In this paper we discuss a few aspects of the data volume to be generated by the ESA space astrometry mission Gaia. This volume is assessed first from the on-board point of view in the form of the instantaneous number of sources in the combined astrometric fields of view as a function of time. Then one focuses on the data flow for the data processing itself measured by the number of objects entering the pipeline every day. Finally the combination of the on-board acquisition scheme with the number of stars per day gives the actual telemetry volume to be transferred to the ground and its variation during the mission.

Large-scale shocks propagate in the interstellar medium of starburst and active galaxies, driven by the same mechanisms that regulate the evolution of the star formation and AGN episodes. The imprints of shocks in the chemical composition of the molecular gas provide useful means to identify those mechanisms and to asses their effects. We review some recent and on-going studies of the molecular gas chemistry in the nearby star-forming galaxies IC 342, NGC 253 and M 82, based on the well known shock tracer silicon monoxide (SiO). When mapped at high–spatial resolution the SiO emission reveals substantial differences among these galaxies. In particular, the location of shocks and their dominant driver are in correspondence with the evolutionary stage of the starburst episode. Complementary observations of other tracers of shock chemistry, like methanol (CH3OH), help us to improve the characterization of the shock mechanisms. We also present the first high-resolution observations of the SiO emission in the Seyfert 2 galaxy NGC 1068.

Over the last few years, evidence that nearby spiral galaxies are surrounded by massive halos of cold gas has been accumulating. This extra-planar cold gas, rotating more slowly than the disk gas, is observed in galaxies with a range of different properties (such as mass and star formation rate, SFR) and it appears analogous to the Intermediate and High Velocity Clouds of the Milky Way. Models for the origin of extra-planar gas have been proposed taking into account the effects of supernova feedback (galactic fountain), cooling flow accretion and hydrostatic equilibrium. Several techniques have been used from analytical treatments and ballistic orbit integration to hydrodynamical simulations. I present a new model where a galactic fountain sweeps up ambient medium as it travels through the halo. This seems to give the best results in reproducing the kinematics of the extra-planar gas and it implies a gas accretion rate of the order of the SFR of the host galaxy.

This paper describes the damage occurring in CCDs exposed to solar radiation and explainsits implications for the Gaia measurements by focusing on the astrometric instrument. Itintroduces the strategy that will be used in the Gaia data processing to mitigate theradiation induced effects, and presents CEMGA (CTI effects Models for Gaia) amulti-purpose platform which hosts different models that simulate radiation effects onCCDs.

An invariant classification scheme of algebraicallygeneral rotating dust with a purely electric Weyl tensor ispresented. It turns out that the vorticity vector of the dustcongruence is necessarily parallel to a Weyl principal vector, whichis moreover geodesic. An explicit metric expression can be obtainedfor the subclass of expanding models with one functionallyindependent zero-order Riemann invariant. The basic equations forthe general case, where there are two such invariants, are givenwithin a weighted 1+1+2 tetrad formalism.

We describe recently proposed algorithms, denoted scaled gradient projection (SGP) methods, which provide efficient and accurate reconstructions of astronomical images. We restrict the presentation to the case of data affected by Poisson noise and of nonnegative solutions; both maximum likelihood and Bayesian approaches are considered. Numerical results are presented for discussing the practical behaviour of the SGP methods.

We report the discovery of a new class of non-radial pulsating stars that are the precursors of low-mass white dwarf stars.

The SIM-Lite mission has finished its technology programme and continues with anengineering risk reduction activity while waiting for the results of the 2010 decadalreview. One of the last remaining activities is work on the SCDU testbed, which isdesigned to calibrate the spectral bias in interferometric astrometry to 0.1 microarcsec.This talk will provide a summary of engineering activities on building flight-likeprototypes of the key interferometer subassemblies, as well as an overview of the types ofproblems one encounters when attempting to do astrometry below 1 microarcsec, as well astheir solution.

