We present the first results derived from the spectrophotometric properties of the Vimos VLT Deep Survey (VVDS) first epoch data. We have measured the spectral features (emission/absorption lines, 4000Å break) of a sample a ≈8000 galaxies taken from the VVDS deep 02h and CDFS fields using the platefit VVDS pipeline. We first selected a sub-sample of star-forming galaxies, which were distinguished from narrow-line AGNs by standard and blue diagnostic diagrams. Then the gas-phase oxygen abundances have been derived by fitting all available emission lines towards photo-ionization models. Finally the masses have been derived by fitting all photometric points together with significant spectral features to a library of stellar population models with complex star formation histories. The mass-metallicity relation that we find at low redshifts is in good agreement with previsous studies performed in the local Universe. We find moreover a significant evolution of the mass-metallicity relation with the redshift, the galaxies having on average less metals at a given mass when the redshift increases. We also find a flattening of the mass-metallicity relation up to z ~ 1.

Keeping up with ever more detailed observations, Type Ia supernova (SN Ia) explosion models have seen a brisk development over the past years. The aim is to construct a self-consistent picture of the physical processes in order to gain the predictive power necessary to answer questions arising from the application of SNe Ia as cosmological distance indicators. We review recent developments in modeling these objects focusing on three-dimensional simulations.

The approaches proposed in the past for determining the pattern speeds and corotation radii of the density waves in spiral and barred galaxies are mostly limited in their scope and accuracy. In this work, we have developed a general approach for the determination of corotation radii, which is applicable to any galaxy whose density wave modes have reached quasi-steady state – a condition empirically found to be the case for most nearby disk galaxies. The method utilizes an azimuthal phase shift between the potential and the density distributions for the density wave modes, the existence and the radial variations of which are closely related to the dynamical mechanism leading to the secular evolution of the basic state of the same disk galaxies (Zhang 1996, ApJ, 457, 125). We have used this method to derive corotation radii of over 100 galaxies using the near-infrared images of the Ohio State University Bright Galaxy Survey (OSUBGS, Eskridge et al. 2002, ApJS, 143, 73).

Shear flows are ubiquitous phenomena in astrophysical environments. In the present contribution the stochastic acceleration of energetic charged particles by Fermi-type processes in relativistic shear flows is considered. We briefly summarize recent theoretical progress in the field of viscous shear acceleration and indicate its significance for particle energization in relativistic flows of AGNs and GRBs.

A sample of 35 C–complex objects is present among near–Earth objects. In spite of the poor statistics, some striking differences compared to Main Belt asteroids can be established: for instance the percentage of near–Earth objects (NEOs) showing hydration features is very small. Moreover the spectral slope of C–complex NEOs seems to be anti–correlated with the exposure to the ion flux coming from the Sun, in contrast with the general behavior of C–complex Main Belt asteroids (and of most asteroids, in general). We discuss some possible implications and suggest some preliminary partial explanations.

We propose [Sobouti, arXiv:astro-ph/0603302] an f(R) modification of GR, which admits of a modified Schwarzschild metric. In the weak field limit this amounts to adding a small logarithmic correction to the newtonian potential. A test star moving in such a spacetime acquires a constant speed at large distances. From observations of the velocity curves of spirals, this speed turns out to be proportional to the fourth root of the mass of the central body, in compliance with the Tully-Fisher relation. A variance of MOND emerges as a consequence of the formalism.

Astronomy development in Thailand has improved significantly during the last few years. The government has approved the establishment of the National Astronomical Research Institute of Thailand (NARIT). Roles of NARIT in the development astronomical research and astronomy education in Thailand includes a national framework, national facilities, collaborative research networks, teacher training and public outreach programmes. The new 2.4-metre reflecting telescope will serve not only astronomy community in Thailand but also in Southeast Asia.

We simulate the accretion disk evaporation to study the changes of accretion disk structure during the state transition from the soft state to the hard state. We performed 2 dimensional MHD simulations by including the heat conduction process. We assume the axisymmetric accretion and put a cold rotating gas torus in a hot halo in hydrostatic equilibrium initially. Weak magnetic fields are threaded vertically. Heat conduction equation and MHD equations are solved separately according to the time splitting method. We obtained the result that accretion disk is heated by the hot corona and the hot gas evaporates from the accretion disk surface. We found that magnetic fields lines bended by disk rotation restrict the energy transport vertically and make disk evaporation ineffective.

