Receivers for the millimeter and sub-millimeter range employ SIS mixers for the coherent detection of astronomical signals. A very brief overview of the theory of SIS mixers is given, followed bya presentation of recent mixer development at IRAM.

Galaxy formation and evolution is one of the most challenging tasks in astrophysics. There is strongly increasing and substantial progress in this field not only due to the increase of telescope size and developments of new techniques providing observations allover the electromagnetic spectrum, but also the development of advanced computer architectures and of sophisticated numerical codes allow to tackle this problem from both sides and to link both research approaches to a fruitful progress in astrophysics. This review will not focus on the application of a single numerical method and the description of its result, but is instead aiming at providing an overview of different numerical tools on the basis of particle and grid schemes and to referring to important publications for the intersted reader.

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.

The photometric instruments in space (most, corot)are going to open new insights on the knowledge of stellar interiors. However,ground-based asteroseismic observations remain justified as they can bring complementary velocity measurements, and allow the study of much more targets. A competitive instrument must make it possible the observation of a representative set of solar-like starswith magnitude down to 5, and a velocity precision as low as a few cm s-1 after 5 nights behind a 2-m class telescope. The siamois project based on a Fourier interferometer has emerged as asuitable solution to fulfil the specifications for a ground-basedasteroseismic network. The photon noise limitedperformances have been examined and compared to those of a gratingspectrometer (Mosser et al.  2003) showingthat this type of instrument can reach the required specifications. With a design based on a monolithic interferometer, with a compactinstrument easy to set up, to operate remotely with a limited data-flow, it can fit well the harsh conditions of Dome C. Main advantage, a single unit is needed due to the circumpolar position of the targets for the Doppler detection of stellaroscillations on solar-type stars.As a test bed, siamois could be put on 0.8-m class telescope like irait (Busso et al.   these proceedings).

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.

The ESA space mission Gaia, planned to be launched at the end of 2013, will make astrometric, photometric and spectroscopic measurements of about 1 billion sources in our Galaxy. Amongst these sources will be numerous multiple systems. In the processing chain eclipsing binaries (EBs) will be detected and, if possible, their period and characteristics determined. Here we summarize the various steps that are foreseen to automatically classify and characterise these EBs.

Direct imaging searches have begun to detect planetary and brown dwarf companions and to place constraints on the presence of giant planets at large separations from their host star. This work helps to motivate such planet searches by predicting a population of young giant planets that could be detectable by direct imaging campaigns. Both the classical core accretion and the gravitational instability model for planet formation are hard-pressed to form such planets in situ. Therefore, direct imaging searches have traditionally appealed to the possibility of in situ planet formation via a large scale gravitational instability. Here, we show that dynamical instabilities among planetary systems that originally formed multiple giant planets much closer to the host star could produce a population of giant planets at large separations. The number and distribution of such planets is a strong function of time, complicating the statistical analysis of direct imaging surveys. The number and radial distribution of such planets is related to the number of giant planets formed per host star and the timescale for the disk evolution. Thus, direct imaging programs with sufficient sensitivity and survey size could place interesting constraints on planet formation models.

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.

Both emission and absorption techniques have been developed at the AILES beamline of SOLEIL synchrotron to record far infrared (FIR) spectra of transient species. To illustrate the possibilities offered by our absorption set-up, we report in this paper new rotational transitions of the SO radical falling in the spectral range covered by the HIFI spectrometer onboard Herschel.

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.

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 investigate the influence of radiative transport on the growth of the magnetorotational instability (MRI) in accretion discs. A general dispersion relation describing the growth of small disturbances on a homogeneous background shear flow is provided. It includes compressibility and radiative effects in the flux-limited diffusion approximation. All the effects of radiation transport can be subsumed into one single parameter, an effective speed of sound. Radiative diffusion does not affect the region where the MRI operates, but it alters the growth rates of the MRI either by increasing or decreasing them. We report about corresponding numerical simulations, which are also used for a first investigation of the non-linear stage of the MRI in gas-pressure dominated accretion discs with radiation transport included.

The Origins Billions Star Survey (OBSS) is a space astrometry mission that was funded byNASA in 2004 to perform an eight-month concept study. Although the OBSS mission was notselected for further development beyond the concept study phase, OBSS spawned asmaller-scale mission, called the Joint Milli-Arcsecond Pathfinder Survey (JMAPS), whichis currently funded for launch in early 2014. JMAPS is a small, space-based, all-skyvisible wavelength astrometric and photometric survey mission for 0th through 14th magnitudestars. The primary objective of the JMAPS mission is the generation of an astrometric starcatalogue with better than 1 milliarcsecond positional accuracy and photometry to the 1%accuracy level, or better, at 1st to 12th magnitude.

The formation of resonant planets pairs in exoplanetary systems involves planetary migration inside the protoplanetary disc: an inwards migrating outer planet captures in Mean Motion Resonance an inner planet. During the migration of the resonant pair of planets, the eccentricities are expected to rise excessively, if no damping mechanism is applied on the inner planet. We express the required damping action to match the observations, and we show that the inner disk can play this role. This result applies for instance to the system GJ 876: we reproduce the observed orbital elements through a fully hydrodynamical simulation of the evolution of the resonant planets.

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.

VIHI: the Visible and Infrared Hyperspectral Imager is one of the three channels of the Simbio-Sys instrument for the BepiColombo mission to Mercury. Its scientific objective is to study the hermean surfaces composition by sensing the photon flux reflected off the planet. VIHI works in the range of 400 to 2000 nm with a spectral resolution around a few hundreds. The particularity of this channel is the use of a single detector matrix (264 × 264) for both visible and infrared wavelengths. Getting the visible part of the detector responsivity is achieved by thinning an infrared HgCdTe matrix because visible light is completely absorbed inside the substrate. The thinning process is well controlled since a long time and was used to increase number of thermal cycle of the hybrid devices. Recently, this process is able to remove completely the substrate and, thus, open the detector to the visible range. The detector is a custom design made by Raytheon Vision System in Goleta (USA). In this paper, we will describe the expected performances of the detector which is designed to work in the very harsh radiation environment of Mercury.

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.

The Gaia-ESO Survey (GES) is a large public spectroscopic survey that aims at observing with FLAMES@VLT the main stellar components of our Galaxy. The study of the population of open clusters is one of the main objectives of GES. We present some results from the first 18 months of observations, among them, a preliminary view of the radial metallicity gradient as traced by open cluster data and a comparison of the chemical patterns of clusters located in different parts of the Galactic disk.

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.