Red supergiants with their enormous brightness at J-band are ideal probes of cosmic chemical composition. It is therefore crucial to have realistic models of radiative transfer in their atmospheres, which will permit determination of abundances accurate to 0.15 dex, the precision attainable with future telescope facilities in galaxies as distant as tens of Mpc. Here, we study the effects of non-local thermodynamic equilibrium (NLTE) on the formation of iron, titanium, and silicon lines, which dominate J-band spectra of red supergiants. It is shown that the NLTE radiative transfer models enable accurate derivation of metallicity and effective temperature in the J-band. We also discuss consequences for RSG spectrum synthesis in different spectral windows, including the heavily TiO-blanketed optical region, and atmospheric structure. We then touch upon challenges of NLTE integration with new generation of 3D hydrodynamical RSG models and present the first calculations of NLTE spectra with the mean 3D model of Betelgeuse.

Telescope pupils are usually not well suited for high dynamical range imaging. Central obstruction, telescope spiders, hard edges and sparseness (for interferometers) can make it very challenging to build a coronagraph. Fortunately, it is often possible to remap a telescope pupil to achieve high contrast imaging without loosing light. In the case of a monolithic telescope, pupil remapping can produce an apodized pupil with 2 aspheric mirrors which redistribute the light without introducing phase aberrations. Similarly, an interferometer pupil can be remapped into a tight configuration compatible with coronagraphic techniques.

In this paper we give a survey of the methods we have developed for multiple image deconvolution, with application to the reconstruction of the images of the Large Binocular Telescope (LBT). We first describe the main features of LBT and of the Fizeau interferometer, denoted LINC-NIRVANA, that will be one of the basic instruments of the telescope. It will allow to reach the resolution of a 22.8 m mirror by combining different images taken with different orientations of the baseline. Next we discuss the problem of multiple image deconvolution, that is crucial for obtaining a unique high-resolution image from the multiple images provided by LINC-NIRVANA. We present the state-of-the art of the methods based on the Richardson-Lucy (RL) approach and we discuss topics such as computational efficiency, correction of boundary effects and super-resolution. Then, in the perspective of going beyond RL, we extend to the problem ofmultiple image deconvolution the split gradient method (SGM) that isa general approach to the design of iterative methods for the constrained minimization of regularized functionals. Finally we present an application of SGM to the regularized reconstruction of objects with high-dynamic range. The different methods are illustrated with examples taken from the many numerical experiments we performed on this problem.

We present new results on extraplanar DIG (eDIG), based on high spatial resolution narrowband imaging observations of four late-type, actively star-forming edge-on spirals, obtained with ACS on-board HST. Our Hα observations reveal a multitude of structures on both small and large scales. Whereas all four galaxies have been studied with ground-based telescopes before, here the small scale structure of the extended emission line gas is presented for the very first time at a spatial resolution of 0.05′′, corresponding to 5 pc at the mean distance to our galaxies. The eDIG morphology is very different for all four targets, as a result of their different star formation activity and galaxy mass. There is a very smooth DIG morphology observed in two of the galaxies (NGC 4634 and NGC 5775), whereas the other two (NGC 4700 and NGC 7090) show a much more complex morphology with intricate filaments, and bubbles and supershells. We find that the morphology of the eDIG, in particular the break-up of diffuse emission into filaments in galaxy halos, shows a strong dependence on the level of star formation activity per unit area, and eDIG can be arranged into a morphological sequence.

In a recent study we have used a large sample of extragalactic radio sources to investigate the redshift evolution of the Rotation Measure (RM) of polarized quasars up to z ≈ 3.0. We found that the dispersion in the RM distribution of quasars increases at higher redshifts and hypothesized that MgII intervening systems were responsible for the observed trend. To test this hypothesis, we have recently obtained high-resolution UVES/VLT spectra for 76 quasars in our sample and in the redshift range 0.6 < z < 2.0. We found a clear correlation between the presence of strong MgII systems and large RMs. This implies that normal galaxies at z ≈ 1 already had large-scale magnetic fields comparable to those seen today.

The cataclysmic variables are associated with high energy events and probably many ofthem could be potential gamma-ray sources. Up to now Fermi-LAT detected 3 gamma-raytransients, which belong to CVs and related objects: V407 Cyg, N Sco 2012 and N Mon 2012 =V959 Mon. We present the first multicolour observations of the slow classical nova V959Mon.

The mass distribution of galaxy clusters can be determined from thestudy of the projected phase-space distribution of cluster galaxies.The main advantage of this method as compared to others, is that itallows determination of cluster mass profiles out to very largeradii. Here I review recent analyses and results on this topic. Inparticular, I briefly describe the Jeans and Caustic methods, and theproblems one has to face in applying these methods to galaxysystems. Then, I summarize the most recent and important results onthe mass distributions of galaxy groups, clusters, and superclusters.Additional covered topics are the relative distributions of the darkand baryonic components, and the orbits of galaxies in clusters.

