Seminars and Colloquia at ESO Santiago

Wolf-Rayet (WR) stars are characterized by bright and broad emission lines in
their optical spectra. Those lines give evidence for strong stellar
winds. The quantitative analysis of such spectra requires adequate
non-LTE model atmospheres, which account for the absence of local
thermodynamical equilibrium and the atmospheric expansion.

State-of-the-art model atmospheres, such as the Potsdam Wolf-Rayet
(PoWR) code, can reproduce the observed WR spectra sufficiently and thus
allow their reliable analysis. The results confirm that WR atmospheres
are composed mainly by helium and nitrogen (WN types) and by helium,
carbon and oxygen (WC and WO subtypes). A subgroup of WN stars also
contain more or less hydrogen, while all other WR stars are hydrogen
free. Models for the evolution of WR stars thus have to explain how the
hydrogen-rich envelope has been lost.  

The WR populations of the Milky Way, the Magellanic Clouds, and some other
nearby galaxies have been analysed comprehensively. The comparison with
stellar evolution tracks reveals yet poor agreement, and demonstrates
a strong dependence on the metallicity of the respective population. 

Interesting questions refer to the physics of the mass loss. As for
other hot stars, radiation pressure is probably the main driving force.
Such stellar winds are obviously inhomogeneous, which implies questions
on the precision of empirical mass-loss rates, and is also relevent for
the unsettled problem how such stars generate their X-ray emission.

The feedback of hot massive stars by their ionizing radiation and
wind has a strong impact on their environment, creating circumstellar
nebulae and driving the evolution of their parental clusters. 

Meteorites have long been considered to reflect the compositional diversity of main belt asteroids and consequently they have been used to decipher their origin, formation and evolution. However, while some meteorites are known to be sampling the surfaces of metallic, rocky and hydrated asteroids (about 1/3 of the mass of the belt), the low-density icy asteroids (C-, P-, and D-types), representing the rest of the main belt, appear to be unsampled in our meteorite collections. In this talk, I will present evidence that the surface compositions of these icy bodies are compatible with that of the most common extraterrestrial materials, namely anhydrous interplanetary dust particles (IDPs), and I will put this result in the context of our current understanding of the early dynamical evolution of the solar system. In the light of this association between icy asteroids and IDPs, I will further re-examine the composition of the Themis collisional family of asteroids, and discuss the early thermal evolution of the parent body of this family.

Books and periodicals from the ESO Library at La Silla will be on display to be acquired for a reasonable price.  All the collected money will go to the Solidarity group.

On Thursday, books will be arranged at the Urania room and the Book Fair will be open to public (ESO & ALMA Science staff and teachers/students of advanced Astronomy of neighbour institutes) from 10:00 - 16:00 hr

A significant fraction of what we know about stellar properties depend on stellar associations, since they are open windows to understand stellar evolution. Specifically, they allow us to understand the change with time and mass. Thus, they are our laboratories where different theories can be tested. However, age is a key parameter and its estimation is not an easy task. A overview of the different methodologies will be presented, focusing on open clusters, moving groups and star forming regions, and their validity and limits will be discussed.

Classical Cepheid variable stars are crucial extragalactic distance tracers and high-sensitivity probes of stellar astrophysics. Understanding the systematics involved in the determination of Cepheid distances is an important step towards the long-term goal of measuring the Hubble constant with 1% accuracy, which will be a milestone towards understanding dark energy. At the same time, Cepheids enable tests of mixing processes inside stars such as convective core overshooting or rotation.

Here I present recent high-precision studies of Cepheid pulsations based on photometric, spectroscopic, and long-baseline interferometric observations that are currently opening new windows to study the previously unknown complexity of Cepheid pulsations. Specifically, I show examples of modulated light curves, discuss how modulated radial velocity curves affect the detection of spectroscopic binaries as well as the determination of Baade-Wesselink distances, and present first evidence for cycle-to-cycle differences in angular diameter variations.

I conclude by summarizing the impact of such irregularities on Cepheid distances and stellar astrophysics.

I review the progress and challenges we face in both observational cosmology- focusing on a strategy for understanding dark energy and testing our standard model of dark matter, and the high redshift Universe - focusing on the quest for the earliest galaxies and AGN and their possible role in governing cosmic reionisation. Impressive facilities are coming online in the next decade, including several dedicated to addressing these important questions. I discuss how we might prepare for this exciting era of discovery.

Lyman alpha (Lya) emitters (LAEs) provide our best opportunity to study low-mass galaxies experiencing active phases of star formation. They have been detected at any redshift. However,  their properties and the morphology of their Lyman alpha emission are not homogeneous. We used a sample of starburst galaxies in the local Universe, the Lyman Alpha Reference Sample (LARS), to study Lya in detail and relate it to rest-frame UV and optical emissions. Every galaxy in the sample that emits Lya does so by producing halos, more extended than UV continuum. Neutral hydrogen distribution and star-formation driven outflows happen to be a necessary condition for the escape of Lya photons. We, also, selected a sample of 2 < z < 4 LAEs in field surveys and the sample of the LAEs, narrow-band selected in proto-cluster fields at the same redshifts. Our preliminary results show that the intensity of the Lya emission line is related to the intensity of stellar lines, which represent the galaxy systemic redshift. Measuring the velocity offsets of low-ionization lines with respect to systemic redshift probes outflows due to galactic winds. I will address the role of outflows in the escape of Lya photons and the possible implications to LAE evolution.

Since its discovery, the little gas and dust cloud G2 (Gillessen et al., 2012; Pfuhl et al., 2015) has caught the attention of the astronomical community. Recent observations of the gas and dust cloud G2, discovered by Gillessen et al. (2012), have revealed that G2 has been experiencing its pericenter passage in the last months. Though no major interaction with SgrA* has been detected so far, G2 is expected to enter now a new evolutionary phase, in which the hydrodynamic interaction with the hot environment should play a dominant role. However, there is still a large debate on the nature and formation of the object and discriminating between the different scenarios will also help shedding light onto the evolution of G2 in the next years. The present contribution focuses on the investigation of "diffuse cloud" and "compact source" scenarios, where G2 is either a homogeneous clump or it is produced by the outflow from a mass-losing star. Previous 2D simulations (Schartmann, et al., 2012; Ballone et al., 2013) allowed us to get some constrains on the nature of the object. In addition to this, 3D AMR simulations now allow us to perform a more detailed and realistic comparison to observations and to study the full evolution of G2 in these two different pictures."

Recent observations have revealed various structures within the gravitational influence of Sgr A* that apparently defy the fundamental principles of star formation and stellar dynamics. On one hand, the red giants display a flat density profile, contrary to the cuspy one predicted by conventional stellar relaxation. On the other, Wolf-Rayet and OB stars are observed where in-situ star formation should have been prohibited by the strong tidal force from Sgr A*, and their spatial and phase-space distributions also contradict our understanding of stellar dynamics. To explain each of these features, many scenarios have been proposed, which render the model increasingly complicated. We suggest that the sub-parsec stellar disk surrounding Sgr A*, which was recently discovered, can reconcile all the above inconsistencies. We show that during the fragmenting past of this disk, the star-forming clumps could efficiently deplete red giants by repeatedly colliding with them. We also show that because of the torque exerted by the disk, stars within the central arcsec from Sgr A* would quickly mix in the angular-momentum space, which naturally explains the observed distributions of Wolf-Rayet and OB stars. Our results, imply that Sgr A* was fueled by gas and stars several millions years ago and could have been an energetic AGN.

