Abnormal line profiles and line intensities observed in Ap stars, and their deviations from thoseexpected in homogeneous atmosphere provide a strong evidence for an existance of abundancestratification. For a sample of Ap stars in the effective temperature range 7000–9500 K abundancedistributions of Mg, Si, Ca, Cr, Fe are derived from line profiles, and they are compared with thediffusion calculations. A special attention is paid to Ca distribution for which we found an evidence forthe differential stratification of Ca isotopes. Temperature and magnetic field effects on theobserved abundance distributions are discussed.

The Atacama Large Millimeter Array, hereafter ALMA, is a large international telescope project which will be built over the next decade in northern Chile on a site at 5 km elevation. The site provides excellent atmospheric transmission in the millimeter and sub-millimeter wavelength ranges. The project consists of sixty-four 12-m antennas which can be placed on 250 different stations. These stations cover baselines up to 14 km. At the shortest planned wavelength, λ = 0.3 mm, and longest baseline, the angular resolution will be 0.005 arcsec. The receivers are superconducting (SIS) mixers, to provide the lowest possible receiver noise contribution. In the basic ALMA project the 4 highest priority receiver bands will be installed first (see Table 2). These will all have SIS mixers for both polarizations, each with a bandwidth of 8 GHz. A unique feature of ALMA is that this instrument will record both interferometric and total power data. Thus the complete flux density will be recovered. In the following, we present the status of the ALMA project as of end 2003 with a few comments about future developments in the project in Section 7.

The Photodetector Array Camera and Spectrometer on Herschel provides imaging line spectroscopy and imaging photometry in the 55–210 μm wavelength band. In photometry mode, two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, are used to simultaneously image two bands, 60–85 μm or 85–130 μm and 130–210 μm, over a field of view of ~1.75'×3.5', with Nyquist beam sampling in each band. In spectroscopy mode, two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, are used to image a field of ~50''×50'', resolved into 5×5 pixels, with a spectral resolution of ~175 km s-1 and an instantaneous spectral coverage of ~1500 km s-1. In both modes the performance is expected to be not far from background-noise limited, with sensitivities (5σ in 1 h) of ~4 mJy or 3–20×10-18 W/m2, respectively. We summarise the design of the instrument and its subunits, describe the observing modes in combination with the telescope pointing modes, report results from instrument level performance tests of the Flight Model, and present our current prediction of the in-orbit performance of the instrument.

We present detailed star formation and chemical enrichment histories obtained for six isolated Local Group galaxies in the context of the LCID (Local Cosmology from Isolated Dwarfs) project. One of the main goals of the LCID project was to investigate the influence of global processes (like cosmic reionization) or internal mechanisms (such as SNe feedback) on the evolution of dwarf galaxies. We show that all the galaxies in the sample, including those that ended star formation very early on, formed most of their stars after reionization was complete. This demonstrates that reionization alone was not able to stop star formation in these galaxies, as had been expected.

3-D simulations suggest that the atmospheres of red supergiants are subject to large-amplitude convective motions, which are suspected to generate supersonic motions and shocks. We perform tomography of supergiant-star atmospheres, on temporal series of high-resolution spectra and on 3-D hydrodynamical synthetic spectra. The tomographic technique is improved by the computation of the contribution function, which is used to construct numerical spectral masks probing different optical depths. This exploratory work allows us to put spatial and temporal constraints on velocity fields predicted by 3-D model atmospheres.

The Permanent All Sky Survey (PASS) is a project for a continuous photometric survey of the entire celestial sphere with a high temporal resolution. Its major objectives are the detection of all giant-planet transits (with periods up to some weeks) across stars up to mag 10.5, and the delivery of continuous time series photometry that is useful for the study of any variable stars. For a southern instrument of PASS, Dome C offers two major advantages over mid-latitude sites: lower noises and greatly improved observational coverage. The simplicity of the instrument should make it fairly easily adaptable to the extreme low temperatures at that site.

