I will first give a short introduction on the APEX telescope and its instrumentation. I will then give an overview of the properties of the atmosphere at millimetre and submillimetre wavelengths and the implications for observing in this range. I will then introduce the observational techniques used to overcome the obstacles posed by the atmosphere: absorption and bright, highly variable sky emission, followed by a discussion on data reduction strategies with a focus on how to preserve extended structures particularly for continuum data, and its limitations. While the discussion is specific to APEX, most of the issues raised are also of great relevance for ALMA observations.

The Galactic Center is maybe one of the most violent regions for star formation in our Galaxy. It contains a large fraction of molecular material in the Central Molecular Zone, dominated by shocks, tidal fields and energetic input from massive stars, and possibly from the central black hole Sgr A*. I will discuss the latest observations to trace the conditions of the molecular gas that streams from the Galactic disk toward the Galactic Center region. An associated phenomenon may be the large scale "Fermi Bubbles" that appear perpendicular to the Galactic disk. The energy released from the constant supply of SNe might be enough to accelerate cosmic rays and a Galactic wind to explain the outflows.

I will illustrate the content of a book by Alvio Renzini and myself recently published by WILEY-VCH. The book is aimed at describing how stellar populations work, specifically regarding those tools commonly used to interpret the properties of galaxies in terms of their star formation history. The fundamentals on which these tools are constructed, as well as their limitations, are disclosed, so as to illustrate how much can be learned on galaxy formation and evolution from the analysis of the light from their stellar populations. After a summary of the content of the book, I will discuss in more detail two examples, one pertaining to the study of resolved stars in galaxies, and one to that of their integrated light.

The characteristic densities and radii of dark halos change systematically with the brightness of the galaxy. I will discuss how these properties are measured and our current understanding of the scaling laws. The fainter galaxies have smaller halos but their volume densities are higher. It turns out that the surface density of dark halos is almost independent of the luminosity of the galaxies. The scaling laws are related to the slope of the power spectrum of fluctuations in the early universe. (This work is in collaboration with John Kormendy)

Double bars in galaxies are a common but enigmatic phenomenon. They may occur in as many as 30% of barred galaxies, yet their origin remains unknown. The inner bars may be a relic of instabilities in the disc at its early stage of formation, when the disc was smaller, but they may also form from instabilities in a material accreted recently. I will describe, how efforts to confirm that the inner bar in a double barred galaxy rotates with a pattern speed different from that of the outer bar lead to a hypothesis of a counterrotating inner bar. Counterrotation of inner bar can well discriminate between hypotheses of its formation. I will also present methods to study such systems, and their predictions for the observed velocity fields, which can be confronted with datasets like Atlas3D. Establishing formation mechanisms of inner bars can lead to using them for tracking minor mergers or as probes of evolution of disks over Hubble time.

The Initial Mass Function is a function that gives the amount of mass locked up in a new generation of stars with masses in the interval (M,M+dM). It can be measured by counting the number of stars of different mass in newly formed star clusters. In other galaxies, where star clusters are not resolved, the upper mass end of the IMF is generally constrained using the Halpha to UV flux ratio sensitive to the emission of newly formed, massive stars. This technique, however, suffers from several major uncertainties mainly related to the extinction correction of both the UV and Halpha data and is based on the hypothesis that the star formation rate is constant on time scales as long as the age of the stars emitting in the UV, ie some 108 years. I will discuss how the recent claiming of a variable IMF strongly depends on the applied dust extinction corrections or on underlying assumptions on the star formation history of galaxies.

Most astronomy job announcements are coming out in the fall. The ESO fellowship application deadline is one of the earliest among many. This informal discussion is aimed to provide advice and help to PhD students and fellows who are looking for jobs. We'll discuss mostly postdoctoral type of jobs, applications and interviews. Participation from people, both fellows and staff, who went through the astronomy job hunting, and who wish to share their experiences is expected.

On Sept 30, 2011, ALMA has started Early Science Cycle 0 observations: the first science projects from external users were executed at the telescope. ALMA has chosen a phased approach to science operations, where the array is offered with partial capabilities as construction continues. Cycle 0 is thus just the dawn of the ALMA era. I will discuss what I think may be the highlights from the Cycle 0 collection of programs and will compare these with the ALMA science goals and the outlook on the wonders that are ahead of us. I will indulge on some celebration of the in-house successes and spend some time discussing the response of the European community. I will also try to provide some appropriate material for celebration.