In recent years it has been shown that galaxies are surrounded by stellar streams that are remnants

from past interactions (e.g. Mihos et al. 2005). These streams are invaluable fossils of the interaction

history of galaxies with their environment, providing a new and very powerful way of studying galaxy evolution.

In addition to cosmic gas accretion, every galaxy has an internal source of cold gas supply for fuelling ongoing star formation, namely the stellar populations themselves. We study the fractional contribution of recycled stellar ejecta to the star formation rate (SFR) and stellar mass of present-day central and satellite galaxies using a cosmological, hydrodynamical simulation from the EAGLE project. We investigate how these contributions depend on galaxy mass and type, and explore the relation with metallicity. We find that the importance of recycling increases steeply with galaxy stellar mass for stellar masses below 10^10.5 solar masses, and decreases mildly at higher mass. This trend arises from the mass dependence of feedback associated with star formation and AGN, which preferentially suppresses star formation fuelled by recycling. Furthermore, recycling-fuelled star formation exhibits a tight, positive correlation with galaxy metallicity, with a secondary dependence on the relative abundance of alpha elements. We predict that, for central galaxies with a mass similar to that of the Milky Way, the contributions of recycled stellar ejecta to the SFR and stellar mass are 35% and 20%, respectively.

The role of magnetic fields in the star formation process is a contentious matter of debate. In particular, no clear observational proof exists of a general influence by magnetic fields during the initial collapse of molecular clouds. Our aim is to examine magnetic fields and their influence on a wide range of spatial scales in low-mass star-forming regions. We trace the large-scale magnetic field structure on scales of 10^3-10^5 AU in the local environment of Bok globules through optical and near-infrared polarimetry and combine these measurements with existing submillimeter measurements, thereby characterizing the small-scale magnetic field structure on scales of 10^2-10^3 AU. For the first time, we present polarimetric observations in the optical and near-infrared of the three Bok globules B335, CB68, and CB54, combined with archival observations in the submillimeter and the optical. We find a significant polarization signal P>=2%, S/N>3 in the optical and near-infrared for all three globules. Additionally, we  detect a connection between the structure on scales of 10^2-10^3 AU to 10^3-10^4 AU for both B335 and CB68. Furthermore, for CB54, we trace ordered polarization vectors on scales of ~10^5 AU. We determine a magnetic field orientation that is aligned with the CO outflow in the case of CB54, but nearly perpendicular to the CO outflow for CB68. For B335 we find a change in the magnetic field oriented toward the outflow direction, from the inner core to the outer regions. We find strongly aligned polarization vectors that indicate dominant magnetic fields on a wide range of spatial scales.

Binary orbital motion causes a periodic variation in the path length travelled by light
emitted from a star and arriving at Earth. Hence, if the star is pulsating, the observed
phase of the pulsation varies over the orbit. Conversely, once we have observed
such phase variation, we can extract information about the binary orbit from
photometry alone. Recent space-based photometry has made it possible to measure
the orbital phase variation of pulsating stars in binary systems with extremely high
precision over long time spans. This variation also manifests itself in the Fourier
transform, as a multiplet with spacing equal to the orbital frequency.
We have developed two complementary methods for this problem: one, called the
FM method, dealing with modulation in the frequency domain (Shibahashi & Kurtz
2012), and the other, called the PM method, analyzing the phase modulation in the
time domain (Murphy & Shibahashi 2015).
These are achievable with the photometry alone, without spectroscopic radial
velocity measurements. We apply these two methods to Kepler mission data to
search for invisible binary companions in Kepler data, including planets and invisible
massive objects such as neutron stars and stellar-mass black holes.

20 years ago the first hot Jupiter was discovered, raising new questions on planetary formation and migration. The processes driving planetary migration involve either interactions with the gas disc or interactions with a third body (planetary or stellar). Determining if hot Jupiters can be found in multiple systems is one of the keys to determine the fraction of each migration mechanism.

Since 2008 the spectrograph CORALIE on the Euler Swiss telescope in La Silla is used for the follow-up of WASP transiting candidates. More than 120 hot Jupiters have already been confirmed. A long-term radial velocity survey of the WASP targets with a confirmed hot Jupiter has also been conducted with CORALIE. The aim of the survey is to find additional companions to hot Jupiters that could have played a role in the migration process.

I will first present the very peculiar WASP-94 system and describe the ongoing HARPS program that resulted from this discovery. Secondly I will present the recent discovery of the outer planets around WASP-41 and WASP-47.

The most massive galaxies in the Universe have attracted lots of attention in the recent years because of their dramatic metamorphosis from being tiny star forming protodisks at high-z to huge quiescent spheroids in the nearby Universe. In order to undergo this transformation they must grow in an inside-out fashion, but cosmological dimming prevents us from a direct test on that scenario because of its strong dependence with redshift - (1+z)^4 -. To this end we have analysed in extreme detail the 6 most massive (Mstellar > 5x10^10MSun) elliptical galaxies at z < 1 in the HUDF12. Because of the extreme depth of these images and the careful data reduction, we are able to trace the galaxy surface brightness profiles up to the same levels as in the local Universe but at <z> = 0.65 (31 mag arcsec^2in all 8 HST bands, ~29 mag arcsec^2 restframe or beyond 25 effective radii). This fact enables us to investigate the galactic outskirts or stellar haloes at a previously unexplored era, characterising their light and mass profiles, colors and for the first time the amount of mass in ongoing mergers.

I will discuss recent results on the magnetic field characteristics of massive stars obtained by various 
surveys. Magnetic fields influence many stages of stellar formation and evolution.
Observations of massive stars indicate that the presence of magnetic fields is responsible for a wide range
of phenomena, such as chemical peculiarity, periodic UV wind-line variability, cyclic variability in H alpha 
and He II 4686, excess emission in UV-wind lines, and unusual X-ray emission.
A magnetic mechanism was proposed for the collimated explosion of massive stars, relevant for
long-duration gamma-ray bursts (GRBs), X-ray flashes (XRFs),and asymmetric core collapse supernovae.
The significance of magnetic field studies is further emphasized by a large numberof important, but as yet
not fully solved fundamental astrophysical problems, such as the mechanisms of magnetic field generation
and the impact of magnetic fields on stellar activity in stars of different spectral classes.

Mergers appear as a normal phase in the history of the galaxies, the detailed analyses of our sample revealed the importance of merger processes, including their remnant phases. Together with the large evolution of spiral properties, this points out the importance of disk survival and strengthens the disk-rebuilding scenario. The last 5 years we have applied our scenario to local galaxies and in particular to M31. Among the result of our simulations, we pointed out that the first tidal tail goes toward the location of the Milky Way. TDGs expelled from this ancient merger were used to reproduce the Magellanic Stream, we have called 'ram-pressure plus collision' scenario. The corresponding hydrodynamical modeling provides the currently most accurate reproduction of the whole HI Stream morphology, of its velocity, and column density profiles along L_MS.

Identifying feedback mechanisms responsible for the rapid quenching of star formation occurring in the early stages of the evolution of massive galaxies is crucial for advancing our understanding of galaxy formation and evolution. The discovery of massive and extended molecular outflows in several nearby galaxies constitutes a major breakthrough in this field. Because cold and dense molecular gas is the primary ingredient of star formation, massive molecular outflows are presumably extremely relevant to galaxy growth and evolution.