We present a new multi–fluid, grid MHD code PIERNIK, which is based on the Relaxing TVD scheme (Jin & Xin 1995). The original scheme (see Trac & Pen 2003; Pen et al 2003) has been extended by an addition of dynamically independent, but interacting fluids: dust and a diffusive cosmic ray gas, described within the fluid approximation, with an option to add other fluids in an easy way. The code has been equipped with shearing–box boundary conditions, and a selfgravity module, Ohmic resistivity module, as well as other facilities which are useful in astrophysical fluid–dynamical simulations. The code is parallelized by means of the MPI library. In this paper we present Ohmic resistivity extension of the original Relaxing TVD MHD scheme, and show examples of magnetic reconnection in cases of uniform and current–dependent resistivity prescriptions.

Polar ring galaxies are systems with nearly orthogonally rotated components. We have found the gas on polar (or strongly inclined) orbits in two BCD galaxies using ionized gas velocity fields taken with a Fabry-Perot interferometer of the SAO RAS 6-m telescope. Our analysis shows that all ionized gas in Mrk 33 is concentrated in a compact disk (3 kpc in diameter) which rotates in the polar plane relative to the main stellar body. The gaseous disk in Mrk 370 has a more complex structure with a heavily warped innermost part. The presence of polar gaseous structures supports an idea that current the burst of star formation in these galaxies is due to the external gas accretion or merging. A possible fraction of polar structures among BCD galaxies seems to be very large (up to 10–15%).

Using high resolution DM simulations we study the shape of dark matter halos. Halos become more spherical with decreasing mass. This trend is even more pronounced for the inner part of the halo. Angular momentum and shape are correlated. The angular momenta of neighboring halos are correlated.

In this chapter, we examine the question of how spectropolarimetric observations of magnetic stars may be modelled, and how modelling techniques may be used to extract much detailed information about the stellar magnetic field and other characteristics of the magnetized stellar atmosphere.

Modeling tools for eclipsing binary stars are lagging behind the modern observations that are unprecedented both in quality and in quantity. We assembled a team of modeling and interpretation experts and propose to enhance the modeling code to tackle this new-age data. In this paper we outline some of the most important advancements planned and being implemented into the new version of the phoebe code. These advancements will greatly reduce systematics and allow us to focus on prime astrophysics to be gleaned in studying eclipsing binaries and exoplanet transits. For the first time the errors on the masses and radii will be pushed well below 1%.

Throughout the last decades, development of low-temperat- ure detectors focused mainly on the design of high-sensitivity, single-pixel devices. This includes such devices as semiconductor-based photodetectors and bolometers, Magnetic Metallic Calorimeters (MMC), Superconducting Tunnel Junctions (STJ), and Transition Edge Sensors (TES). However, these devices have had limited success in achieving the simultaneous large-scale array sizes and large-bandwidth operation necessary for high-speed, high-resolution detection. To overcome this performance limitation, it is advisable to focus on low-temperature detectors which are intrinsically adapted to giant-array multiplexing and ultra-fast readout. To adopt large scale frequency-domain multiplexing for low-temperature detectors, it is necessary to find detectors which“broadcast” at microwave frequencies. Superconducting microwave resonators naturally lend themselves to this task. One recent demonstration is an implementation known as Kinetic Inductance Detectors (KIDs). This detection mechanism can be adopted for low-energy EM radiation (radio, mm, THz) in continuous mode, or in pulsed mode for higher energy radiation and particles. We present an ongoing development for a KIDs instrument dedicated to millimetric ground-based observations at the 30m IRAM telescope at Pico Veleta. The Neel IRAM KIDs Array (NIKA) project is coordinated in Grenoble and involves groups in Holland (SRON), UK (Cardiff) and Italy (Roma).

A large majority of GRBs exhibit X-ray emission. In addition, a dedicated separate groupof GRB, the XRFs, exists which emission dominates in the X-ray spectral range. And thethird group of GRB related objects (yet hypothetical) are the group of off-axis observedGRBs (orphan afterglows). These facts justify the consideration of an independentexperiment for monitoring, detection and analyses of GRBs and others fast X-ray transientsin X-rays. We will present and discuss such experiment based on wide-field X-raytelescopes of Lobster Eye type. We show that the wide field and fine sensitivity ofLobster Eye X-ray All-Sky Monitor make such instruments important tools in study ofGRBs.

