The detailed abundance patterns in extremely metal-poor (EMP) stars are examined, using the results of the First Stars ESO-VLT Large Program on large samples of dwarfs (located close to the main sequence turnoff) and giant stars (Cayrel et al. 2004; Bonifacio et al. 2007 and subsequent papers). Abundances measured in giants are compared to those measured in turnoff stars, and to comparable quality data in the literature, to demonstrate that the systematics involved in most abundance ratios are very small. A few exceptions are discussed: a reanalysis of Na and Al in EMP samples is performed using NLTE computations. In addition, giants with luminosities brighter than the RGB bump are shown to exhibit the sign of surface pollution by mixing of the products of H-burning, affecting the measured abundances of C, N and Li. 
The implications of a few key abundance ratios (among those considered to be robust and representative of the early galactic gas) are examined in terms of the early Milky-Way enrichment processes and the possible nucleosynthesis contributors (PISNs, SNII, hypernovae). The very low dispersion found around the mean trends is also discussed in terms of chemical enrichment processes.

We provide insight into the origin of the far-IR to mm emission from the Galaxyby presenting a decomposition of the emission where we separate thecontributions from dust in the atomic gas and dust associated with quiescent molecular gas, as a function ofGalacto-centric distance. We find that the sub-mm dust emissivity per hydrogen change by afactor 3 between the diffuse ISM and molecular clouds, first observedon localized clouds in the Solar Neighborhood, applies on large scaleto the Molecular Ring. The decomposition leaves an emission excess inthe sub-mm with a very cold effective temperature, concentratedin the plane but with a brightness independent of Galacticlongitude. This emission might be associated with interstellar matterin the outer Galaxy not traced by H I nor CO emission.

A possible method of pupil apodization using Zernike's phase contrastis presented. I recall the phase contrast principle and show through numericalsimulations that it may be used to generate an apodization using very simpleoptics in the monochromatic case. I also demonstrate that the generalformalism for Lyot and Roddier & Roddier coronagraphy can be extended to theZernike case. This may improve the quality of the simulations undertakento demonstrate the technique's performances.

In low-mass disks, turbulent torques are probably the most importantway of redistributing angular momentum. Here we present the theory ofturbulent accretion disks. We show the molecular viscosity is far toosmall to account for the evolutionary timescale of disks, and wedescribe how turbulence may result in enhanced transport of (angular)momentum. We then turn to the magnetorotational instability, whichthus far is the only mechanism that has been shown to initiate andsustain turbulence in disks. Finally, we present both the basis andthe structure of α disk models.

We report the results of performance evaluation of the first Japanese astrometry satellite, Nano-JASMINE. It is a very small satellite and weighs only 35 kg. It aims to carry out astrometry measurement of nearby bright stars (z ≤ 7.5 mag) with an accuracy of 3 milli-arcseconds. Nano-JASMINE will be launched by Cyclone-4 rocket in August 2011 from Brazil. The current status is in the process of evaluating the performances. A series of performance tests and numerical analysis were conducted. As a result, the engineering model (EM) of the telescope was measured to be achieving a diffraction-limited performance and confirmed that it has enough performance for scientific astrometry.

A new description of the halo's dynamics is introduced. The response of haloes interacting with the accretion and the tidal field is described analytically in the non-linear and secular regime via a perturbative approach. It relates the dynamical properties of a population of such objects to the statistics of their environment. The latter are deduced from cosmological simulations and first results on the anisotropy of accretion, its kinematic properties and the two-point correlation of the tidal field and the density flux of mass are described. This approach should allow to predict the statistical properties of the dark matter tracers within the galaxy (e.g. Lensing, X Emission) or conversely, use these observational probes to constrain the characteristics of haloes' environments.

In this presentation, we first introduced the definition and classification of rotating sunspots. Using multi-wavelength data, we investigated the evolution of some rotating sunspots and the response of upper atmosphere relevant to the rotating sunspots. Moreover, the distribution of rotating sunspots in solar cycle 23 and the statistics of flares relevant to rotating sunspots are also presented.