Our observations have shown that, although molecular outflows can develop also in purely star forming galaxies as a consequence of stellar feedback, the presence of a powerful quasar can significantly enhance mass-loss rate, kinetic power and momentum rate of the outflows, thereby resulting in a more profound feedback on the host galaxy. The high outflow momentum rates (~20 L_AGN/c) estimated in AGN host galaxies support models of ``energy-conserving’’ outflows, generated by hydrodynamical coupling of the AGN with the galactic interstellar medium via fast and highly ionised nuclear winds.

Feedback can be even more dramatic at high redshift. Our high sensitivity interferometric observations of the [CII]158micron emission line and FIR continuum in the quasar SDSS J1148+5251 at z=6.4 have revealed a giant (r~30 kpc) outflow of cold gas reaching a velocity of ~1500 km/s. Comparison with simulations shows that, although the quasar is likely the main driver of the outflow in SDSS J1148+5251, supernova feedback must play a prominent role, as supported by our discovery of intense star formation occurring at least up to scales of r~10 kpc in this z>6 quasar host galaxy.

I discuss the variable star population and the structure
of the horizontal branch of the distant globular cluster
(GC) NGC 6229, where we found 25 new variables, among them
fifteen RR Lyrae, six semiregular, and one SX Phoenicis.

I use this cluster to present our time-series CCD photometry
of globular clusters programme, in which we employ Difference
Image Analysis (DIA) to extract very precise light curves
even in the crowded central regions down to V = 19 mag.
The observations are carried out mainly with 2m-class
telescopes. We have discovered more than 200 variable stars
in a sample of 19 selected GCs and have, therefore, updated
the census of variables in each system having, in some cases,
actually completed it down to a certain magnitude.
The absolute magnitude and metallicity for each individual
RR Lyrae are obtained via the Fourier decomposition of its
light curve. An average of the these parameters leads to the
distance and metallicity of the host GC. I present the
mean [Fe/H] and distance for a group of selected GCs based
exclusively on the RR Lyrae light curve Fourier
decomposition set on a homogeneous scale.

I shall present a survey of my scientific activity after 44 years,
in the fields of the galactic evolution from high-dispersion
spectroscopy of F to M-type stars, then in the dynamics of clusters
and superclusters of galaxies. I shall also give some infos concerning
astronomy outreachs.

I will split the presentation in two distinct parts. In the first one, I will summarise the results we obtained via a sub-parsec resolution hydrodynamical simulation of a Milky-Way like galaxy, in the context of gas accretion, star formation, the role of bars and the dynamical impact of the central black hole. In the second part, I will describe the recent outcome of a small campaign (with GMOS) aimed at improving our understanding of the origin and evolution of low-mass galaxies, then shifting to a preview of what we got so far with a dedicated MUSE GTO programme focusing on the most massive end of the galaxy population.

I will present the results of two complementary Brown dwarf Atmosphere Monitoring programs (BAM-I & II) aimed at characterizing planetary temperature sub-stellar L, T, and Y-dwarfs. The BAM-I project uses the SofI instrument on the 3.5 m New Technology Telescope to conduct an extensive near infrared monitoring survey of an unbiased sample of 69 brown dwarfs spanning the L0 and T8 spectral range, with at least one example of each spectral type. A total of 14 brown dwarfs were identified as variables with peak-to-trough amplitudes ranging from 1.7% to 10.8% over the observed duration. Approximately half of the variables show monotonic sinusoidal amplitude variations similar to 2M2139, and the remainder show aperiodic variations similar to SIMP0136. The survey was designed to test the hypothesis that the L/T transition is a region of a higher degree of variability due to the presence of patchy clouds. In the BAM-II project we conducted a pilot study monitoring an initial sample of five ultracool T6.5 to Y0 brown dwarfs for infrared photometric variability using the SWIRC camera on the 6.5m MMT. Late-T brown dwarfs with temperatures ranging from 500 – 900 K are expected to have salt and sulfide clouds form and breakup. We are currently following-up all our candidate variables with multi-wavelength monitoring using a variety of ground-based telescopes. These brown dwarf variables will provide an invaluable dataset that will serve as a benchmark comparison to directly imaged planets and intensely irradiated Hot Jupiters and to synthetic atmospheric models incorporating different physical processes.

The Gaia-ESO Survey is the largest high-precision study specifically designed to cover the Gaia range of 
stellar populations. It will provide the first homogeneous overview of the distributions of kinematics and 
elemental abundances in the Milky Way. 

This large public spectroscopic survey, targeting more than 100,000 stars, is now in its fourth year of
observations. Over 30 articles are already published covering the chemical distribution of the Thick and 
Thin Disks, newly determined parameters for young to old Open Clusters, and searching for metal-poor 
stars in the Bulge and Halo. In this overview I will describe the survey in more detail and present the 
science highlights of the survey thus far. 

HAT­South is a ground-based transit survey and is the first one capable of 24h continuous coverage. The survey has already detected more than a dozen of new transiting exoplanets and many are the ones to come. In this talk I will present the discovery of two new planetary systems: HATS-15 and HATS-16. Both the systems are composed by two massive hot Jupiters (~2.17 Mjup and ~3.27 Mjup respectively) orbiting around relatively old main-sequence stars. In particular, HATS-16 is slightly active, showing a photometric modulation consistent with a rotational period of 12 days. This fast rotation, might be the result of a star-planet tidal interaction.

While almost 1100 cataclysmic variables (CVs) have published orbital periods (Ritter & Kolb 2013),
relatively little is known about their accreting white dwarfs (WDs). The effective temperatures (Teff)
of WDs are a direct measure of the accretion rate, averaged over the thermal time scale of their
envelopes and hence provides a vital insight into the fundamental properties governing the long-term
evolution of CVs. At present, only ~45 systems have reliable Teff (Townsley & Gaensicke 2009).
To increase the number of object with an accurate Teff measurement is essential to deepen our
knowledge of CV evolution and we have been awarded a large HST program in Cycle
20 (122 orbits, Gaensicke 2012), in which we obtained high-resolution ultraviolet spectroscopy of
40 CV white dwarfs with the Cosmic Origin Spectrograph (COS).
I will discuss the observations and data analysis and present results from this large campaign aimed to
investigate the physical properties of cataclysmic variables white dwarfs.

Astrobiology has become the meeting point for Astronomers, Biologists, Geologists, and Climatologists interested in putting together the puzzle of how life originated in the Universe.  Each year since the discovery of the first extra-solar planet of a Solar-type star (51 Pegb), almost 20 years ago, humanity is one step closer to the discovery of the first Earth-like planet in the habitable zone of its parent star, and the road-map leading to discovery of exolife has already been sketched by the world’s major agencies.

A real armada of space missions is already scheduled to launch in the next decade such as JWST, TESS, CHEOPS, and PLATO. Ground-based telescopes in Chile, on the other hand, are deploying a powerful new suite of instruments designed to find and characterise exoplanets, such as GPI in Gemini, and ESPRESSO and SPHERE at the VLT. Additionally, Chile concentrates several extreme environments like the driest desert and areas with the largest density of thermal sources in the World, targeted by Astrobiologists in Biological and Geological Sciences.

Chile is becoming one of the major poles of astrobiology worldwide with active research groups at several major universities and observatories. An important activity of the astrobiology community in Chile is the organisation of a major biennial symposium of astrobiology in Chile bringing together astronomers, biologists, geologists, and climatologists from all over the world to discuss the most recent progress in the quest for exolife. AstroBio 2015 is the third symposium of this series.  The main aims of this symposium will be to:

1.      Bring together the major astrobiology groups from the World and their South American counterparts

2.      Foster exchanges across all the major disciplines involved in the field of astrobiology and in particular people working on climatology of Solar System planets;

3.      Include a strong parallel outreach program aimed at informing the public about this relatively new discipline with the participation of the main experts in the world in the various disciplines.