In this work we have studied CM Draconis, one of the least massive eclipsing binaries known. Its components are very similar, with masses and radii of about 0.23 M⊙ and 0.25 R⊙. We have analysed light curves in the R and I bands to calculate the fundamental properties of this system with accuracies better than 1%. With these results we plan to carry out a thorough test of the models, which have been found to predict smaller radii and larger effective temperatures than observed for these low-mass stars. This will also be especially interesting in the case of CM Dra since the mechanism driving magnetic activity is thought to be different from that of more massive stars. In addition, the extended time-span of the observations has led to the detection of apsidal motion. This provides a further check on models through the determination of the internal structure of the stars.

Superclusters of galaxies are the largest gravitationally bound structures of the Universe. Numerical simulations indicate that a significant fraction of baryonic matter could be located in supercluster (SC) scales in the form of a warm/hot plasma. The sensitivity and resolution of the VSA interferometer at Teide observatory allow us to search for evidence of the Sunyaev-Zeldovich effect (SZE). We have published evidence for such a plasma towards the center of the Corona Borealis Supercluster (CrB-SC), Génova-Santos et al. (2005). Two large decrements in the intensity of the signal measured by VSA at 33 GHz (CrB-B and H) subtending an angle of about 25' could be indicative of a concentration of baryonic matter comparable to thousands of galaxies. This matter could be in the form of a plasma of temperature ~105 − 107 K where no clusters of galaxies have been identified. No other similar spots have been found in the VSA fields observed to measure the CMB primordial power spectrum of fluctuations, Rubiño-Martin et al. (2003), and suggests that this is indeed a very particular feature of the CrB-SC of galaxies. Additional data obtained with the MITO telescope of CrB-H also support this VSA finding Battistelli et al. (2006), and could be related to warm/hot plasma in the SC. We would expect a galaxy population to be associated with such a plasma, as it is well known to occur in clusters of galaxies where the SZE has been measured, Lancaster et al. (2005). However, the absence of X-ray emission in the ROSAT images in the CrB-SC SZ spots suggests that if there is a galaxy population linked to the plasma it may have a peculiar spatial distribution. We obtained photometry of CrB-SC region using the data base from SDSS DR4, covering a total of 15o2 in the CrB-SC area. We built a catogue with 121251 galaxies down a selection criterion based on galaxies colours 0.2 ≤ r − i ≤ 0.6 and δ(g, r, i) ≤ |0.2| errors. In order to study the behaviour of differents regions in the CrB-SC, four regions were measured that belongs it, two regions not associated with overdensity, A2065, and CrB-H with 30' radius for each ones. The completeness magnitude is R ≤ 21. A photometric study produced colour-magnitude diagrams where we can detect evidence that many of these galaxies belong to the same system. The excess in the number density of galaxies appears to be larger in CrB-H where the strongest CMB temperature decrement was found. The number of galaxies in it is a factor ~1.5 lower than A2065 and ~2.5 highest that the SC background field. This resembles the typical number of galaxies in clusters of galaxies. However, it appears these galaxies are more broadly distributed than in the well known clusters of this SC. It is possible that the hot plasma causing the SZ spot is indeed associated with a new large concentration of galaxies unidentified in the SC.

We briefly discuss different methods used to identify HI shells in TB datacubes. Then we give results for our automatic method applied to LDS and LAB HI surveys of the Milky Way (2nd and 3rd quadrants). We fit the radial distribution of HI shells (the exponential profile with the scale length of 3 kpc) and the size distribution (the power law with the index of 2.1). We compare the distribution of identified HI shells with HII regions and study the differences between identifications in the 2nd and 3rd quadrants.

Astrophysical Integrated Research Environment (AIRE), aims to integrate astrophysical data, analysis software and astrophysical knowledge into an easy-to-use Internet based environment. Therefore, astrophysicists from different institutes can constitute virtual research groups which are favorable to study some complex multi-band astrophysical phenomena. The AIRE was put into use in Center for Astrophysics, Tsinghua university in 2003. Up to now, there are 219 advanced users in this environment. Several astrophysical researches base on AIRE have generated some important published results.

The detectability of Seyfert 2 galaxies (Sy2s) with hidden broad-line regions(HBLRs) is still a question open to debate. Using a large sample of 90 Seyfert 2 galaxies (Sy2s) with spectropolarimetric observations (Gu & Huang 2002), we tested the suggestion that the presence of hidden broad-line regions (HBLRs) in Sy2s is dependent upon the Eddington ratio (Nicastro et al. 2003). The stellar velocity dispersion and the extinction-corrected [O III] luminosity are used to derive the masses of central super-massive black holes and the Eddington ratios. The main conclusion are summarized as follows.

