Glenn van de Ven will talk about variations in the IMF in early type galaxies and will highlight some of the outcomes of last week’s Lorentz Center workshop on this topic.

Despite (or because of) the wide astrophysical interest in this fundamental quantity, metallicity is vaguely and diversely defined, mostly hard to measure, and at times doubtfully derived. So let’s discuss it! Stellar nucleosynthesis, gas enrichment, galaxy emission lines, absorption lines, dust depletion, evolution with redshift: in this informal discussion we will touch upon some of the elements that play a role in our understanding of metallicity, from the Milky Way out to high-redshift galaxies. I work on the metal and dust content in the ISM of high-redshift galaxies, through absorption-line spectroscopy. In the audience there will be experts in stellar abundances, galaxy emission-line metallicity, electron-temperature metallicity, among other things. So bring your expertise! (and tomatoes)

I will outline the recipes of how to make dust evolution models that combine all that we know about dust formation and destruction in the ISM. One-dimensional evolution models constrained against observations at the present time reveal how interstellar dust content evolved with time and which dust sources dominated in different epochs of galactic evolution. I will highlight results from comparisons of such models with extragalactic observations with the Spitzer and Herschel Space Telescopes. Small scale variations of gas-phase element depletions in our own galaxy contain the information about cycling and processing of grains in different phases of the ISM. I will introduce a new three-dimensional model of dust evolution in the Milky Way disk that we use to interpret these observations and shed light on dust growth by accretion in the ISM, the key mechanism of dust formation in the local Universe.

During Filippo Fraternalis informal discussion two weeks ago on circumgalactic baryons, the issue of the so called "DLAs", i.e. self shielding HI clouds seen in absorption, was touched upon - and some interesting open questions were being raised. Several new results have in fact very recently helped towards understanding exactly how DLAs trace the assembly of matter, and the formation and evolution of galaxies and metals, through all cosmic epochs. DLAs are found both as "intervening" (host unknown) and as "GRB intrinsic" (host known to be a Gamma Ray Burst galaxy). Taken together, several surveys of those now form a detailed picture. Many current and former ESO students/fellows have contributed significantly to this work, and seen partly through their results I will provide a summary of the current state of the art.

Galaxies are devoid of most of the baryons that they should have given their dark matter halos. These baryons likely lie in the intergalactic medium still today in the form of a multiphase gas. In this discussion I will describe observational results and some theoretical expectation about the physical properties and the location of the gas around galaxies. I will also briefly discuss the gas flows onto galaxies from the external medium and their relevance for the growth of galaxies.

Dangerous cosmic weather forecast, in light of galaxy cluster mergers. I will discuss the causes of giant, cluster-wide tsunamis and tornadoes (e.g. shocks, turbulence), touching upon the theoretical framework for their formation as well as their observational effects

EPIC 204278916 has been serendipitously discovered from its Kepler/K2 light curve that displays irregular dimmings of up to 65 per cent for ~25 consecutive days out of ~79 days of observations. For the remaining duration of the observations, the variability is highly periodic and attributed to stellar rotation. The star is a young, low-mass (M-type) pre-main-sequence star with clear evidence of a resolved tilted disc. Such large and fast dips are rare and quite hard to explain. I will go through some possibilities to explain the observed behaviour in this star, hopefully generating a lively discussion on what is the true origin of these peculiar dips.

In this informal discussion, ASG will provide a summary of the status of the ESO Public Surveys, their data releases, and present the projects selected for the VISTA 2^nd round public surveys.  ASG will then provide an overview of the data published by the ESO Archive since February 2016. A short demo about quering, browsing and visualization of the science data products, to be facilitated by the newly deployed Aladin-lite interface on the Phase 3 query forms, will follow. ASG will also demonstrate 1)  the new service of the ESO catalog query interface, that allows the direct access of spectra products from a catalog record and support the exploration and retrival for spectroscopic data releases like Zcosmos and Lega-C, and 2) the use of the multi epoch photometry for the generation of light curves for variable sources. ASG will end with a forward look on the new archive services and user support.