Conference email: astrobio2015@eso.org

Organizers: ESO, Universidad de Chile, Universidad Andrés Bello

The ESA cornerstone mission Gaia launched on December 19th 2013 will revolutionise astronomy observing objects as diverse as minor planets, stars, galaxies out to QSOs and impacting almost all areas of astronomy. In my talk I will present our ongoing effort to fully exploit Gaia data, complementing them with ground-based near-infrared surveys and dedicated observations, to hunt peculiar benchmark ultra-cool dwarfs. The aim is to fill the current gaps in the mass-age-metallicity parameter space, and thus extensively test and improve the current model grids.

Resolved stellar spectroscopy presents us with "archaeological" evidence about chemical enrichment processes back to the earliest times. In this talk I will review the very early (chemical) evolution of the Milky Way. In particular, I will discuss our understanding of the origin of the peculiar abundance patterns in various subclasses of extremely metal-poor stars, taking into account new data from abundance and radial velocity monitoring programs. I will subsequently discuss the implications of these results for our understanding of the formation and early evolution of both the Milky Way halo and the satellite dwarf galaxies therein. I conclude with an outlook into the upcoming results from our program on the Canada-France-Hawaii Telescope to study this intriguing epoch much more efficiently.

While the main ground-based optical multi-object spectrographs obtain spectra of a few tens of objects at a
time, the panoramic integral-field ability of the new VLT/MUSE spectrograph increases that number by an 
order of magnitude. MUSE observations of HST deep fields yield a wealth of new spectroscopic 
identifications, revealing faint emission-line galaxies not detected in deep broad-band images. Here, we 
have combined the performances of the MUSE spectrograph together with the power of gravitational lensing 
by Frontier Fields galaxy clusters to offer a unique magnified view of the distant Universe. With a field of 
view of 1x1 square arc minutes over the full 4750-9350Å wavelength domain, MUSE enables redshift 
measurements of numerous lensed galaxies in the cluster core, and in particular of tens of multiple-imaged
 systems. Those spectroscopically-confirmed multiple-imaged systems are further used as strong 
constraints to improve the cluster mass model and reach a level of precision in the mass distribution only 
achievable with the joint use of extremely deep HST images and deep MUSE spectroscopy. In addition, 
strong gravitational magnification in the core of lensing clusters allows to probe the faint-end of the galaxy
luminosity function up to very high redshift. With MUSE we are capable of confirming faint candidate 
dropouts at z~5-7 through Lyman-alpha emission and identify additional emitters with high equivalent width,
fainter than the depth of the Frontier Fields Hubble images. Combined with similar deep exposures taken 
with MUSE in blank fields, this gives us the best opportunity to probe the Lyman-alpha luminosity function 
over a wide range in luminosity. 

The star-formation activity of our Universe increased from early epochs (z~6), peaked around z=2, and then decreased by an order of magnitude until present age. To fully appreciate the physical origin of the star-formation activity of our Universe we need to focus on the gas content of galaxies over cosmic time. The most recent versions of cosmological models of galaxy formation explicitly include the detailed tracking of the atomic and molecular hydrogen content of galaxies and make predictions for the sub-mm lines emission from species such as CO, HCN, [CII]. New semi-empirical approaches provide data-driven predictions for the atomic and molecular gas content of galaxies. I will discuss the predictions made by these different types of models for the HI and H2 content of galaxies and their sub-mm line emission. These predictions include a weak evolution in the HI content and HI mass function of galaxies, strong evolution in the H2 content of galaxies, the weak evolution in the cosmic density of HI, the evolution of atomic and molecular gas in dark matter haloes, CO SLEDs of galaxies over cosmic time, and predictions for CO luminosity functions. I will compare these predictions to current observational samples, discuss future observing strategies, and will also demonstrate how the combination of cosmological and semi- empirical models can help to reveal caveats in our understanding of galaxy formation.

The chemical abundances of the photospheres of stars reveal the
composition of their the birth environment; studying stars of different
ages, therefore, gives information about the chemical enrichment history
of the galaxy in which they dwell. The Sculptor dwarf spheroidal galaxy is
a well studied system in the Local Group, dominated by an old stellar
population (>10 Gyr), and does not appear to have experienced any episodes
of star formation over the last ~ 6 Gyr. Sculptor's star formation
history and chemical abundances are well known, making it the ideal target
to study chemical evolution. Here, I present new abundance measurements
for both sulphur in this galaxy and the first observed carbon-enhanced
metal-poor (CEMP) star in Sculptor.

I will review the status of the development of the SKA in Australia covering the development of the Murchison Radio-astronomy Observatory and the two SKA precursor telescopes - the Murchison Widefield Array (MWA) and the Australian SKA Pathfinder (ASKAP). I will also review the development of the new International Centre for Radio Astronomy Research (ICRAR) covering its research and technical programs and connection to the Pawsey Supercomputer Centre. Finally I will discuss an exciting new search for Dark Matter made possible with the low frequency capabilities of the SKA.

In my talk I will present the first results from a large observing campaign focused on the stellar populations in globular clusters using the recently commissioned integral field spectrograph MUSE. We are going to target about 30 clusters in the Milky Way, of which some have already been observed during commisioning and in GTO time. Using the technique of crowded field spectroscopy that we developed, we can resolve several thousand stellar spectra in a single datacube of the highly crowded cluster centres - as an example, about 90 minutes of observations on NGC 6397 yielded ~24,000 spectra of >12,000 stars, with a large fraction well below the main-sequence turnoff. Dedicated analysis tools allow us to determine radial velocities and stellar parameters for most stars in this sample. This will help us to better understand kinematics in globular clusters as well as their chemical compositions. In addition, multi-epoch observations will provide us for the first time with constraints on the distribution of binary periods inside the clusters.

Soon after the first exoplanets were detected it
became clear that the frequency of orbiting giant planets
is higher for metal-rich stars. The same clear trend has
not been found for lower mass planets. An extensive
observational program has been set up to use HARPS in
order to detect lower mass planets around metal-poor stars.
In this talk I will discuss the results as of yet for this
program.

Paul will present a few slides concerning CRIRES plus at morning coffee.

After a general introduction on superluminous supernova
 (SLSNe), I will present imaging and spectroscopy of a
 hydrogen-poor SLSN discovered by the intermediate Palomar
 Transient Factory: iPTF13ajg.  At a redshift of z=0.74,
 derived from narrow absorption lines, iPTF13ajg peaked at an
 absolute magnitude M_u(AB)=-22.5, one of the most luminous
 supernovae to date. We detect narrow absorption lines of
 MgI, MgII and FeII, associated with the cold interstellar
 medium in the host galaxy, at two different epochs with
 X-shooter at the VLT. From Voigt-profile fitting, we derive
 the column densities log N(MgI)=11.94+-0.06, log N(MgII)
 =14.7+-0.3, and log N(FeII)=14.25+-0.10.  These column
 densities, as well as the MgI and MgII equivalent widths of
 a sample of hydrogen-poor SLSNe taken from the literature,
 are at the low end of those derived for gamma-ray bursts
 (GRBs), whose progenitors are also thought to be massive
 stars. This suggests that the environments of SLSNe and GRBs
 are different, which is in contrast to the results of a
 recent study comparing the host galaxies of SLSNe and GRBs
 in emission.