In a time when statistics of millions of objects drives many science cases, things seem to move so fast that it is easy to lose track of the underlying physics. For example, why do the Sun and the Orion nebula show such different spectra? We shall remember how XIX century lab experiments can explain this. In general, with this informal discussion, I hope to refresh everyone’s memory about the basic physics behind astronomical spectra, that allows from measuring the metal abundances of the most distant galaxies to discovering extrasolar planets.

Real-time environmental measurements are required by many sectors of Chile´s economy; including mining, agriculture, and astronomy, as well as for meteorological and purely academic purposes. Our instrumentation group at the Universidad de Chile is currently working on three complementary projects that relate directly to this topic. In this talk I will describe a profiling water vapour radiometer being built that will be integrated into an autonomous weather station and deployed at Cerro Chajnantor. An open-hardware radiosonde transmitter/receiver pair is also being developed to allow for custom sensors to be tested and launched without requiring expensive hardware and its associated closed data processing software. Finally, an unmanned aerial vehicle, also based on open-hardware, will allow for atmospheric and geographical sampling on a footprint of several kilometres. Data from each of these instruments is complementary, and could be used to validate each other and even fill data gaps that might occur if one instrument was used alone. These robust data sets can be used to refine atmospheric models and provide valuable real-world boundary conditions for numerical weather prediction models, thereby increasing their physical relevance.

The General Relativistic model of cosmology (often referred to as Friedman-Lemaitre-Robertson-Walker model) has been the standard cosmological model for several decades and to many of us it seems quite familiar. Nevertheless, the interpretation and meaning of one of this model's central features - the expansion of the universe - is still a topic of confusion and controversy to this very day, as evidenced by a slow but steady trickle of publications. Points of discussion are: Are galaxies receding from one another because they are moving through space or because space somehow pushes them apart? Can galaxies recede faster than the speed of light? If so, can we see them? What is the fate of a galaxy that has been plucked from the Hubble flow? Is the cosmological redshift caused by the stretching of space or is it simply a Doppler shift?

We present spectroscopic data for 180 red giant branch stars in the isolated dwarf irregular galaxy WLM. Observations of the Calcium II triplet lines in spectra of RGB stars covering the entire body of the galaxy were made with FORS2 at the VLT and DEIMOS on Keck allowing us to derive velocities, metallicities, and ages for the stars. With accompanying wide field photometric and radio data we have computed the structural parameters of the stellar and gaseous populations over the full galaxy body. The stellar populations show an intrinsically thick configuration with 0.39 < q0 < 0.57. The stellar rotation in WLM is measured to be roughly 17 km/s , half that of the HI gas in WLM but significantly higher than what is seen from RGB stars in nearby dSphs. The ratio of rotation to pressure support for the stars is V/sigma ~ 1, in contrast to the gas whose ratio is roughly seven times larger. This, along with the structural data and close alignment of the kinematic and photometric position angles, suggest we are viewing WLM as a highly inclined oblate spheroid. Stellar rotation curves, corrected for asymmetric drift, are used to compute a dynamical mass estimate of 4.3 x 10^8 M_sun at the half light radius (rh = 1656 pc). Deriving relative ages for the stars allows the first investigation of the evolution of stellar velocity dispersions over four age bins spanning 12 Gyr. The velocity dispersion increases with stellar age in a manner consistent with internal feedback or substructure interactions producing the heating. The dispersion, mass, and scale length properties are consistent with WLM having not experienced strong tidal interactions in its past - at least relative to dSphs in the Local Group. These structural and dynamical constraints indicate that WLM has spent the majority of its lifetime in isolation, strongly suggesting that the extended vertical structure of its stellar and gaseous components and increase in stellar velocity dispersion with age is due to internal feedback, rather than tidally driven evolution. In contrast to the drastically different structure and dynamics between WLM and Local Group dSphs, we find they show very comparable metallicity distributions, and age-metallicity relations. We discuss how these similarities and differences may arise in the context of an evolutionary picture for Local Group dwarf galaxies. These represent some of the first observational results from an isolated Local Group dwarf galaxy which can offer important constraints on how strongly internal feedback modulates SF and dynamical evolution in low mass isolated objects.

