARU near-infrared spectroscopy to measure, for 22 MS galaxies compared to the Erb et al. study, and also an evolution of the fundamental metallicity relation (FMR) compared to the local relation.

19/04/13 (Friday)
12:30, D29 | ESO Garching
Instrument Lunch Talk
Talk — AMBER
Markus Wittkowski and Markus Schöller (ESO)
18/04/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Terzan 5: the remnant of a pristine fragment of the Galactic Bulge?
Francesco Ferraro (University of Bologna)
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Abstract

Terzan 5 is a stellar system commonly catalogued as a Globular Cluster
(GC), located in the inner Bulge of our Galaxy. Two distinct
sub-populations have been recently discovered in this system (Ferraro
et al. 2009, Nature, 462, 483). They define two well separated red
clumps in the (K, J-K) color-magnitude diagram (CMD) and show very
different iron content: ΔFe ~0.5 (such a large difference in iron
abundance has been found only in another GC-like stellar system, omega
Centauri, in the Halo of the Galaxy). Moreover, the abundance of light
elements measured in both sub-populations has been found not to follow
the typical anti-correlations observed in genuine GCs and the overall
chemical patterns of the two populations appear strikingly similar to
those of the Bulge stars (Origlia et al. 2011). These observational
results demonstrate that Terzan 5 is not a genuine GC, but a stellar
system that experienced complex star formation and chemical enrichment
histories. The strong chemical link with the Bulge, together with the
location in the inner region of it, suggest that Terzan 5 (at odds
with omega Centauri) is not the nucleus of an accreted dwarf galaxy,
but possibly the relic of one of the pristine fragments that
contributed to form the Bulge itself.

Video

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16/04/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Studying climate change using earthshine observations
Enric Palle (IAC, Spain)

Abstract

A major component of the Earth's radiation budget is the albedo, the amount of sunlight that the Earth reflects back to space and which never enter its energy budget. Traditionally the Earth's reflectance has been assumed to be roughly constant, but large decadal variability, not reproduced by current climate models, have been reported lately from a variety of sources. The reported albedo variability is much larger than the solar irradiance variability from maximum to minimum of solar activity, and thus has a larger potential to change the Earth’s radiation budget. The Earthshine project is a dedicated project aiming to measure the earth's albedo using the sunlight reflected from the bright and dark side of the Moon using small telescopes. Here, I will discuss the history of the Earthshine project, and its contributions to climate and exoplanet sciences.

12/04/13 (Friday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Understanding the evolving galaxies in the Local Universe
Ivy Wong (CSIRO)

Abstract

The Local Universe provides an excellent high-resolution laboratory for studying the detailed processes of star formation and galaxy evolution. In this seminar, I will present some highlights from multiwavelength star formation studies of nearby HI-selected galaxies as well as our latest results on galaxies in transition. I will show that: (i) selecting galaxies via their HI content is a good way of selecting a large variety of star-forming galaxies regardless of size/stellar luminosity; (ii) the upper mass end of the stellar IMF may not be uniform; (iii) nearby post-starburst galaxies occupy the low-mass end of the green valley and represent a population of galaxies which are quickly going from the blue cloud to the red sequence; and (iv) unlike strong gravitational interactions, ram pressure does not strongly induce star formation. In addition, I will describe the current progress of the ASKAP project.

11/04/13 (Thursday)
16:30, IPP Lecture Hall D2 (IPP, Garching) | ESO Garching
Talk — A Planck Bonanza - Talk 2: Planck's view of the Universe in front of the cosmic microwave background
Jim Bartlett (APC, University of Paris 7 and JPL Pasadena)

Abstract

The Planck survey has unearthed a wealth of information on the state of the Universe since recombination (i.e., since z~1000). We learn about large-scale structure in both luminous and dark matter through a variety of techniques: reconstruction of the matter perturbations through gravitational lensing of CMB anisotropies, mapping the distribution of star-forming galaxies across time (cosmic infrared background, CIB) and observation of the ionized gas through the Sunyaev-Zeldovich (SZ) effect in galaxy clusters and as an unresolved, diffuse background. We will discuss these results, how they constrain the cosmological model and how they address the key outstanding question of the relation between luminous and dark matter. In particular, we find a strong correlation between the CIB and the lensing signal, telling us about the dark matter halos hosting star- forming galaxies. We also find surprising tension between the observed SZ signals and expectations based on the standard LCDM model favored by Planck's primary CMB analysis. This tension suggests either the need for an extension to the base LCDM model or that clusters are significantly more massive than previously thought.