Despite the general public's expectations -- that astronomy is a visual and colorful science -- the results produced at ESO can be often times inaccessible, due to the complex nature of the data. We at ePOD help delivering this complex and difficult data to the public, through artist's impressions, videos and animations.

With the 'Illustris zoom simulation project` it is possible to study the formation of baryonic halos in the Lambda-CDM cosmology with a 40 times better mass resolution than in the large-scale hydrodynamical simulation, Illustris. I here present the first results of zoom-in simulations of major mergers in a cosmological simulation carried out with the AREPO code. The galaxies from the high-resolution simulations have a bursty mode of star formation with a gas consumption timescale 10 times shorter than for normal star-forming galaxies. This burst mode is only present in the simulations with high resolution, and it hints that a too low resolution is the reason why the original Illustris simulation lacked a population of starburst galaxies (as shown in Sparre et al. 2015). I also show that a major merger between two spiral galaxies at z=1 usually destroys the stellar disks, but it is possible to regrow a significant disk component again before z=0.

Assuming a molecular cloud core forms stars at a low efficiency, the material can be distributed optimally amongst the stars. This is physically equivalent to a perfect model of complete self-regulated star formation and has important implications for the distribution functions such as the IMF and mass segregation. On a galactic scale, a similar argument can be used for the distribution functions describing star clusters which are forming freshly from the inter-stellar medium of a star-forming galaxy. The implications of this general approach are major, since it implies that the IMF on a galactic scale becomes dependent on the place and time where star formation occurs, with deep implications for galaxy evolution.

The majority of known Globular Clusters (GCs) shows homogeneity in 
the abundances of iron-group elements and in the heaviest of the 
α-elements. However there are several GCs which exhibit a significant 
spread in these elements. The origin of these anomalous clusters is still 
not fully understood.

By means of 3D  hydrodynamical simulations we tested a supernovae type II 
(SNeII) enrichment scenario for the formation of anomalous clusters. We 
found that this scenarion may be realized if in addition the dust can cool 
the gas and is consistent with observed anomalous GCs data 
if the initial masses of these GCs were higher at least by factor of ten than 
the current GC masses, or if  their IMFs were top-heavy.

This ID is meant to be a forum where we discuss the trends and needs associated with our own research work at ESO in terms of hardware and software. That includes the fact that datasets are becoming significantly bigger and reducing/analysing them more demanding in terms of CPU, RAM, disk space, etc.

We will very briefly present what is available for ESO scientists (Garching), and also what are typical individual request for resources we recently got. The floor will then be open for discussions, with the aim of getting a first glimpse of what we really need (just now, within the next 2 years, within the next 5 years). This input will also lead to a dedicated poll that will be launched soon after the ID, as to probe more objectively all ESO scientists in Garching.

The radio galaxy and merger remnant NGC 1316 is one of the most interesting galaxies in the nearby universe. Its population structure, its nucleus, its gas content, its dust content, its dynamics challenge attempts of conventional interpretations. I shall draw a general portrait of NGC 1316 with emphasis on recent MUSE data and their potential for providing a deeper understanding.

Protoplanetary disks are gaseous circumstellar disks surrounding newborn stars. Transitional disks are a class of protoplanetary disks with a big central gap or cavity. The most likely origin of the gaps in transitional disks is that they are opened by multiple planets inside. As suggested by their name, the conventional wisdom about transitional disks is that they are objects in transition between gaseous protoplanetary disks and gasless debris disks, and they mark the final stage in protoplanetary disk evolution. In this informal discussion, let us examine whether this conventional wisdom is a truth or a myth, by comparing the statistics of transitional disks with the occurrence rate of planets that are needed to open the gaps in them.

Thanks to the high-S/N afforded by MUSE data, it is possible to measure even
small variations for the strength of rather weak but IMF-sensitive features in the
optical spectra of galaxies.