At up to 300 nights, the Gaia-ESO survey is forseen to be the VLT's largest single program (co-PIs G. Gilmore and S. Randich), complementing the Gaia satellite's effort to understand the stellar content and the structure and formation history of the Milky Way. From my science angle (structure and dynamics), I'll go over core science questions, and what needs to be done to answer them in practice.

The informal discussion tries to address the efforts‭ – ‬past and future ones‭ – ‬made to explore whether biologically interesting material may exist in the solar system elsewhere‭ – ‬except on Earth.‭ ‬The search for such material has started decades ago and is still on-going with flying and planned missions.‭ ‬An attempt is made to explain what to look for,‭ ‬where to look for and which methods to use for detections and measurements onboard of space mission in the planetary system.‭

Most binaries have relatively small separations, with a peak in the separation distribution around 30 AU. But there is a distant tail with objects reaching separations of nearly one parsec. The binding energy of such very soft binaries is so small that they are vulnerable to disruption by passing stars, by molecular clouds, and by the Galactic tidal field. I will discuss recent efforts to find such extremely wide binaries, and the prospects offered by Gaia to identify all such pairs in the solar vicinity. The formation of very wide binaries has been a long-standing mystery, and I will mention results from some new numerical simulations (not completed, nor properly digested) which may cast light on the existence of ultra-wide binaries.

After their birth, stellar clusters remain for a few million years partially or totally embedded in the dusty gas in which they formed. An important part of the ongoing star formation in a galaxy can hence be undetectable in the visible. Observing these cluster early phases is a challenge and requires high resolution infrared and/or radio capabilities. After giving a general introduction on the subject of stellar clusters in galaxies, I will present and discuss VLT observations (ISAAC, VISIR and SINFONI) of three young very massive embedded cluster complexes in the central star-forming region of the heavily barred galaxy NGC1365.

High resolution spectra can be easily obtained for metal poor stars in the halo of the Galaxy, in globular clusters but also in dwarf spheroidal galaxies. From these spectra, detailed chemical abundances can be determined. I will describe the different steps which enable to convert these spectra into quantitative chemical abundances and present a comparison of the elemental abundances found in these different objects in the light of Galactic chemical evolution models. Finally, I will show recent results on the chemical composition of a sample of stars in the distant Globular Cluster Ruprecht 106 which reveal peculiar abundance anomalies.

It is foreseen that in the near future, we will be able to measure the light from extrasolar planets similar to the Earth. When these data become available, a truly inter-disciplinary approach to their analysis will be necessary in order to understand the physical properties of these worlds based on globally-averaged measurements. In this task, empirical observation of the Earth (as the only inhabited planet that we know of) and the rest of the planets of the solar system will be our guide to interpret the observations. In this discussion we can review what information these observations of the Earth, seen as a planet would reveal to a distant observer.

A significant fraction of nearby stars are surrounded by disks of dust thought to be replenished by collisions of larger bodies analogous to the Kuiper Belt Objects of our Solar System. I will discuss the basics of debris disks and describe a few prominent examples (Vega, beta Pictoris, HR 8799), the emerging "birth ring" model, the value of panchromatic imaging dusty debris from optical to millimeter wavelengths, and how imaging debris disk structure can constrain properties of planets. I will touch on how ALMA should dramatically improve our understanding.

Classical novae (CN) are eruptive variables resulting from thermonuclear runaway (TNR) on the surface of a white dwarf (WD). The fuel for the TNR is the result of mass transfer in an interacting binary pair. The nova event ejects material from the system at velocities in the range of 200-1200 km/sec leading to the formation of a nebular shell. The study of CN nebular remnants contributes to the understanding of the physical processes in CN , the properties of the underlying WD, the nebular shaping mechanisms, and CN as contributors to the inter-stellar medium. Furthermore, expansion parallax of the shell is an effective method for determining accurate distances to these objects, an important fundamental property. The advent of the HST and large ground based telescopes equipped with adaptive optics has significantly improved the capability of studying the nebular phase of CN. An integral field spectrometer (IFS) coupled with AO is the ideal instrument for observing the nova's strong emission features. I will discuss recent observations of V723 Cas, (Nova Cassiopeia 1995) using the Keck IFS, OSIRIS, the morphology of its nova shell, the method of determining its distance from earth and some analysis techniques used with the IFS 3D data.