15:30, IPP Lecture Hall D2 (IPP, Garching) | ESO Garching
Talk — A Planck Bonanza - Talk 1: Planck's view of the cosmic microwave background: cosmological parameters, fundamental physics and early universe cosmology
George Efstathiou (IoA and Kavli Inst. for Cosmology, Cambridge)
09/04/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Towards solving the angular momentum problem for solar-type stars formation: interferometric mapping of the youngest protostars
Anaelle Maury (CfA Harvard)

Abstract

Low-mass stars form from the gravitational collapse of dense molecular cloud cores. The so-called Class 0 Young Stellar Objects (YSOs), mostly observed from cm to mid-infrared wavelengths, are believed to be the youngest accreting protostars: they are composed of the first embryo of star deeply embedded within an infalling envelope of cold gas and dust. The Class 0 phase is also the main accretion phase, and while accretion onto the central star continues in the Class I and Class II phases, it is by the end of the Class 0 phase that the disk and multiple systems are expected to be formed around the central young star. The initial conditions for the formation and subsequent evolution of both the young star(s) and circumstellar disk(s) are determined during this embedded stage, therefore studying the youngest YSOs during their embedded phase is crucial to establish a comprehensive scenario for the formation of solar-type stars.

I will present our current understanding of the earliest phases of star formation, with an emphasis on theoretical and observational scenarios developed in the past decade to describe the formation of multiple systems and protostellar disks.

I will then show the first results of an observational effort dedicated to solve the angular momentum in low-mass star formation:

the CALYPSO survey, conducted with the IRAM Plateau de Bure interferometer between 2010 and 2013.

I will show how these unprecedented observations allow us to propose a very dynamical scenario for the formation of both circumstellar disks and multiple systems, but also to make progress on our understanding of chemistry processes and jet launching mechanisms during the Class 0 phase.

04/04/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Cosmic Flows Project, Voyage to the Great Attractor
Helene Courtois (University of Lyon)
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Abstract

"Cosmic Flows" project is focused on producing observed galaxy distances for 30,000 galaxies with systematic errors below 2%, almost ten times the number currently known and a five-fold improvement in systematics. The resultant velocity field is providing initial conditions for constrained numerical cosmological simulations "CLUES". The observed and the simulated universe are then comparatively studied. This synergy of observations and theory distinguishes this program, and should lead to fundamental discoveries. Specifically, the program should give a definitive answer to an outstanding problem in cosmology since 1996 : the cause of the motion of 630 km/s of the CMB. On the path to this goal we are learning new informations on the dynamics of Large Scale Structures: the large coherent flows of galaxies away from voids and towards the Great Attractor region. We derive a most recent value for the Hubble constant at Ho=75 km/Mpc/s using SNIa. "Cosmic Flows" is bringing together unique expertise in radioastronomy, optical and space near-infrared surface photometry, theoretical astrophysics and numerical simulations. We tackle a frontier question: by learning our "cosmography", we look for where exactly are the Dark Energy and Dark Matter that dominate the cosmology?

Video

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02/04/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Luminous OB Cluster Formation in Molecular Hub-Filament Systems
Hauyu Baobab Liu (ASIAA, Taiwan)

March 2013

27/03/13 (Wednesday)
09:00, Fornax (ESO HQ, Garching) | ESO Garching
Workshop — The IAU, ESO, UNAWE, ESA Workshop on Public Outreach Information Management in Astronomy

Abstract

A Workshop on Djangoplicity (DP) in honour of Lars Holm Nielsen’s contribution to astronomy outreach information management.

26/03/13 (Tuesday)
15:30, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy Communication Seminar
Talk — The IAU and Astronomy for Development
J.C. Mauduit (IAU Office of Astronomy for Development)

Abstract

On 16 April 2011 the International Astronomical Union's (IAU) Office of Astronomy for Development (OAD) was launched jointly by the President of the IAU and the South African Minister of Science and Technology, at the South African Astronomical Observatory in Cape Town. The OAD was set up to realise the IAU's Strategic Plan, which aims to use astronomy as a tool for development. Prior to this, on 29th March 2011 a presentation was made to ESO staff regarding the implementation plans for the OAD, as part of ESO's Astronomy Communication Seminars. In this talk, JC Mauduit will present the latest developments at the OAD and the progress made towards its vision of "Astronomy for a Better World".

15:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Astronomy Communication Seminar
Talk — The IAU and Public Outreach
Sarah Reed (IAU Office for Astronomy Outreach)

Abstract

The International Year of Astronomy 2009 (IYA2009) demonstrated to the IAU the importance of appointing a global coordinator to promote and support astronomy outreach activities around the world. In September 2012, the IAU Office for Astronomy Outreach (OAO) was founded at the National Astronomical Observatory of Japan under the leadership of the IAU’s new International Outreach Coordinator, Sarah Reed. In this talk, Reed will briefly outline the goals of OAO and the synergy with the IAU Office of Astronomy for Development (OAD). She will also discuss the mutually supporting roles of IAU Commission 55, Communicating Astronomy with the Public, and the OAD’s Task Force 3, Astronomy for the Public, in promoting astronomy around the world.

12:30, D29 | ESO Garching
Lunch Talk
Talk — Bioastronomy with Planet Earth
Michael Sterzik (ESO)

Abstract

The quest for planets located in habitable zones, and, ultimately, life on extrasolar planets has already started. The origin of life in most extreme environments and the conditions for its evolution on Earth may be useful guides for our search of extraterrestrial Life. The emergence of photosynthesis early in Earths history marked the beginning of fundamental changes in climate and furnishes significant amounts of molecules far from chemical equilibrium into the atmosphere.

I will present linear polarisation spectra of Earthshine obtained with FORS2. The measurements demonstrate that polarimetric spectra of the Earth contain robust information on biosignatures. (Spectro)polarimetry may become key for the imminent search for life on exoplanets with the next generation of giant, ground-based, telescopes.

21/03/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The Galactic Bulge
Ken Freeman (Mount Stromlo Observatory)
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Abstract

The boxy Galactic Bulge is believed to have formed long ago through a bar-forming and bar-buckling instability of the Galactic disk. In order to study the chemical and dynamical properties of this bulge, we have acquired spectra of 28,000 red giant candidate stars towards the bulge, and I will describe the outcome of this large survey (the ARGOS survey). We are able to estimate the distances for all of these stars, and remove several thousand stars which lie in the foreground or background of the bulge. The chemical properties of the bulge stars show that the bulge-forming instability moved stars from the early thin and thick disk into the bulge. These stars are now locked into the bulge as chemically identifiable fossils of the early disks. We are not able to put useful limits on the presence of an additional classical (merger-related) bulge component in the inner Galaxy, but our kinematical data are fully consistent with the predictions of the instability formation scenario.

Video

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15/03/13 (Friday)
12:30, D29 | ESO Garching
Instrument Lunch Talk
Talk — APEX instrumentation
Carlos De Breuck (ESO)
14/03/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — How the Milky Way Built its Disk
Hans-Walter Rix (MPIA Heidelberg)
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Abstract

If we could map the global structure of the Milky Way's stellar disk, looking only at stars of a given age or abundance, it would be a direct route to delineating empirically how a typical large galaxy disk was built up. We have solved the problem of how to look at our own Galaxy this way, using large ground-based spectroscopic surveys. I will show how the overall radial and vertical structure of the Milky Way's disk changes as a function of stellar abundances, which may serve as proxies for stellar ages. Through comparison with disk formation simulations, I will also discuss what this may mean for the build-up of the Milky Way disk and its evolution. Slicing the Milky Way's disk into sets of such stellar mono-abundance populations is also proving a powerful way of constraining the Galactic potential.

Video

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12/03/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — The far-IR Luminosity Function in void-Lemaitre-Tolman-Bondi (LTB) models
Alvaro Iribarrem (ESO)

Abstract

The Luminosity Function (LF) is an important tool in studying the redshift evolution of galaxy populations. It is, however, dependent on the cosmological model assumed in its computation. Despite the current constraining power of the combined observational results from the Supernovae (SNe) Ia hubble diagram, the Cosmic Microwave Background (CMB) power spectrum, the Baryonic Accoustic Oscillation scale, and the various measurements of the Hubble constant, there is still debate on the cosmology, with some alternative models being able to fit many of these observations simultaneously. After a quick, conceptual introduction to the giant void class of Lemaitre-Tolman-Bondi (LTB) models, their main features and limitations, I will proceed to present the LF computed using data from the Herschel/PACS Evolutionary Probe (PEP) survey, assuming both the standard and two parameterizations of giant void models. I will show that the characteristic density and luminosity of the FIR selected sources is quite robust over a change in the cosmology, over the whole redshift interval, from z~0 to z~3, but also that, at low redshifts, there is a significant difference between the void models faint-end slopes and the one in the standard model.