The quantitative spectroscopy of individual massive stars in galaxies provides, among other things, stellar chemical abundances, representing a more accurate constraint of the present-day metallicity of star forming galaxies than the widely used HII regions, which are significantly affected by systematic uncertainties not well understood.

The combination of efficient multi-object spectrographs, sophisticated model atmosphere codes, and advanced analysis methods made individual massive stars in a significant volume of the local universe accessible to quantitative spectroscopy, including objects in galaxies well beyond the Local Group.

In this talk, I will review how the field of “Extragalactic Stellar Astrophysics” has matured over the last 10 years, as well as present my particular view on the challenges and prospects for the future.

The increasing number of gas detections in debris disks has the potential to change our understanding of the early evolution of planetary systems. ALMA Band 7 observations suggest that CO gas in the β Pictoris disk is of secondary nature, i.e. originating from exocomets. Indeed, the high planetesimal collision rates expected due to planetary resonances/impacts are able to release the ices that formed on their surfaces during the protoplanetary phase of evolution. This exocometary gas is fundamental to probe the ice component of planetesimals around the crucial time of delivery to the young terrestrial planets. In this talk, I will focus on new ALMA Band 6 observations of the β Pictoris disk, showing the power of ALMA multi-frequency, multi-array, multi-configuration, mosaic observations to derive 3D gas and dust properties in this remarkable system.

The formation of a star cluster (globular, nuclear) is typically associated with a rapid burst of star formation out of material with similar chemical composition. For this reason they are considered as time capsules for the most violent events during galaxy assembly. Finding more than one stellar population in these systems with a half-mass surface density of >1e3 M_sol/pc^{^2} (within typically 3pc or so), where stellar feedback is expected to be very efficient, suggests for an even more unexpected evolutionary path for them and their host galaxies. I will present observational evidences from various observing campaigns that allows us to trace back their formation and the assembly history of their host galaxy by using the sheer number of clusters, their structure, integrated age and metallicity distributions. The properties of one of the oddest compact stellar systems in a galaxy: the nuclear star clusters (some containing a massive black whole), are used to probe in situ and merging events in their and their host galaxy formation. Lastly, I will also outline our most recent ongoing observing projects that look into the most peculiar nuclear clusters with indications for the presence of a massive black hole.

Understanding the formation of clusters is important for cosmology and studying the evolution of galaxies.  At high redshift, z>1.5, we witness the early stages of cluster formation, and these structures are referred to as protoclusters.  The terms cluster and protocluster, while often used interchangeably, do not denote the same thing. Clusters are typically single virialised haloes, while protoclusters are the diffuse collection of haloes that will merge to make up the final low redshift cluster.  Using a semi-analytic model applied to the Millennium Simulation, I will demonstrate that protoclusters are very extended objects that are not necessarily dominated by one dark matter halo.  Additionally, I will explain the difficulties in obtaining a complete and clean sample of galaxies which is fundamental for estimating the size of the overdensity, and ultimately the final z=0 mass.

Ultra compact dwarf galaxies (UCDs) are dense stellar systems at the border between massive star-clusters and small galaxies. Recent research has shown that their average optical mass-to-light (M/L) ratio cannot be explained by stellar populations with a canonical initial stellar mass function (IMF). This can be understood if UCDs represent a case of rapid star formation in an extremely dense environment, leading to a top-heavy IMF. A top-heavy IMF implies a high number of neutron stars (NSs) in an aged stellar population, which could provide the unseen mass in UCDs. The NSs can form binary systems with a evolving low-mass stars and thereby become visible by X-ray emission. The frequency of such so-called low-mass X-ray binaries (LMXBs) depends on the frequency of NSs and thus on the IMF. The notion of a top-heavy IMF in UCDs can therefore be tested by modelling the frequency of low-mass X-ray binaries (LMXBs) in UCDs and globular clusters (GCs) and comparing it to the observed frequency of LMXBs. The observed frequency of LMXBs in UCDs in the Virgo Cluster does indeed support a top-heavy IMF in those UCDs. Further information will come from Monte-Carlo simulations of the LMXB-populations of UCDs and GCs in other galaxy clusters.

It is now firmly established that at least a significant fraction of
hydrogen-rich type II supernovae (SNe II) arise from red supergiant
progenitors. However, a large diversity of SN properties exist,
and it is presently unclear how this diversity can be understood
in terms of progenitor differences and pre-SN stellar evolution. In
this contribution, the full diversity of SN II optical light-curves
and spectra will first be presented and discussed. This will then be
used to show the large range of transient properties which need to
be explained in terms of pre-SN parameters, hence directly constraining
stellar evolution before explosion. The lack of a dominant population
of SNe with classic flat 'plateau' morphologies will be emphasised.
Various observational trends between SN parameters will be presented
and discussed in the context of red super giant progenitors. Finally,
the full diversity of SN II will be explored by presenting a number of
unusual and outlying events.

The distribution of stars by mass or the stellar initial mass function (IMF) that has been intensively studied in the Milky Wayand other galaxiesis the key property regulating star formation and galaxy evolution. The mass function of prestellar dense cores (DCMF) is an IMF precursor that has a similar shape, a broken power law with a sharp decline at low masses, but offset to higher masses. Results from numerical simulations of star formation qualitatively resemble an observed IMF/DCMF, however, most analytic IMF theoriescritically depend on the empirically chosen input spectrum of mass fluctuations which evolve into dense cores and, subsequently, stars. Here we propose an analytic approach by representing a system of dense cores accreting gas from the surrounding diffuse interstellar medium (ISM) as a spatial networkgrowing by preferential attachmentand assuming that the ISM density has a self-similar fractal distribution following the Kolmogorov turbulence theory. We obtain a scale free power law with the exponent that is not related to the input fluctuation mass spectrum but depends only on the fractal distribution dimensionalities of infalling gas (Dp) and turbulent ISM (Dm = 2.35). It can be as steep as −3.24 (uniform volume density Dp = 3) and becomes Salpeter (α = −2.35) for Dp = 2.5 that corresponds to a variety of Brownian processes in physics. Our theory reproduces the observed DCMF shape over three orders of magnitude in mass, and it rules out a low mass star dominated “bottom-heavy” IMF shapeunless the same steep slope holds at the higher masses.

Luminous quasars at high redshift provide direct probes of the evolution of supermassive black holes (SMBH) and the intergalactic medium (IGM) at early cosmic time. Over the last decade, numerous studies have established a sample of ~60 luminous quasars at z>5.5, selected using data from the Sloan Digital Sky Survey (SDSS) and the CFHT Quasar Survey. These studies have established the existence of SMBHs less than a Gyr after the Big Bang, and the presence of almost complete Gunn-Peterson absorption, indicating the end of the reionization at z~6. The discovery and characterisation of a statistically significant sample of bright quasars in this redshift range is crucial to further study this important era in the history of the Universe. The unprecedented sky coverage and depth of the Pan-STARRS1 (PS1) survey represents a fundamental step forward in building a complete sample of high-z quasar, and allowed us to more than double the number of z~6 quasars known in less then 3 years. Our new sample include quasars that are nearly a magnitude fainter that the SDSS ones and shows a variety of quasars properties, in terms of both luminosities and spectral features.

During the talk I will present new results from our search for high redshift quasars and our effort to understand the environment where supermassive black holes can form in the early Universe.