We are planning three space astrometry missions as a series of JASMINE missions; Nano-JASMINE, Small-JASMINE and (Medium-sized)JASMINE. JASMINE is an abbreviation of Japan Astrometry Satellite Mission of INfrared Exploration. The JASMINE mission will measure in an infrared band annual parallaxes, positions on the celestial sphere, and proper motions of many stars in the bulge of the Milky Way (the Galaxy) with high accuracies. A target launch date is the first half of the 2020s. Before the launch of JASMINE, we are planning Nano-JASMINE and Small-JASMINE. Nano-JASMINE uses a very small nano-satellite and it is determined to be launched in 2011. Small-JASMINE is a downsized version of the JASMINE satellite, which observes toward restricted small regions of the Galactic bulge. A target launch date is around 2016. A completely new “map” of the Galactic bulge given by Small-JASMINE and JASMINE will bring us many exciting scientific results.

CASPER (Concordia Atmospheric SPectroscopy of Emitted Radiation)is a spectrometer proposed for installation at Dome C, devoted tomeasurements of atmospheric emission in the spectral regionbetween 180 μm and 3 mm (3–55 cm-1). Thisinstrument will be able to perform continuous spectral sampling atdifferent altitudes at angular scales of ~1°. From therecorded data it is possible to extract atmospheric transmittancewithin 1% in the whole wide operating band, together with watervapour content and O2 and O3 concentrations. CASPER willallow us to characterize the site for future FIR/mm telescopes.Atmospheric data recorded by CASPER will allow for correction ofastrophysical and cosmological observations without the need fortelescope-specific procedures and further loss of observation timewith more precision in the observations themselves. Calibration ofground-based telescopes on known sky sources is strongly affectedby atmospheric absorption. CASPER has this as its primary goal.The spectrometer is based on a Martin-Puplett interferometer. Twodata sampling solutions will be performed: phase modulation &fast scan strategy. Sky radiation is collected towards theinterferometer by an optical setup that allows the field of view,to explore the full 0° ÷ 90° range of elevation angles. Witha low spurious polarization instrument, monitoring of polarizedatmospheric contribution will be possible.

The Finite Rank Approximation (FRA) based methodis well known in operator approximation theory but it is also useful for suggesting numerical methods for solvingintegral equations. In this document we describe two FRA methods for the numerical resolution of the integral formulation of the 1D RadiativeTransfer Equation (RTE) posed in a static slab; we browse some advantages of them (especially the possibility to control the error) and we give some reduction of computation technics (iterative refinement schemes)which can be used with these methods. Numerical results obtained for a realistic Sun atmosphere model are given. In the last section we give an example of an inverse problem associated to the RTE:we show the iterative recovering of the albedo from the measurement of the outgoing specific intensityat a surface of the considered domain.

Due to the typical high atmospheric noise and low transparency, submillimeter observations can be carried out only from sites with very high atmospheric stability and very low precipitable water vapour content. The Antarctic Plateau is important because of its remarkable atmospheric transparency and stability. Logistical difficulties have limited till now the exploitation of the unprecendented potential of Antarctica as a site for submillimeter observations. The opening of Concordia Station at Dome C is now offering to the international astronomical community a unique opportunity to perform ground-breaking astronomical science. The proposal from our multi-national group represents a first step toward the realization of an international Antarctic Submillimeter Observatory (ASO) based on a telescope with a large collecting area (12 m diameter) to carry out both continuum and spectral line observations, particularly in the 200 and 225 μm atmospheric windows and possibly also in the Mid InfraRed at wavelengths ≳40 μm.

Three topics within GAIA photometry have been selected for discussionhere. (1) The sampling scheme of the CCDs has been tuned to serve thevarious purposes: detection of stars, astrometry, broad- andmedium-band photometry, and imaging of a small area around eachdetected star, but the tuning may not yet be optimal. (2) Thecalibration of CCD sensitivity is critical since we aim formillimagnitude accuracy, the spikes of the diffraction image aresuited for an accurate calibration of the magnitude scale, and forextending the range of astrometry and photometry to very bright stars.(3) Finally the various photometric filter systems are illustrated.