10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — The interplay between X-ray photoevaporation and planet formation
Giovanni Rosotti (USM Munich)

Abstract

Planets form from gas and dust discs that orbit young stars. The evolution and final dispersal of protoplanetary discs holds therefore a particular importance, especially in terms of timescales. In particular, observations reveal that most (if not all) discs go through the "transitional disc" phase, which is currently interpreted as the last stage before the disc dispersal. Photoevaporation and planet formation have been studied as possible physical mechanisms responsible for the formation of these discs. While it is likely that more than one mechanism is at play, the interplay between them has until now not been studied in detail. I will show results from 2d simulations of protoplanetary discs undergoing X-ray photoevaporation with an embedded giant planet. By reducing the mass accretion flow onto the star, discs that form giant planets will be dispersed at earlier times than discs without planets by X-ray photoevaporation. This process, planet formation induced photoevaporation (PIPE), is able to produce transition disc that for a given mass accretion rate have larger holes when compared to standard X-ray photoevaporation. This constitutes a possible route for the formation of the observed class of accreting transition discs with large holes, which are otherwise difficult to explain by planet formation or photoevaporation alone. Moreover, assuming that a planet is able to filter dust completely, PIPE produces a transition disc with a large hole and may provide a mechanism to quickly shut down accretion. This process appears to be too slow however to explain the observed desert in the population of transition disc with large holes and low mass accretion rates.

07/03/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Using massive clusters to probe structure formation and the first galaxies in the Universe: the CLASH project
Piero Rosati (ESO)
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Abstract

Massive galaxy clusters represent important signposts in the history of structure formation and evolution, and are also natural gravitational telescopes which are able to bring lensed primordial galaxies from the earliest epochs into comfortable reach for detailed studies. The CLASH project (Cluster Lensing And Supernova survey with Hubble) combines an HST Treasury program to obtain panchromatic 16-filter (ACS+WFC3) imaging of 25 carefully selected massive clusters, with panoramic ground-based imaging, a large spectroscopic campaign with VLT/VIMOS and other multi-wavelength observations. This program was designed to provide landmark progress in the investigation of the mass distribution of galaxy clusters, at ~0.4, specifically the measurement of dark matter and total density profile shapes, over a wide radial range and over cosmic time, thus testing distinctive predictions of the LCDM cosmological model and structure formation scenario. The homogeneity and high quality of this combined data set allows us to probe matter density profiles with unprecedented accuracy over 3 decade in radius from a combination of independent probes (lensing, X-ray, and dynamics), with a significant mitigation of systematic effects.

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05/03/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Possible detection of a large population of white dwarfs in the direction of the Galactic bulge
Annalisa Calamida (STScI)

Abstract

We performed time-series observations of 12 ACS/WFC3 fields in the Sagittarius low-reddening window in the Galactic bulge, by sampling the region every two weeks for seven consecutive months. The aim of the project is to detect isolated black holes and neutron stars through astrometric microlensing.

I will present in this talk preliminary results based on the reduction of four ACS fields. The composite V,I-band photometric catalog includes about 1 milion stars down to V = 30 mag and a large population of candidate white dwarfs. Proper motions have been measured for the SWEEPS ACS field, a deep observation of which was taken in 2004. The time baseline of eight years allowed us to achieve a proper motion accuracy of better than 0.15 mas/yr at V = 26 mag in both coordinates. The analysis of the proper motions shows that most of the white dwarfs have higher velocities compared to the bulk of bulge stars.

01/03/13 (Friday)
09:00, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching

Abstract

The E-ELT project office is organising a four-day workshop to gather community input for the E-ELT instrumentation roadmap. The workshop will address the instruments to follow on from the two first-light instruments. Presentations are invited on new or updated E-ELT science cases, shaping the definition of the upcoming instrument suite and also on ideas for instrumentation and technologies matching the E-ELT instrumentation roadmap. In particular, the project aims at gathering input on the science case and requirements for a mid-infrared instrument, a multi-object spectrograph and a high spectral resolution spectrograph.

February 2013

28/02/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Extreme Astrophysics with Revolutionary Radio Telescopes
Rob Fender (University of Southampton)
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Abstract

Against the background of the (mostly) Unchanging Heavens, the universe is punctuated by dramatic explosions and accretion events in which extremes of density, pressure, temperature, magnetic field and space-time curvature are reached which will be forever unattainable in any Earth-bound laboratory. Studying these events allows us to probe both the underlying physics as well as the effect of these massive injections of energy on the surrounding interstellar and intergalactic media. Such events are ubiquitously associated with radio emission, resulting from the interaction of highly-accelerated electrons with magnetic fields. In this talk I will outline how and where in the universe we use radio emission to understand the budget of explosive feedback, and how a new generation of radio telescopes en route to the Square Kilometre Array have the potential to revolutionize our understanding of extreme astrophysics.

