Within the Cold Dark Matter scenario the hierarchical merging paradigm is the natural result to form massive galactic halos by the minor mergers of sub-halos and, by this, inherently their stellar halo. Although this must be also invoked for the Milky Way, the context of chemical and kinematic coherence of halo stars and dwarf spheroidal galaxies is yet unsolved a focus of present-day research. To examine this issue we model the chemo-dynamical evolution of the system of satellites selected from the cosmological Via Lactea II simulations to be similar for the Milky Way environment but at an early epoch.

In recent years, astronomical photometry has been revolutionised by space missions such as MOST, CoRoT and Kepler. However, despite this progress, high-quality spectroscopy is still required as well. Unfortunately, high-resolution spectra can only be obtained using ground-based telescopes, and since many interesting targets are rather faint, the spectra often have a relatively low S/N. Consequently, we have developed an algorithm based on the least-squares deconvolution profile, which allows to reconstruct an observed spectrum, but with a higher S/N. We have successfully tested the method using both synthetic and observed data, and in combination with several common spectroscopic applications, such as e.g. the determination of atmospheric parameter values, and frequency analysis and mode identification of stellar pulsations.

Two competing theories posit that Ultra Compact Dwarfs (UCDs) form either as the stripped nuclei of dwarf galaxies or as giant globular clusters (GGCs) associated with the largest globular cluster (GC) systems. By focussing on the field and group environments where young UCDs may be most common, we have discovered the first UCD that is clearly the result of recent (< 4Gyr ago) stripping of a companion galaxy during a minor galaxy merger. However, we have also found a definitive case of a multiple-UCD system created via GC formation processes, which are likely associated with major galaxy mergers.

The internal antarctic plateau revealed in the last years to be a site with interesting potentialities for the astronomical applications due to the extreme dryness and low temperatures, the typical high altitude of the plateau, the weak level of turbulence in the free atmosphere down to a just few tens of meters from the ground and the thin optical turbulence layer developed at the ground. The main goal of a site testing assessment above the internal antarctic plateau is to characterize the site (optical turbulence and classical meteorological parameters) and to quantify which is the gain we might obtain with respect to equivalent astronomical observations done above mid-latitude sites to support plans for future astronomical facilities. Our group has been involved, since a few years, in studies related to the assessment of this site for astronomical applications that include the characterization of the meteorological parameters and optical turbulence provided by general circulation models as well as mesoscale atmospherical models and the quantification of the performances of Adaptive Optics (AO) systems. In this talk I will draw the status of art of this site assessment putting our studies in the context of the wide international site testing activity that has been done in Antarctica. I will focus on the site assessment relevant to astronomical applications to be done in the visible up to the near infrared ranges, i.e. those ranges for which the optical turbulence represents a perturbing element for the quality of the images and the AO techniques an efficient tool to correct these wavefront perturbations.

Submillimeter dust continuum emission traces high molecular column densities and, thus,dense cloud regions in which new stars are forming. Surveys of the Galactic plane in suchemission have the potential of delivering an unbiased view of high-mass star formationthroughout the Milky Way. The location of the APEX telescope on the Chajnantor plateau inChile is ideally suited for mapping the inner Galaxy. ATLASGAL, The APEX Telescope LargeArea Survey of the Galaxy at 870 μm, is a survey of the Galactic planeusing the Large APEX Bolometer Camera (LABOCA), in the Galactic longitude and latituderanges of  ±60 and  ±1.5°, respectively. This survey is providing an unbiased sample ofcold dusty clumps in the Galaxy at submillimeter wavelength and a variety of molecularline follow-up observations have been started to characterize the physical and chemicalconditions in the newly found clumps. Here, first results from this survey and itsfollow-up programs are described.