Dawn spacecraft entered the first science orbit around Ceres in late April 2015, starting its year-long mapping activity of this mysterious world.  Ceres, as the largest object located near the water ice-line in the current solar system, could hide clues about water transportation shaping the habitable Earth, as well as the process of the formation of outer solar system planets and icy satellites.  It may also holds secrets of the new category of objects in the asteroid belt that are actively outgassing, the so-called Main-Belt Comets.  However, little is known about Ceres after more than 200 years since its discovery, due primarily to its nearly featureless visible-infrared spectrum and lack of meteorite analogues.  Since approach, Dawn spacecraft has collected images of Ceres with resolutions down to 400 m/pixel so far.  Many spectacular features on the surface have been identified, such as bright spots, large scale lineaments, relaxed basins, and mysterious mons, all much more interesting than one could ever expect.  The study of Ceres is just beginning.  I will briefly introduce the background of Ceres, and discuss some early images of interesting surface features.

Chemical enrichment of the Galaxy, and ultimately of the Universe is caused by evolved stars. Nuclear fusion is producing heavy elements in their interior which are moved to the surface thanks to large convective motions. No scenario account for the the triggering of the mass loss of red supergiant stars (RSG) as they are not experiencing pulses nor flares. I will review our recent observations of the close environment of the nearest RSG stars Betelgeuse and Antares.

In my presentation I will give a short introduction to the science of extrasolar planets, in particular the technique of transit spectro-photometry. will describe my various projects in this emerging field using state of the art spectroscopic and photometric instruments on the largest ground based telescopes, the 'flying telescope' SOFIA (Stratospheric Observatory for Infrared Astronomy) and the Kepler and Hubble space telescopes.

For quite a long time we believed that the Earth occupied a privileged spot in the Universe. But now we know that we orbit a rather average star, located in the outskirts of a pretty conventional galaxy, not very different from the billions of galaxies that populate the Universe. In this talk I will describe the main discoveries that led us to this conclusion, highlighting the role that Paranal has played (and is still playing) in the quest to find our place in the Universe.

We present a study of the dynamical properties of 125 compact stellar systems (CSSs) in the nearby giant elliptical galaxy NGC 5128, using high-resolution spectra (R ≈ 26 000) obtained with VLT/FLAMES. Our results provide evidence for a new type of star cluster, based on the CSS dynamical mass scaling relations. All radial velocity (vr) and line-of-sight velocity dispersion (σlos) measurements are performed with the penalized pixel fitting (ppxf) technique, which provided σppxf estimates for 115 targets. The σppxf estimates are corrected to the 2D projected half-light radii, σ1/2, as well as the cluster cores, σ0, accounting for observational/aperture effects and are combined with structural parameters, from high spatial resolution imaging, in order to derive total dynamical masses (Mdyn) for 112 members of NGC5128’s star cluster system. In total, 89 CSSs have dynamical masses measured for the first time along with the corresponding dynamical mass-to-light ratios (Υdyn). We find two distinct sequences in the Υdyn-Mdyn plane, which are well approximated by power laws of the forms Υdyn ∝ M0.33±0.04 and Υdyn ∝ M0.79±0.04. The shallower sequence corresponds to the very bright tail of the globular cluster luminosity function (GCLF), while the steeper relation appears to be populated by a distinct group of objects which require significant dark gravitating components such as central massive black holes and/or exotically concentrated dark matter distributions. This result would suggest that the formation and evolution of these CSSs are markedly different from the “classical” globular clusters in NGC 5128 and the Local Group, despite the fact that these clusters have luminosities similar to the GCLF turn- over magnitude. We include a thorough discussion of myriad factors potentially influencing our measurements.

We are using data from the ESA Gaia mission to search for very fast transients and/or variability at optical wavelengths. The core mission of Gaia is mapping positions and brightnesses of stars down to G = 20 (V ~ 20.5). The data it produces consists of extremely accurate astrometry, mmag accuracy photometry on timescales of 4.4 seconds (10 datapoints on 44s) as well as hours and low-resolution spectra for all objects. The parameter space at these timescales is very poorly sampled in the optical, hence it is interesting to see what new phenomena we might discover.
An example of such fast optical transients are tidal disruption events (TDE) by intermediate-mass black holes (IMBH) (10^{^2} - 10^{^5} solar masses). Theoretical models (e.g. Lodato&Rossi, 2011) show that the time to maximum luminosity for a TDE scales with the square root of the BH mass. Moreover, the timescale to peak shortens as the disrupted object becomes more compact. For example, the timescale to peak luminosity when a WD gets disrupted by a 1000 solar mass BH is of the order of minutes. The accurate photometry on 44s timescales provides the possibility to resolve the rise of the lightcurve of such an event, allowing us to trigger detailed photometric and spectroscopic follow-up. The disruption of compact objects is especially interesting for finding IMBH, as the disruption of a WD by a SMBH will take place behind the horizon, hence will not produce an EM signal.

Because of the proximity, the Galactic Centre is a unique lab for studies of the interplay between stars, ISM and super massive black holes in galactic nuclei. The central 200 pc of the Galactic Centre includes 4x10^7 molecular clouds and has a star formation

rate of ~0.03 M/yr. Three young, massive and compact star clusters were found and includes around 100 massive stars, which strongly shape the nearby ISM. However, the massive stars beyond the clusters are still unknown. A complete census of these `field' massive stars have an important impact on our understanding of several fundamental astrophysical questions, such as 1) how molecular clouds form stars in this extreme environments, 2) initial massive function and 3) the stellar evolution models for massive stars in high metallicity environment. I will present our effort during these years to identify massive stars in the Galactic Centre and study their properties and origin. Our results show that massive stars pervade the Galactic Centre and they partly formed in situ and partly were ejected from the three clusters.

Understanding how the stellar evolutions move and evolve in different regions of galaxies is a key to understand the evolution of galaxies. Usually kinematics and stellar properties are obtained separately and unrelatedly, sometimes ignoring the other one. In this study we simultaneously obtain  kinematics, ages and metallicities of several stellar populations in the bulges of three different galaxies using high resolution IFS data.

The first exoplanet discovered around a Sun-like star changed our perception of planets both outside and inside our own Solar System. Now, 20 years after this groundbreaking discovery, we know that most stars in the solar neighbourhood host at least a planet, and that Earth-mass planets are the most abundant of all. This opens exciting new venues for research, and currently exoplanets is one of the main drivers for astronomical instrumentation development.
In this talk I review some of the key discoveries in the field, and Idiscuss  the path that is laid before us. I will focus on current instrumentation projects aiming at detecting at characterizing extrasolar planets, of which I highlight ESPRESSO, SPIRou, and NIRPS.

First Announcement
Chilean Exoplanet Community Focus Meeting

4th June 2015
European Southern Observatory
Vitacura Office
Alonso de Cordova 3107
Santiago, Chile

A variety of methods have so far been devised for discovering and characterizing extra-Solar planets.  Facilities situated in Chile for the observations of southern hemisphere skies, as well as the scientific community at various Chilean institutes have been crucial to the study of exoplanets.  The proposed one-day meeting here intends to provide a platform for scientists from all disciplines of exoplanetary research to learn about those diverse methods and techniques, as well as building partnerships and collaborations across institutes.
We invite all researchers across Chilean institutions to present their work here at ESO.  We hope that where there will be plenty of opportunities for discussions and cross-disciplinary exchange of ideas on the methodology of exoplanetary discovery and science.  We kindly request that you indicate your participation via a reply to this email, filling in the short questionnaire provided below.