Video

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09:00, Ismaning Buergersaal | ESO Garching
Workshop — Shaping E-ELT Science and Instrumentation
27/02/13 (Wednesday)
09:00, Ismaning Buergersaal | ESO Garching
Workshop — Shaping E-ELT Science and Instrumentation
26/02/13 (Tuesday)
10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — The survival of molecules in cavities of transition disks
Simon Bruderer (MPE)

Abstract

Planet formation is closely related to the evolution of protoplanetary disks. Before protoplanetary disks disperse, they enter a transition phase where a gap in the dust surface density opens up. Different mechanism for the origin of this gap have been suggested, including the clearing up by a newly formed planet, grain growth or photoevaporation. The amount of gas inside the gap is still unclear, however key to distinguish between the different scenarios. Since proto-planetary bodies evolve significantly in the transition disk phase, knowledge of the disk dissipation process is crucial for the understanding of planetary system evolution. ALMA allows for the first time to spatially resolve the gas content of cavities. To analyse the new observations and study the physical/chemical composition of gas inside a gap, we have developed new radiative thermo-chemical models of the inner disk. The models are based on Bruderer et al. 2012 and solve for the chemical abundance self-consistently with the dust radiative transfer, thermal balance and molecular/atomic excitation. The models are used to constrain the conditions that allow molecules to survive in cavities. I will further present ALMA predictions from a grid of transition disk models.
09:00, Ismaning Buergersaal | ESO Garching
Workshop — Shaping E-ELT Science and Instrumentation
25/02/13 (Monday)
13:30, Ismaning Buergersaal | ESO Garching
Workshop — Shaping E-ELT Science and Instrumentation
22/02/13 (Friday)
12:30, D29 | ESO Garching
Instrument Lunch Talk
Talk — VST-OmegaCam
Dietrich Baade & Monika Gotzens (ESO)
21/02/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Recent insights into Planet Formation
Hilke Schlichting
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Abstract

I will discuss recent insights that we have gained into planet formation from our solar system. In the first half of my talk, I will focus on the Kuiper belt, located at the outskirts of our planetary system, which provides a snapshot of earlier stages of planet formation and is therefore an ideal laboratory for testing planet formation theories. I will show how we can use the Kuiper belt size distribution to gain new insights into runaway growth and initial planetesimal sizes during planet formation and show how studying small km-sized Kuiper belt objects enables us to put our Kuiper belt into context of debris disks around other stars. In the second half of my talk, I will review dynamical models and geochemical constraints from the Earth, Moon and Mars and discuss their implications for the last stage of terrestrial planet formation.

Video

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19/02/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — On the evolution of Omega HI over cosmological time scales
Tayyaba Zafar (Laboratoire d'Astrophysique de Marseille)

Abstract

Damped absorbers seen in the spectra of background quasars are a unique probe to select HI rich galaxies. These galaxies allow to estimate neutral gas mass over cosmological scales, which is a possible indicator of gas consumption as star formation proceeds. The damped Lya absorbers (DLAs) and sub-damped Lya absorbers (sub-DLAs) are believed to contain a large fraction of neutral gas mass in the Universe. A search for DLAs and sub-DLAs is made in the reduced archival Ultraviolet Visual Echelle Spectrograph (UVES) dataset of 250 quasars. Because of a chosen redshift window a statistical analysis on 195 quasars is performed. For better statistics, the dataset of archival UVES quasars is analyzed in conjunction with other DLA and sub-DLA samples from the literature. Using the sample, redshift evolution of the number density and the line density are derived for DLAs and sub-DLAs and compared with the Lyman limit systems (LLSs) from the literature. Furthermore, the column density distribution, down to the sub-DLA limit is determined. The redshift evolution of column density distribution is also determined, indicating presence of more sub-DLAs at high redshift as compared to low redshift. The column density distribution function is further used to determine the HI gas mass density, at 1.5 < z < 5.0. The complete sample shows that sub-DLAs contribute 10–20% to the total gas mass density. In agreement with previous studies, no evolution of gas mass density is seen from low redshift to high redshift, suggesting that star formation solely cannot explain this non-evolution and replenishment of gas, and/or recombination of ionized gas is needed.
15/02/13 (Friday)
12:30, D29 | ESO Garching
Instrument Lunch Talk
Talk — HARPS
Gaspare Lo Curto (ESO)
14/02/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The Solaris Project: A Timing Survey For Circumbinary Planets Around Eclipsing Binary Stars
Maciej Konacki (Torun, Poland)
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Abstract

The SOLARIS project aims to detect from the ground circumbinary planets with the timing of eclipses of eclipsing binary stars. A network of four robotic 0.5-m telescopes on three continents (Australia, Africa and South America) will be established to carry out high cadence, high precision photometry of a sample of eclipsing binary stars. Three of the telescopes are already installed and the fourth one will become operational in the second half of 2013. The project's web site is www.projectsolaris.eu/. This effort is accompanied by our radial velocity (RV) survey for circumbinary planets which employs our novel iodine cell based technique tailored to provide very high precision RVs of double-lined binaries. Altogether these two efforts, targeting about 300 eclipsing binary stars, constitute the biggest ground based survey for circumbinary planets. Moreover, we expect that both these efforts will have a significant impact on the observational stellar astronomy. In particular for at least half of our sample we expect to deliver masses of the stars with an accuracy 10-1000 times better than the current state of the art.