I will present evidence for a systematic radial change in the slope of the initial-stellar
mass function, the precision of which is currently set by systematic differences between
reference stellar-population models, rather than by the data or their analysis.

My research is focused on the world of binary stars, which is characterised by a great diversity and richness. I will present some recent results obtained with various techniques, with an emphasis on the latest discovery with interferometry of a companion to the Luminous Blue variable HR Carina.

During a planetary transit, the planet acts as a “knife-edge” probe of the stellar surface highlighting brightness variations on the star and providing precise positional information about any starspots in the path of the planet. Since the transits are periodically repeating and Kepler provides continuous photometric coverage, the occulted spots are detected multiple times, and it is also possible to observe their emergence and decay. We are using this technique to perform detailed surface mapping of small-scale starspot features on distant stars in order to constrain dynamo properties of stars with a range of masses and rotation periods. We have identified discrete bands of starspots at well-defined latitudes on HAT-P-11, a K-dwarf star (0.8 Msun) with a solar like rotation period (~31 days). However, we detect more starspots than are visible at the Sun's maximum. This starspot pattern indicates that this low mass star with a slow rotation period has an alpha-omega dynamo in its interior, but the deeper convection zone may produce more or longer lived starspots. In addition, on Kepler-17, a more rapidly rotating (~12 days),  solar mass star (~1.0 Msun), we identify a rotation period for starspots at the equator that is faster than the mean rotation period of the star derived from spots at all latitudes. This is an indication of solar-like differential rotation.

Images of dust continuum and carbon monoxide (CO) line emission are powerful tools for deducing structural characteristics of galaxies, such as disk sizes, H2 gas velocity fields and enclosed H2 and dynamical masses. I will talk about a fundamental constraint set by the cosmic microwave background (CMB) on the observed structural and dynamical characteristics of galaxies, as deduced from dust continuum and CO-line imaging at high redshifts. As the CMB temperature rises in the distant Universe, the ensuing thermal equilibrium between the CMB and the cold dust and H2 gas progressively erases all spatial and spectral contrasts between their brightness distributions and the CMB. For high redshift galaxies, this strongly biases the recoverable H2 gas and dust mass distributions, scale lengths, gas velocity fields and dynamical mass estimates.  This limitation is unique to mm/submm wavelengths and unlike its known effect on the global dust continuum and molecular line emission of galaxies, it cannot be addressed simply. We nevertheless identify a unique signature of CMB-affected continuum brightness distributions, namely an increasing rather than diminishing contrast between such brightness distributions and the CMB when the cold dust in distant galaxies is imaged at frequencies beyond the Raleigh-Jeans limit. For the molecular gas tracers, the same effect makes the atomic carbon lines maintain a larger contrast than the CO lines against the CMB.

A major question in galaxy formation is how the gas supply that fuels activity in galaxies is modulated as galaxies migrate from the field into the group and cluster environment. A related question is how passive galaxies stay passive given that the Universe is full of gas and gravity works. I will address this question using a spectroscopic study of intermediate redshift field, cluster, and group galaxies. I will show that passive galaxies have higher gas contents in the field than in clusters or groups. This gas, when present, likely comes from a combination of accretion and stellar mass loss and is likely excited by preexisting stellar populations. I will discuss the evidence for and against this difference in the gas contents being a result of environmental effects. As part of this discussion I will give my point of view on how environmental studies of galaxy evolution need to not only show which processes are consistent with their observations, but also show which can be ruled out and which are required.

Understanding how the local massive elliptical at the center of most massive galaxy cluster formed and evolve is a particularly challenging problem. Searching for radio loud AGN has been particularly successful in the past to identify the progenitors of these galaxies out to redshift 5. From their SED, these galaxies exhibit large star formation rates, a massive and evolved stellar component, but also a radiatively efficient AGN. What is the evolutionary picture allowing to reconcile these extreme phases of growth in the overall galaxy evolution context? I will present the recent insights provided by ALMA observations and some of the future prospect about understanding how the radio loud AGN can impact the host galaxy evolution.