Dust grains are an important component of star forming regions and are therefore a powerful tracer of the location and mass of prestellar cores. However, the properties of dust grains in such dense regions are poorly constrained, causing difficulties in the modeling of the physical properties of dense cores. One of the fundamental properties of dust grains is their size distribution, which is relatively well-known in the diffuse ISM but not very well constrained in dense regions. Indirect evidence is consistent with the presence of large grains; however, to date, interpreting submm emission measurements or absorption in the near-infrared (NIR)/mid-infrared (MIR) domains is difficult due to the ambiguity between density (and temperature if in emission) variations and grain properties. Recently, we have discovered emission at 3.6 and 4.5 μm towards the densest parts of L183. We have named this effect coreshine, by analogy with the cloudshine, seen at the surface of dark clouds in the near-infrared. This 3.6 and 4.5 μm emission can only be explained by the strong scattering of background interstellar radiation due to micron-size grains and show that the average grain size increase needs to be proportional to the cloud core density gradient to reproduce the observations. We show that the scattering effect is very sensitive to the grain size distribution; therefore these observations will provide a new tool with which to study grain properties. In a subsequent search through about a hundred of dense low mass core regions in the Spitzer Heritage Archive, we find that the effect is present in  ~50% of the sources, including prestellar cores, Class 0 and I sources with or without outflow, showing that the coreshine effect should rapidly become a general observational method to investigate dark cloud and grain properties.

We discuss the selection of blue horizontal branch stars (BHBs) using preliminary Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) color data and outline techniques for structure detection using those data. We first outline the adaptation of an old color selection for for BHBs using Sloan Digital Sky Survey (SDSS) data to the Pan-STARRS filter set. We next outline a rudimentary search algorithm designed to autonomously detect substructure in the Galactic halo. Finally we discuss preliminary results and comment on future refinements to the process.

A review of some of the most important studies of the past several decades pertaining to the study of atomic diffusion in stellar atmospheres is presented. A brief description of various studies of radiative accelerations and diffusion calculations in stellar atmospheres is given. Several physical phenomena such as ambipolar diffusion, light-induced drift and the effect of magnetic fields on diffusion are discussed. Results from recent self-consistent model atmospheres including elemental stratification are also reviewed. Particularities of radiative acceleration calculations in stellar atmospheres as well as difficulties and future challenges related to diffusion calculations in stellar atmospheres are also presented.

The nuclei of active galaxies harbor massive young stars, an accreting central black hole, or both. Results are presented for molecular gas that is exposed to X-rays (1–100 keV, XDRs) and far-ultraviolet radiation (6–13.6 eV, PDRs). Particular attention is paid to species like HCN, HNC and HCO+. Line ratios of HCN/HCO+ and HNC/HCN discriminate between PDRs and XDRs.

Pi of the Sky is a system of wide field-of-view robotic telescopes which search for shorttimescale astrophysical phenomena, especially for prompt optical GRB emission. The systemis designed for autonomous operation, follows the predefined observing strategy and adoptsit to the actual conditions. We describe the current status of telescopes located in Chileand Spain and prospects for future development.

In this talk I have presented the data analysis results of extracting properties of halo WIMPs: the mass and the (ratios between the) spin–independent and spin–dependent couplings/cross sections on nucleons by the amidas website. Although non–standard astronomical setup has been used to generate pseudodata sets for our analyses, it has been found that, without prior information/assumption about the local density and velocity distribution of halo Dark Matter, these WIMP properties have been reconstructed with  ~5% to ≲40% deviations from the input values.

It has already been demonstrated that a mesoscale meteorological model such as Meso-NH (Lafore et al. 1998) is highly reliable in reproducing 3D maps of optical turbulence (Masciadri et al. 1999; Masciadri & Jabouille  2001; Masciadri et al. 2004). Preliminary measurements above the Antarctic Plateau have so far indicated a pretty good value for the seeing: 0.27'' (Lawrence et al. 2004 ), 0.36'' (Agabi et al. 2006) or 0.4'' (Trinquet et al. 2008) at Dome C. However some uncertainties remain. That's why our group is focusing on a detailed study of the atmospheric flow and turbulence in the internal Antarctic Plateau. Our intention is to use the Meso-NH model to do predictions of the atmospheric flow and the corresponding optical turbulence in the internal plateau. The use of this model has another huge advantage: we have access to informations inside an entire 3D volume which is not the case with observations only. Two different configurations have been used: a low horizontal resolution (with a mesh-size of 100 km) and a high horizontal resolution with the grid-nesting interactive technique (with a mesh-size of 1 km in the innermost domain centered above the area of interest). We present here the turbulence distribution reconstructed by Meso-NH for 16 nights monitored in winter time 2005, looking at the the seeing and the surface layer thickness.