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12/02/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — HELGA: The Herschel Exploitation of the Local Galaxy Andromeda
Jacopo Fritz (University of Gent)

Abstract

I will present the results from a large-field infrared survey of our neighbour galaxy M31. We have obtained Herschel images of a ~5.5×2.5 degree area centred on Andromeda. Using 21-cm atomic hydrogen maps, we are able to disentangle genuine emission from M31 from that of the foreground Galactic cirrus, allowing to recognize dusty structures out to ~31 kpc from the centre. After performing an analysis of the broad characteristics of the infrared emission, we fully exploited Herschel resolution and performed a SED fitting analysis on a pixel-by-pixel basis which allowed us to map the properties of dust, such its temperature and emissivity, and study them as a function of the galactocentric distance. We have then used our data in combination with UV and 24 micron images, to study the characteristics of the star formation activity, through the well known Kennicutt-Schmidt law. Finally, by de-projecting Herschel images and running an ad-hoc source extraction algorithm, we reconstruct the intrinsic morphology, and the spatial distribution of the molecular complexes.
07/02/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Chemical and physical processes in the earliest phases of star formation
Paola Caselli (University of Leeds)
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Abstract

The initial conditions in the process of star and planet formation are to be found in pre-stellar cores, which are dense (n_H > 10^5 cm-3), cold (T < 10 K), centrally concentrated and gravitationally contracting regions embedded in molecular clouds. Knowledge of the physical structure and kinematics of pre-stellar cores is needed to put constraints on theories of star and planet formation. This requires a good understanding of the pre-stellar core chemical structure, as spectral line profiles of trace species provide the only diagnostics of the dynamics leading to star and planet formation. Because of their simple structure and quiescent nature, pre-stellar cores are also ideal laboratories in which to measure key astrophysical processes and parameters. I will review work on pre-stellar cores in low-mass star-forming regions, showing Herschel observations and how ALMA will unveil the still unexplored central few hundreds AU of pre-stellar cores, the future stellar system cradles. I'll then move to high-mass star-forming regions and show that our work on nearby pre-stellar cores has provided a way to unveil massive starless cores and test star formation theories. Cycle 0 ALMA and OT2 Herschel data will be presented.

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05/02/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Pushing the limits of Spitzer IRAC: from exoplanets to clusters of galaxies
Jessica Krick (IPAC, Caltech)

Abstract

The aim of this talk is to introduce you to work to push the limits of the Infrared Array Camera (IRAC) on Spitzer for the benefit of increased scientific performance. IRAC currently operates two InSb 256x256 arrays at 3.6 and 4.5 microns and has a 5arcminute FOV with 1.2 arcsecond pixels. Three new advances of the instrument will be presented along with the science they enable. 1) Recent developments in understanding and mapping the intrapixel gain variations enable detailed studies of extrasolar planet and brown dwarf atmospheres. IRAC is uniquely suited for exoplanet characterization due to the favorable planet to star ratio in the infrared and the photometric precision of the instrument. I will show an example of a Wasp 33 light curve where the increased precision allowed by gain mapping is accurately able to disentangle the periodic signals of this known delta Scuti pulsator from its hot Jupiter planet. 2) Moving further afield, I will also discuss instrumental limits to low surface brightness work with IRAC through a study of the ages and masses of intracluster light (ICL) plumes and the M87 halo in the Virgo cluster for the purpose of understanding galaxy cluster formation mechanisms. Combined with optical data, we find that large plumes can account for the total ICL content of the cluster implying that we do not need to invoke ICL formation mechanisms other than gravitational mechanisms leading to bright plumes. 3) Lastly, I will present the use of weekly calibration data taken over the 8.5 year lifetime of the mission for a novel, in situ, study of the zodiacal cloud. This is compared to both Cosmic Background Explorer Diffuse Infrared Background Experiment data and a zodiacal light model based thereon.
01/02/13 (Friday)
12:30, D29 | ESO Garching
Instrument Lunch Talk
Talk — HAWK-I
Elena Valenti, Ralf Siebenmorgen (ESO)