Over the past few years, several teams have advocated for the existence of "Obese black holes" at the centre of compact nearby galaxies. I will mainly focus on the most famous target, namely NGC 1277, to both discuss the science case itself, and to emphasise what I believe is a drift in the way we publish and advertise our science results. I will also take this opportunity to briefly mention a couple of items pertaining to the "publish or die" approach.

One of the future challenges of 30-meter class telescope will be the maintenance of the segmented primary mirror. On current smaller segmented telescope, for example the Keck, this ends up with an on-sky operation to replace the recoated segment. This is rather lengthy and results in a loss of scientific time. Alas one Keck “only” has 36 segment when a ELT will have 798 segment. The purpose of the phasing gun is to give a tool to the ELT that will avoid as much as possible on-sky operation and allow “quick phasing”. This discussion will address: What is the phasing gun? How does it work? What are the recorded performances so far?

RW Aur is a well known binary system of young stars, with the primary still surrounded by a disk. The primary star has always been considered as a prototype classical TTauri star, characterized by relatively small variability. Recently, the primary star underwent two major dimming events of more than 3 magnitudes, with the second one still ongoing. Among the possible explanation for this dimming there is the possibility that this is a result of the close passage of the secondary star few hundreds years ago having dynamically eject material along the line of sight, or the existence of a significant perturbation in the inner disk that is obscuring the star. In this discussion I will present the explanation we are carrying forward for this dimming. This is based on various optical, X-ray, and infrared observations, including an X-Shooter spectrum obtained during the still ongoing dim phase. Finally, I will relate this to the observations of other young stars where we might see scaled down versions of the same process.

We provide an overview of data products and science content of the ESO archive.

We describe the science data products published in the archive and how to access Public (query interfaces) and proprietary data products (via user portal account).

Alberto Micol will show ahow to access the science data products from the user portal account for Giraffe, Uves, Harps and Xshooter ESO in house processed data.

We then present very recent data releases: Laura Mascetti will present the content of the zCOSMOS and ATLASGAL releases published in January 2016, and Joerg Retzlaff will show how to access and download multi-epoch catalogs, i.e. light curves, from the recent VVV, VMC data releases, via the ESO catalog query interfaces.

We then present what is coming next: UltraVISTA DR3, Muse IDPs, Hawk-I + VIMOS imaging science data products. And VISTA DR4, VST DR3, Gaia ESO and PESSTO Dr3, VIMOS survey DR1 in 2016.

We conclude by showing recent statistics on the archive usage and the community that access ESO science data. You may wish to join it!

The gender(sex) dimension of science and technology has become one of the most important and debated issues worldwide, impacting society at every level. A variety of international initiatives on the subject have been undertaken, including continued monitoring of the status of women in science by Unesco or the annual reports “Education at a Glance” by OECD. The majority of the international organizations have made clear statements about their discrimination policies. Gender equality at large is one of the eight United Nations Millennium Development Goals, which clearly call for action related to science, technology and gender. But will we ever reach these goals? The pipeline still leaks, the glass ceiling is still in front/above us, we are still paid less ...

A very informal and open discussion, hopefully stimulated by selected highlights from recent international gender-summits and scientific meetings, as well as latest news/facts from the astronomical community, with a special eye on what we want/need/can achieve at ESO.

I will focus on the recent discovery of a very interesting white dwarf system that has: (i) an infrared excess from an orbiting dust disk; (ii) atmospheric pollution from accretion of circumstellar material; (iii) eclipses from six or more transiting objects, all within the white dwarf’s tidal radius; (iii) cool circumstellar gas, likely from collisions among the asteroids. I will also discuss how this object fit into our overall understanding of the fate of planetary systems around white dwarfs.