To take advantage of the exceptional seeing above the boundary layeron Antarctic sites, a high-resolution telescope must be mounted on asupport tower. An open transparent tower of framework minimizes theupward temperature-disturbed airflow. A typical minimum height is30 m. The tower platform has to be extremely stable againstwind-induced rotational motions, which have to be less thanfractions of an arc second, unusually small from a mechanicalengineering viewpoint. In a traditional structure, structuraldeflections result in angular deflections of the telescope platform,which introduce tip and tilt motions in the telescope. However, astructure that is designed to deflect with parallel motion relativeto the horizontal plane will undergo solely translation deflectionsin the telescope platform and thus will not degrade the image. Theuse of a parallel motion structure has been effectively demonstratedin the design of the 15-m tower for the Dutch Open Telescope (DOT)on La Palma. Special framework geometries are developed, which makeit possible to construct high towers in stories having platformswith extreme stability against wind-induced tilt. These geometricsolutions lead to constructions, being no more massive than a normalsteel framework carrying the same load. Consequently, theselightweight towers are well suited to difficult sites as onAntarctica. A geometry with 4 stories has been worked out.

Recent observations of prominences obtained with high spatial and temporal resolution instruments, on board satellites (Hinode, SDO) as well as on the ground (SST) have provided very intriguing movies and open a new area for understanding the nature of prominences. The main topics are still debate: formation, dynamics, and characteristics of the plasma in the core and in the transition zone between the prominence and corona. We will review briefly the recent advances made in these topics, observationally as well as theoretically.

Laboratory experiments demonstrate that current sheets evolving in magnetized plasmas can give rise to both flare-type events and generation of energetic plasma jets.

Micromegas detectors, thanks to their good spatial and temporal discrimination capabilities, are good candidates for rare event search experiments. Recent X-ray background levels achieved by these detectors in the CAST experiment have motivated further studies in the nature of the background levels measured. In particular, different shielding configurations have been tested at the Canfranc Underground Laboratory, using a microbulk type detector which was previously running at the CAST experiment. The first results underground show that this technology, which is made of low radiative materials, is able to reach background levels down to 2 × 10-7 keV-1 s-1 cm-2 with a proper shielding. Moreover, the experimental background measurements are complemented with Geant4 simulations which allow to understand the origin of the background, and to optimize future shielding set-ups.

We show that for ionization-driven chemistry in molecular clouds with very sub-solar (but non-vanishing) metallicities, OH replaces CO as the most abundant molecule containing at least one heavy element. Old Population-II stars, with observed metallicities ≲10-3times solar, may have formed in such OH-dominated star-forming clouds, shortly after the heavy elements were first produced at the epoch of reionization in the early Universe.

Stellar models including atomic diffusion processes (gravitational settling, radiative accelerations, thermal diffusion, in addition to the purely diffusive term) have now been evolved throughout most of stellar evolution. We review some of the major roles of diffusion processes in stellar evolution. The emphasis is on interior properties. Examples include Populations I and II stars. It is emphasized that competing advective processes such as mass loss or meridional circulation modify internal concentrations differently from turbulent diffusion even when they lead to the same surface abundances. Radiative accelerations play a major role in horizontal branch and sdB stars.

We have installed a small telescope to monitor the sky brightness around the sun at the French-Italian station Concordia at Dome C in Antarctica. Previous campaigns have been performed with the same instrument at Haleakala in Hawai and Sunspot in New Mexico. We compare here the results of the first year of the campaign at Dome C (2008) to the purest sky observed at Haleakala. We show that Dome C is an outstanding site for coronal observations. Compared to Haleaka, it appears to be more transparent, and to contain less aerosols. Its water vapour content is also significantly smaller. These results still have to be confirmed by the analysis of the 2009 and 2010 data.