Furthermore, an already ESO scheduled talk by Dr. Pedro Figueira from the Institute of Astrophysics and Space Sciences in Porto, titled "Twenty years of discoveries in Exoplanets: from the first planet to future instrumentation", will be included as part of our workshop.

We look forward to hosting many of you here at ESO.

Elyar Sedaghati
European Southern Observatory

As most stars are born in a clustered mode, young massive star clusters are the best places to find and study the formation and evolution of massive stars. R136 is one of the most massive nearby clusters in the LMC, which contains at least until now 72 known O and Wolf-Rayet stars. These young objects are usually embedded in dust and gas so that correcting the local extinction plays an important role for estimating the mass of stars. The extinction is derived for 26 O-stars in different HST filters using TLUSTY[3] atmosphere model for O-stars. Then we derived the mass and hence the Mass Function (MF) by multicolour photometry from HST data. We also simulated series of R136-like clusters using the Nbody6 code to test the segregation scenario for R136. thus we checked if massive stars tend to be formed locally at the center of a cloud or homogeniously. By comparing the surface brightness profiles (SBP) of simulated clusters mimicking R136’s SBP from HST data, we could determine which scenario is simulated the best R136. the results of these studies bring a new homogenious insight to the understanding of R136 and similar clusters in the light of future VLT and E-ELT high dynamic imaging observations at the diffraction limit in visible and IR wavelengths.

Abstract: During the late stages of their evolution, Sun-like stars bring products of nuclear burning to the surface. Most of the Carbon in the Universe is believed to originate from stars with mass up to a few solar masses. Although there is a chemical dichotomy between oxygen-rich and carbon-rich evolved stars, in the last three decades, a few stars have been shown to display both carbon and oxygen-rich material in their circumstellar envelopes. I will present observations and results of these mixed-chemistry objects using Spitzer, HST, UVES, VISIR, and SOFIA.

Code ROCHE enables robust modeling of multi-dataset observations of
close eclipsing binaries such as radial velocities, multi-wavelength
light curves, broadening functions, interferometric visibilities or
apparent positions in the case of resolved binaries. The code includes
starspots, eccentric orbits, asynchronous rotation, and third light. The
program makes use of synthetic spectra to compute apparent UBVRIJHK
magnitudes from the surface model and the object parallax. The surface
grid is derived from a regular icosahedron/octahedron to secure
more-or-less equal elements with observed intensities computed from
synthetic spectra for supplied passband transmission curves. All proximity
effects (tidal deformation, reflection effect, gravity darkening) are
taken into account. Integration of synthetic curves is improved by
adaptive phase step.
The code capabilities are documented on a few systems included
interferometrically resolved binary V923 Sco.

Be stars are the most rapidly rotating non-degenerate stars and their characteristic observables, emission lines and IR and radio excess, originate in purely gaseous, outflowing disks, whose evolution is governed by viscosity. We applied the viscous decretion disk (VDD) model, which currently explains most of observable properties of Be stars, to the case of a stable, tenuous disk surrounding the late type (B8Ve) beta CMi by the means of Monte Carlo radiative transfer modeling using the HDUST code (Carciofi & Bjorkman 2006, ApJ, 639,1081). The physical properties of the disk and the central star were determined by fitting the model observables to a large set of multi-wavelength (UV to radio) and multi-technique (photometry, spectroscopy, linear polarimetry, interferometry) observations. The results revealed a more complex density structure than expected for an isolated, steady-state decretion disk, which represents evidence for either non-steady decretion or the presence of an undetected binary companion tidally influencing the primary's disk. The binary hypothesis is supported by the modeling of radio flux measurements, which showed evidence for truncation of the disk, by several unexpected spectral features, and by an overall good agreement with the outcomes of smooth particle hydrodynamics (SPH) simulation of the influence of the possible binary orbit on the Be disk. Finally, we report on the diagnostic potential of the almost purely photospheric UV spectrum to constrain the polar radius and luminosity of the central star (2.8 R_sun and 185 L_sun), the linear polarimetry to constrain its rotation rate (W >~ 0.98, i.e., almost critical), and the interferometric shape extracted from VLTI/AMBER observations to constrain the inclination angle (43 degrees).

In this talk I summarize the results of more than 10 years of high-quality data obtained with UVES at VLT. We have detected very faint recombination lines (RLs) of C, O and Ne in Galactic and extragalactic H II regions that allow us to compute C, O and C/O radial gradients from RLs in the Milky Way and in other local group galaxies, such as NGC300. We have also determined C/O ratios from RLs in low-metallicity star-forming galaxies and I will discuss some of the implications of these results based on the comparison with chemical evolution models. I will also discuss the first results on an ambitious project aimed to the detection of extremely faint neutron-capture element emission lines in planetary nebulae to constrain the efficiency of the s-process and the convective dredge-up in the Asymptotic Giant Branch phase. Finally, I will make a picture of a new project devoted to accurate determinations  of C/O ratios from RLs in double-dust chemistry (DC) Galactic planetary nebulae.

Detecting the progenitor stars of different types of supernova (SN)
directly would require a census of stars in nearby galaxies.
Alternatively, the study of the environment once the supernova faded
has proved to be succesful in constraining the properties of their
progenitors. We used optical IFS of nearby SN host galaxies (0.005 < z
< 0.03) provided by the Calar Alto Legacy Integral Field Area (CALIFA)
Survey with the goal of finding correlations in the environmental
parameters at the location of different SN types. The total sample
consists of 128 SNe of all types in 113 galaxies. We focused on the
properties related with star formation and the SN environmental
metallicities, for which wide-field IFS enables proper comparisons of
different  approaches. In addition, we are also studying the coeval
parent stellar populations of nearby SNe in finer details (~tens pc)
with IFU spectrographs at several major telescopes including VLT, in
order to directly derive SN progenitor physical properties. I will
summarize the results from these two studies, and give prospects on
the future of the IFS of SN environments.

Imaging of planet formation in the act is now possible. Astonishing results in this direction are being achieved both with the direct detection in the near-IR of (forming) planets and with the high-contrast imaging of those protoplanetary disk features which are peculiar of planet-disk interaction. I will show some of our recent polarimetric high-resolution and high-contrast images of circumstellar environments obtained with VLT/NACO and discuss our prospects with VLT/SPHERE both at optical and near-IR wavelengths. These observations are setting higher standards for the planet and disk imaging and are revealing an ever-increasing diversity of frameworks for the planet formation. 

High-resolution spectroscopy is a powerful tool to inspect the atmospheres of both transiting exoplanets and
non-transiting ones. In my talk, I will first focus on the observations of the atmospheres of non-transiting hot Jupiters. I will briefly review the basics underlying the technique and present the most important results up to now. In the light of the three upcoming Extremely Large Telescopes (ELTs), i.e. the GMT, TMT and E-ELT, I will further present feasibility studies dedicated for the detection of oxygen in the atmospheres of Earth-like planets orbiting M-dwarfs.

Brown dwarfs - objects intermediate in mass between stars and planets - are ideal benchmark objects to test theories of star and planet formation. In particular, we hope to contribute to the understanding of the Initial Mass Function, the evolution of disks, and the physics of accretion. In this talk I will present results from a variety of observational studies focused on young brown dwarfs. I will show recent findings from our brown dwarf survey SONYC (Substellar Objects in Nearby Young Cluster), from IR and submm/mm observations of brown dwarf disks, and from variability studies aimed to constrain magnetic activity and accretion.

A workshop involving the Chilean supernova community, plus some collaborators from Argentina and
Japan. Tomorrow the workshop will start at ESO, then at Cerro Calan on Wednesday and finally 
Andres Bello (Campus La Casona) on Thursday.