We report on spectropolarimetric observations of 7 A-type supergiantstaken with the MuSiCoS echelle spectropolarimeter mounted at the 2 m Bernard Lyot telescope at the Pic du Midi, during June-July 1999 and June-July 2002. We present the values of the derived longitudinal component of the magnetic field. The significance of the results isdiscussed.

We present details of the ISON network for GRB follow-up and complete list of observations in 2010–2012.

GAIA will be of paramount importance to understand the Galacticstructure. Here we focus on the determination of the star formationhistory (SFH) of the Galactic disk and bulge. We discuss whether GAIAwill be able to isolate a sample of stars with the samecharacteristics of Hipparcos data (completeness over a certaincritical magnitude and high precision in the distance) which will castlight on the SFH of the whole disk. We analyze the expected results intwo directions, namely the BW and the Galactic pole. Finally wediscuss the contribution of GAIA to the study of the SFH of the bulge.

The original title of this contribution was "Magnetic Fields in theVicinity of Young Stars". One of the goals was to show the impact ofthe large scale magnetic field on the gravitational collapse leadingto star formation, and also to discuss some of Jean-Louis Leroy'scontributions to the measurement of the polarisation, hence thedirection of the magnetic in the interstellar medium made withSTERENN, the polarimeter he and Jean-François Leborgne built for thePic-du-Midi observatory. Another goal of the talk was to survey thestate of our knowledge of the magnetic field in the immediatecircumstellar environment of young stars. In doing that we discoveredan interesting correlation. Therefore, this paper presents only abrief overview of the original talk presented at theconference. Instead, it emphasizes largely on what we consider to bethe most interesting aspect of what was presented, namely, thealignement of YSO, and in particular T Tauri stars, with the localmagnetic field in Taurus.

We are using a sample of more than 50 standard very late-type stars, taken from Isaac Newton Telescope at R  ~ 9000 in the 8100–9100 Å range, in order to develop criteria for spectral and luminosity classification of very late-type stars in the Gaia region. In this article, we brief in a few pages the main challenges on this issue, as well as the literature about it, and we present some preliminary results.

This paper aims at describing (broad lines) the various instrumental concepts for nulling interferometry and how some observational constraints have driven the evolution from the initial Bracewell configuration to the ESA-Darwin mission configuration. Before this short overview, basic principles of interferometry and of nulling interferometry are recalled. Since a key point in the nulling mode is to insert achromatic phase shifts between interfering waves, a short description of several Achromatic Phase Shifters concepts is given as well as the associated constraints.

To fulfil its numerous science objectives, the Gaia mission needs to account for theimpact of the radiations at CCD level. Through the defects generated in the silicon, theradiations will not only degrade the overall signal-to-noise ratio of the measurements,but also corrupt them with a bias to be corrected on ground. In order to characterize thiseffect, and help deriving a proper calibration strategy, an extensive radiation testcampaign has been carried out in EADS Astrium since 2006, covering the differentinstruments and CCD variants. We present an overview of this radiation test bench, and thedifferent investigations performed so far and associated findings.

The Gaia space satellite will perform absolute astrometry, aiming at the definition of aglobal astrometric reference frame at visual wavelengths. Within this reference system, itwill be very difficult to identify possible errors in the measurements or in the datareduction process that brings about the definition of the final catalogue. The Gaia DataProcessing and Analysis Consortium (DPAC) has established an Astrometric Verification Unit(AVU) to verify crucial steps in the baseline data processing chain and report on anysignificant difference. This process is essential in order to guarantee a high qualitycatalogue to the larger scientific community. We describe here the global spherereconstruction (GSR) component of AVU hosted by the Italian data processing centre atTorino (DPCT).