SNe Ia are currently providing the most direct measurements of the accelerated expansion of the Universe and also put constraints on the nature and evolution of the so-called ‘dark energy’. Despite major efforts to increase the number of known high-redshift SNe Ia with reliable distance estimates, two regions in the Hubble diagram remain only sparsely observed. At redshifts z > 1 the limitations of ground-based instruments require the Hubble Space Telescope and its superior angular resolution to get meaningful distance estimates, while at intermediate redshifts (z ≃ 0.2) the large solid angle necessary presents an obstacle to most surveys that can be overcome with the Sloan Digital Sky Survey, SDSS-II.

This summary of JD13, Exploiting large surveys for Galactic astronomy, is based on the talks that were given during the meeting and/or submitted to the full proceedings which appeared in MemSAI 77 no. 4, 2006. The electronic version of this MemSAI volume also has the abstracts and images of the posters that were displayed and discussed during JD13. Here can only be listed their titles and authors. A panel discussion followed the talks, and a summary of the topics covered is added. Finally, there come the concluding remarks.

A Virtual Observatory (VO) seeks to provide access to very large volumes of astronomical data over the internet to every interested user, along with software for the data anlysis, and tools for data visualisation, statistics and any other applications which are necessary for mining science from the data. Handling large volumes of data requires extensive computer resources, which may not be available to the end user; transferring data from the data centre to the user needs high bandwidth, which also may not be available. A VO therefore seeks to provide computing resources as well, which could be spread over a grid. The user can locate data of interest through registries, then access the data and analyse it using the computing resources, all through simple user interfaces.

Microquasars provide new insights into: 1) the physics of relativistic jets from black holes, 2) the connection between accretion and ejection, and 3) the physical mechanisms in the formation of stellar-mass black holes. Furthermore, the studies of microquasars in our Galaxy can provide in the future new insights on: 1) a large fraction of the ultraluminous X-ray sources in nearby galaxies, 2) gamma-ray bursts (GRBs) of long duration in distant galaxies, and 3) the physics in the jets of blazars. If jets in GRBs, microquasars and Active Galactic Nuclei (AGN) are due to a unique universal magnetohydrodynamic mechanism, synergy of the research on these three different classes of cosmic objects will lead to further progress in black hole physics and astrophysics.

The problem of light pollution became important mainly since 1960, by growth of urban development and using more artificial lights and lamps at the nighttimes. Optical telescopes share the same range of wavelengths as are used to provide illumination of roadways, buildings and automobiles. The light glow that emanates from man made pollution will scatter off the atmosphere and affects the images taken by the observatory instruments. A method of estimating the night sky brightness produced by a city of known population and distance is useful in site testing of the new observatories, as well as in studying the likely future deterioration of existing sites. Now with planning the Iranian National Observatory that will house a 2-metre telescope and on the way of the site selection project, studying the light pollution is propounded in Iran. Thus, we need a site with the least light pollution, beside other parameters, i.e. seeing, meteorological, geophysical and local parameters. The seeing parameter is being measured in our four preliminary selected sites at Qom, Kashan, Kerman and Birjand since two years ago using an out of focus Differential Image Motion Monitor. These sites are selected among 33 candidate sites by studying the meteorological data obtained from the local synoptic stations and the Meteosat. We measured and used the Walker's law to estimate the Sky brightness for three of these sites

The data obtained using an 8-inch Meade telescope with a ST7 CCD camera for above sites are consistent with the estimated values of the light pollution mentioned above.

Using the multi-wavelength COSMOS survey (Scoville et al. 2006), we develop a method based on purely photometric data to separate the faint VLA-COSMOS radio population into star-forming (SF) galaxies and active-galactic nuclei (AGN). Based on this classification method we select SF galaxies within our sample and present first results on the cosmic (dust-obscured) star-formation history based on VLA-COSMOS (Schinnerer et al. 2006) radio data.

We review some advances relating to direct N-body codes. In particular, there has been significant progress in dealing with large-N systems containing a few dominant members. The simulation of massive black holes also requires treatment of relativistic effects for strongly bound two-body orbits. Although somewhat costly, the addition of post-Newtonian terms is still straightforward when used in connection with regularization methods. Several versions of multiple regularization are especially well suited to studying black hole problems. We also report on a new stability criterion for the general three-body problem which will provide a robust test in systems where hierarchies are a troublesome feature, as in the case of star cluster simulations with primordial binaries.