We have analyzed the distributions of CO and temperature in a large suite of simulatedmolecular clouds, in order to help us understand how to interpret CO line emission fromreal molecular clouds. We find that most of the CO is located at densities over103cm-3 where the temperature is roughly 10–20 K independently ofthe mean density, metallicity and UV field strength. Although, most of the volume is inwarmer and thinner regions where CO abundance is small. On that account, CO observationsalone give a misleading view of the physical conditions in the clouds.

Chemical abundances and radial velocities for ∼210 stars in WLM, ∼130 new stars from DEIMOS spectroscopy, and 80 stars from Leaman et al. (2009) are presented. This sample shows that this isolated dwarf has chemically, dynamically, and spatially distinct stellar populations similar to the nearby dwarf spheroidals. The kinematics of the stars appear to be decoupled from the HI gas, which shows a higher rotational velocity profile. This thicker stellar configuration for a distant, isolated dwarf irregular may have implications for timescales of tidal transformation scenarios of infalling galaxies in the Local Group.

The Concordia Station (Candidi 2003), on the AntarcticaPlateau, will soon become one of the best observatories to performinfrared observations in the 2–20 μm atmospheric windows andbeyond, thanks to its low sky background, low temperature andhigh atmospheric transparency. The possibility of passivelycooling the telescope is a further advantage. We describe herethe first permanent Antarctic infrared telescope, underdevelopment for the Dome C base. It is the InternationalRobotic Antarctic Infrared Telescope (IRAIT). We briefly outlinea few scientific motivations for it, then we review the technicalcharacteristics and the status of its development. The infraredcamera for IRAIT is described in another dedicated paper in thisvolume.

As the SALT High Resolution Spectrograph is nearing completion, we plan to extend the Pennsylvania-Torun Planets Search (PTPS) with HET to the southern hemisphere. Due to overlap of the skies available for both HET and SALT in the declination range (+10, -10) deg, some cooperation and immediate follow-up is possible. Here we present, as an example, a ~1000 star sample of evolved stars for the future SALT Planet Search.

The ESA Gaia mission uses two telescopes to create the most ambitious survey of the Galaxy. The angle between them must be known with exquisite precision and accuracy. An interferometer: the Basic Angle Monitoring system measures its variations. High quality data have been retrieved and analysed for more than a year. A summary of the in-orbit performance and some early results are presented.

The detection is a real challenge for most of the UV-space missions. First, the classical detectors quantum efficiency is very low between 100 and 300 nm. The second point is that the useful flux is very low, and the photon counting is sometimes required. The stray light flux (visible light) is often strong so that additional filters are needed. In addition to the fact that these filters reduce the effective quantum efficiency, it is well known that the filter quality is a big constraint for the UV applications. For these reasons, dedicated detectors with high performances are required. Fortunately, strong improvement in detectors has been done for years and promising detectors are merging. After having reminded the different UV-space mission needs, this paper will present the available UV detectors. In the last part, the CNES Roadmap will be shortly discussed.

An introduction to R is proposed. This pratical session is an excerpt from practical exercises proposed by A. Dalalyan at EPNC (see http://certis.enpc.fr/∼dalalyan/Download/TP_ENPC_1.pdf). Datas are also extracted from a practical session proposed by hydrologic data from Amazonia proposed by D. Chessel A.B. Dufour in Lyon 1 (website indicated in the text below) and from other practical exercises proposed by A. Dalalyan at ENPC (same address as above but ended by /TP_ENPC_4.pdf).