January 2013

31/01/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — New clues to the type-Ia supernova progenitor puzzle
Dan Maoz (Tel Aviv University)
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Abstract

Type-Ia supernovae (SNe Ia) are thermonuclear bombs in which about a solar mass of carbon and oxygen is burned into iron-peak elements. The "explosives" are apparently a white dwarf. SNe Ia are excellent cosmological distance indicators, and as such provided the first evidence that the cosmic expansion is accelerating. However, despite their confident use in cosmology, a major embarrassment remains: no one knows, based on direct evidence, what exactly is exploding. Two scenarios have been long considered for explaining how a white dwarf can ignite and explode as a SN Ia. In the "single-degenerate" picture, a white dwarf accretes matter from a companion "normal" star (i.e. a star with a classical equation of state), until approaching the Chandrasekhar limit and igniting. In the "double-degenerate" picture, a close white-dwarf binary loses energy and angular momentum to gravitational waves, until the two white dwarfs merge, thus starting the ignition and the thermonuclear runaway. However, both scenarios have theoretical and observational problems, and little or no direct evidence to support them. SN Ia rates, as a function of cosmic time and environment, can provide clues. I will show how many recent measurements are converging toward a single SN Ia "delay-time distribution" - the SN Ia rate, as a function of time, that would follow a hypothetical short burst of star formation. The emerging function is remarkably similar to what one expects from white dwarf mergers, based directly on the fundamentals of gravitational wave emission. A measurement of the Galactic binary white dwarf merger rate also suggests there may indeed be enough such mergers to serve as the SN Ia progenitors.

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30/01/13 (Wednesday)
12:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Lunch Talk
Talk — SALT: a segmented mirror telescope on the cheap
David Buckley (SALT Science Director)

Abstract

Construction of the Southern African Large Telescope was completed in 2005 at a the relatively modest cost of ~$20M. Following a rather protracted commissioning period, during which a number of problems were addressed, it entered full science operations in 2011. This talk will discuss the design and construction of SALT and its First Generation instruments and the operational model for the telescope. Some initial science results will be presented plus a summary of the new instrumentation which is currently under construction.
29/01/13 (Tuesday)
10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — Herschel observations of gas in protoplanetary disks
Davide Fedele (MPE)

Abstract

I will present recent far-infrared spectroscopic observations of protoplanetary disks taken with Herschel-PACS as part of the DIGIT key-project. The survey includes 20 Herbig AeBe stars and some T Tau stars. Multiple atomic fine structure and molecular lines are detected, including the major O- and C-containing species: [OI], [CII], CO, OH, H2O, CH+. The Herschel observations probe the existence of a warm molecular layer at intermediate distance from the star. We used a LTE slab model to derive the physical properties of the gas (column density, excitation temperature and emitting region). The comparison with near- and mid-infrared spectroscopic observations allows us to constraint the relative abundances of multiple species in different parts of the disk. I will also present Herschel/HIFI observations of CO J=16-15 and C+. The velocity resolved line profiles allow us to locate the warm gas directly.
24/01/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Reionisation via the Lyman-alpha line
Jamie Bolton (University of Nottingham)
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Abstract

The first luminous objects to form in the Universe produced ultra-violet photons which photo-ionised and heated the previously cold and neutral intergalactic medium (IGM). Observing the impact of the reionisation era on the IGM therefore provides us with an indirect probe of the formation and evolution of the first galaxies. Low frequency radio observations of the high redshift Universe will provide an exciting new window into this important epoch in the near future, but in the present the Lyman-alpha line (both in absorption and emission) can also inform us about the physical state of the high redshift IGM. In this talk I will briefly review existing observational constraints on the reionisation era, before going on to discuss new developments arising from observations of Lyman-alpha absorption around bright quasars at z=6-7 and the abundance of Lyman-alpha emitting galaxies approaching z=7. These measurements may be used to test existing theoretical models for reionisation, and can yield fresh insight into the timing of reionisation as well the nature of the first sources of light in the early Universe.