The direct detection of reflected light from an exoplanet is, even in the most favourable cases, a 
herculean task, close to the detection limit of current observing facilities. In this talk, we will show 
how the Cross Correlation Function can be used to recover the minute reflected signal from an 
exoplanet in the optical (see Martins et al. 2013, MNRAS). We will also present the evidences for the
first direct detection of the optical reflected spectrum of 51 Peg on its orbiting planet, as well as how
this result can be used to tentatively infer some of the planet's characteristics as detaily described in
Martins et al.(2015, A&A, in press) .

Proto-clusters, the ancestor large-scale structures of present day galaxy clusters, are ideal laboratories to study dark matter assembly, cosmic baryon cycle, galaxy growth, and environmental impacts on galaxy evolution. I will first present the LCDM predictions for the physical properties and observational signatures of galaxy proto-clusters. I will talk about our ongoing efforts to search for z>2 proto-clusters in photometric and emission line galaxy surveys. Finally, we will put cluster progenitors in the context of cluster formation and galaxy evolution, highlighting their unique roles linking scales from large to small, and epochs form active star-formation to quenching.

This ESO workshop focuses on three interrelated topics: Satellites, Streams, and the Star Cluster-Dwarf Galaxy interface. The workshop aims at creating a bigger picture of how galactic satellites and tidal streams are interconnected within the framework of hierarchical structure formation. 

Galactic satellites give us an account of low-mass substructures at the present day. Tidal streams, on the other hand, are tracers of how these substructures disrupt and contribute to their host's assembly. Therefore, taken together, satellites and streams offer a unique opportunity to test and improve our understanding of structure formation — not just on small scales, but also on large scales by enabling us to measure the shape of the gravitational potential of their hosts.

However, satellite properties differ substantially. The discovery of transition objects at the star cluster -- dwarf galaxy interface has blurred the historical distinction between satellite classes, putting at question our understanding of tidal transformation and our census of small stellar systems. Exploring the star cluster-dwarf galaxy interface will be therefore an integral part of this workshop.

Stellar-mass black holes are by far the most massive objects in old stellar systems like globular 
clusters, nuclear star clusters and ultra-compact dwarfs. As such they quickly segregate to the center 
of a system and interact dynamically with each other and with the stars. Using direct N-body 
simulations and a hybrid approach, I study the dynamics of black holes and the consequences for
the stellar systems. In low-mass systems such as globular clusters, the segregation causes strong 
expansion of the cluster, leading to the extended clusters we observe in the outer halo, e.g., the 
Palomar clusters and NGC 2419. In the center of the low-mass systems, the black holes interact and 
eject each other until one or none is left. In dense, high-mass systems, the black holes grow through
tidal captures and tidal disruptions of stars while orbiting in the center of the systems and slowly
ejecting each other. However, in case the stellar system is dense enough, the stellar mass black 
holes can grow to intermediate mass to supermassive sizes before they can eject each other. I will 
present simulation results and discuss observational evidence for these findings.

In the past few years, the study of exoplanets has evolved from being pure discovery, then being more exploratory in nature and finally becoming very quantitative. In particular, transmission spectroscopy now allows the study of exoplanetary atmospheres. Such studies rely heavily on space-based or large ground-based facilities, because one needs to perform time-resolved, high signal-to-noise spectroscopy. The very recent exchange of the prisms of the FORS2 atmospheric diffraction corrector on ESO's Very Large Telescope should allow us to reach higher data quality than was ever possible before. With FORS2, we have obtained the first optical ground-based transmission spectrum of WASP-19b, with 20 nm resolution in the 550--830 nm range. For this planet, the data set represents the highest resolution transmission spectrum obtained to date. I will present our results, which show large unexplained deviations from planetary atmospheric models in the transmission spectrum redwards of 790 nm, indicating either additional sources of opacity not included in the current atmospheric models for WASP-19b or additional, unexplored sources of systematics. I will highlight our detailed analysis of the systematics present in the data and the careful estimation of planetary parameter estimation.

The Westerlund 1 Galactic cluster hosts an eclectic mix of
coeval massive stars. At a modest distance of 4-5kpc, it offers a unique
opportunity to study the resolved stellar content of a young (~5Myr)
high mass (5x10^4 Msun) star cluster. With the aim of testing
single-star evolutionary predictions, and revealing any signatures of
binary evolution, I shall discuss analyses of NTT/SOFI near-IR
spectroscopy of massive Wolf-Rayet (WR) stars in Westerlund 1. We find
that Nitrogen-type WR stars are H-poor compared to their counterparts in
the Milky Way field, and nearly all are less luminous than predicted by
single-star isochrones at the age of Westerlund 1. I will also present a
spatial analysis of the whole Galactic WR population - mapped using
stars in clusters such as Westerlund 1 to calibrate IR absolute
magnitudes. This has been used to test models of metallicity-dependent
stellar evolution, and to make predictions regarding the complete
Galactic WR star population that are of interest to spectroscopic surveys.

Angular and spectral resolutions are fundamental limitations for our understanding of the properties of galaxies in the nearby and distant Universe. A new generation of instruments and powerful observatories, as well as planned future facilities, is pushing the boundaries of resolving power over the entire electromagnetic spectrum. The advent of state-of-the-art facilities with high angular resolution and spectral resolution capabilities coupled with high sensitivity, such as ALMA, allows the interstellar medium and star formation properties of galaxies at intermediate redshift to be probed in unprecedented detail along with their local Universe counterparts.

A workshop to discuss the scientific results and upcoming opportunities afforded by these new capabilities is timely. What scientific and technical synergies are possible in the era of high-resolution studies of galaxies near and far?

The aim of this workshop is to bring together astronomers whose interests are furthering our understanding of star formation and interstellar medium processes at high spatial and spectral resolution. Emphasis on synergies between current and future facilities capable of carrying out such observations, particularly synergies with ALMA, and between the extragalactic and Galactic communities, will be encouraged. The workshop location and timing, a few weeks prior to the ALMA Cycle 3 proposal deadline, will provide a rich scientific environment with an emphasis on current and future ALMA capabilities.

Goal of the workshop

Exploration of the Solar system and subsequent discoveries are made with planetary missions and ground-based observatories. These two means are complementary from each other, and even sometimes strategically linked as in the case of the Deep Impact mission. Dedicated ground-based observation campaigns in support of planetary missions, as for Cassini-Huygens and Venus Express, have been successfully organised.
During this workshop, we expect to further explore the synergies between these two ways of exploring space, and to foster collaboration between both communities by sharing scientific and technical knowledge, needs, requirements, and techniques. Capabilities of major ground and space based observatories will be discussed. We will take advantage of the workshop location to showcase the current and future capabilities of ALMA for planetary science, and encourage planetary scientists to use this facility.

At the Photonics Lab of the Astronomical Instrumentation Group of U Chile we experimentally develop components for a low-cost fiber-based near-infrared heterodyne stellar interferometer. Our goal for the next time is to demonstrate the principle for one baseline using 1.55mu COTS fiber components, a ROACH board based correlator, and amateur telescopes. The motivation is to develop this then towards a science-relevant small or medium instrument to be used with any two or three telescopes. Because of the heterodyne approach this has then the potential to be extended to larger numbers of telescopes. In front of the vision of the internationally proposed Planet Formation Imager, the talk therefore proposes a pathway of developments which appear practical to be pursued using resources available here in Chile.