We present a Monte Carlo (MC) radiative transfer code for complex three dimensional dust distributions and include transiently heated PAH. The correctness of the code is confirmed by comparison with benchmark results. The method makes use of the parallelization capabilities of modern vectorized computing units like graphic cards. The computational speed grows linearly with the number of graphical processing units (GPU). On a conventional desktop PC, our code is up to a factor 100 faster when compared to other MC algorithms. As an example, we compute the dust emission of proto-planetary disks. We simulate how a mid-IR instrument mounted at a future 42 m ELT will detect such disks. Two cases are distinguished: a homogeneous disk and a disk with an outward migrating planet, producing a gap and a spiral density wave. We find that the resulting mid-IR spectra of both disks are almost identical. However, they can be distinguished at those wavelengths by coronographic, dual-band imaging. Finally, the emission of PAHs exposed to different radiation fields is computed. We demonstrate that PAH emission depends not only on the strength but also strongly on the hardness of the radiation, a fact which has often been neglected in previous models. We find that hard photons (>20  eV) easily dissociate all PAHs in the disks of T Tauri stars. To explain the low, but not negligible detection rate (<10%) of PAHs in T Tau disks, we suggest that turbulent motions act as a possible path for PAH survival.

Observations of jet- like phenomena near the solar limb are reported for a long time, first in Hα (Secchi observations of spicules in the 1870 ies), and after, from eclipse high resolution coronal images taken in white-light (1920–1973) as spiky structures. EUV jets were reported in the 70 ies from rocket and space-borne CIV filtergrams and finally X-EUV jets were reported from SXT observations of Yohkoh and from EIT and CDS SoHO observations. There is now little doubt that they are of magnetic origin although no magnetic field measurements exist for these regions and thermo-dynamical models are still work out. New observations of both spicules and jets with the SOT/SXT of Hinode were subjected to an analysis showing the influence of the null point(s) of the magnetic field. The collective behavior of the H CaII SOT(Hinode) time sequences of processed with the Madmax operator images of limb spicules show the torsional effects which were partly suggested before from the interpretation of high resolution limb spectra taken on Russian coronagraphs and the VTT at SacPeak. 100 s and shorter period waves are recorded. We propose a reconnection process occurring at the top of an emerging twisted flux tube for explaining some peculiarities of the spicular eruptions and possibly, as a viable mechanism for explaining the SXR jet eruptions. The result of a numerical 3D modeling illustrates this erupting mechanism although the behavior of the magneto-plasma structure near a null point, as shown by coronal filtergrams, does not necessary imply reconnections, especially the case of jets making a long coronal ray we observed in white-light with Lasco C2.

The difficult goal of directly detecting a planet around a star requiresto cancel as much as possible the stellar light.Since the first proposal by Bracewell of a nulling interferometer, where thestar is put on a central dark fringe, several interferometricconfigurations have been presented in order to improve the quality ofthe rejection, especially to avoid the leaks due to the finite angular dimensionof the stellar disk, resolved by the interferometer. In the Bracewell interferometer, the behaviour of the nulling efficiency vs the angular distance θ to the star is as (1-cosθ)∝ θ2. One goal is to increase the exponent of the term θn whichgives the cancellation efficiency. I present one method to define configurations of telescopes positions, sizes and phase-shift that canachieve any given power of θ. The principle is based on a peculiar property foundby Prouhet of a partition into two sets of the integers, done according to the Thué-Morse sequence.2L telescopes regularly spaced on a line, are distributed into two groups, following their rankin the Thué-Morse sequence and, to the telescopes of one of the groups, is applied a π phase shift. The result is a fractal-like distribution of the telescopes where redundancy is minimum andwhose interferometric combination produces a very efficient nulling in θ2L.I first examine 1-D patterns of identical telescopes, then extend the method to 2-D configurations, then show that the lattercan be used to define 1-D arrays of non identical telescopes, according to some algebra of interferometers. The generalizationto arrays where the phase shift between n groups of telescopes is 2kπ/n is finally proposed.

Recent advances in the determination of stellar abundances and their impact on thestudy of nucleosynthesis and the chemical evolution of galaxies are discussed. It is argued thatdetailed interpretation of the abundance patterns among chemical elements foundat different metallicities still requires solid spectroscopic data. Despite current improvementsin abundance analyses, these are not, however, free from systematic errors which can hidethe real history of the chemical evolution. Some examples are discussed.