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22/01/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Commissioning ALMA: Experiences and achievements of two years in Chile
Tim van Kempen (Leiden Observatory)

Abstract

Within the ALMA project, I spent two years as a Commissioning Scientists with the CSV team led by Richard Hills. This talk will show how much has happened with ALMA over the two years. This will be done using the lifecycle of an antenna from being delivered to the OSF all the way to its delivery to the array itself as an example. Special attention will be given to the creation of the calibrator catalog and the high frequency observations, two areas i worked on extensively.
17/01/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — Critical Tests of Theory of the Early Universe using the Cosmic Microwave Background
Eiichiro Komatsu
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Abstract

The Cosmic Microwave Background (CMB), the fossil light of the Big Bang, is the oldest light that one can ever hope to observe in our Universe. The CMB provides us with a direct image of the Universe when it was still an "infant" - 380,000 years old - and has enabled us to obtain a wealth of cosmological information, such as the composition, age, geometry, and history of the Universe. Yet, can we go further and learn about the primordial universe, when it was much younger than 380,000 years old, perhaps as young as a tiny fraction of a second? If so, this gives us a hope to test competing theories about the origin of the Universe at ultra high energies. In this talk I review the present status and future prospects on our quest to probe the physical condition of the very early Universe.

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15/01/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — Intermediate-mass black holes in globular clusters
Nora Luetzgendorf (ESO Garching)

Abstract

The study of intermediate-mass black holes is a young and promising field of research and of high interest in modern astrophysics. If they exist, they could explain the rapid growth of supermassive black holes by acting as seeds in the early stage of galaxy formation. Formed by runaway collisions of massive stars in young and dense stellar clusters, intermediate-mass black holes could still be present in the centers of globular clusters, today. Our group has set out to investigate the presence of intermediate-mass black holes in globular clusters and study their properties. For a sample of 10 galactic globular clusters we measured the inner kinematic profiles with integral-field spectroscopy that we combined with existing outer kinematic measurements and HST luminosity profiles. With this information we are able to detect the crucial rise in the velocity-dispersion profile which indicates a central black hole. In addition, N-body simulations compared to our data will give us a deeper insight in the properties of clusters with black holes and stronger selection criteria for further studies. I present the current work of our group including the data compared to simple analytical models and detailed N-body simulations. For the first time, we obtain a homogeneous sample of globular cluster integral field spectroscopy which allows a direct comparison between clusters with and without an intermediate-mass black hole.
10:00, D30 | ESO Garching
Star and Planet Formation Seminar
Talk — ALMA's view of the initial conditions within a massive protocluster
Jill Rathborne (CSIRO Astronomy and Space Science, Sydney)

Abstract

Clusters are the building blocks of galaxies and the nurseries of most stellar systems. However, little is known about the formation of the most massive clusters. In recent surveys, one object, G0.25+0.02, stands out as extreme. Identified as a cold, dense, massive molecular clump devoid of current star-formation, it has exactly the properties expected for a clump that may form an Arches-like massive cluster. However, single dish data from the MALT90 survey reveal the presence of complex molecules and tracers of hot/shocked gas within G0.25+0.02, suggesting that its interior may be far from cold and quiescent. In this talk I will show and discuss the preliminary images and results from our recent ALMA cycle 0 observations of the 90 GHz continuum and line emission toward G0.25+0.02. We detect emission from a number of key tracers of the gas conditions (HCO+, HCN, SiO, SO, HNCO, H2CS, H13CO+). The data are spectacular and reveal, for the first time, the detailed kinematics and chemistry of the small-scale structure within this unique protocluster.
10/01/13 (Thursday)
16:15, Auditorium Telescopium (ESO HQE, Garching) | ESO Garching
Munich Joint Astronomy Colloquium
Talk — The Most Massive Stars in the Local Universe
Paul Crowther (University of Sheffield)
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Abstract

The lower limit to the mass of stars is well defined, while the upper limit remains controversial. I shall summarise evidence in support of the currently accepted limit, and present recent VLT-based studies of the brightest members of young, nearby star clusters which argue for a higher limit. Consideration is given to questions of binarity using a variety of methods, while we present simulations of star clusters which argue for an upper mass limit close to 300 solar masses. The wider significance of this limit is discussed both for the integrated properties of unresolved star clusters and the possibility that pair-instability supernovae exist in the local universe, as proposed for SN 2007bi.

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08/01/13 (Tuesday)
12:30, D29 | ESO Garching
Lunch Talk
Talk — A physical interpretation of the structure of molecular clouds
Joerg Fischera (CITA, University of Toronto, Canada)

Abstract

The origin of the initial mass function of the stars is still poorly understood but it is believed that it is directly linked to the complex structure of molecular clouds. Observations indicate that the star forming process is predominantly related to filamentary structures. I will show that filaments of low mass-line density are consistent with pressurized isothermal self-graviting cylinders and can therefore be used to infer the distance, the pressure of the surrounding medium, and (for known distance) an independent measurement of the emission properties of dust grains in the molecular phase. I will discuss basic aspects and provide a physical interpretation of the observed statistical properties of star forming and non-star forming clouds which suggest a separation into two different components related to a turbulent medium and self-gravitating pressurized condensed structures.