Clumpy galaxies are prominent in the early Universe. We present morphological and photometric properties of a wide range of galaxy types and their star-forming clumps in the Hubble Ultra Deep Field. Sizes, scale lengths, and scale heights suggest that galaxies grow by a factor of 2 from z = 4 to the present, and that thick disks are present in the early Universe. The largest clumps of star formation are 107–109M⊙ in different galaxies, much more massive than large star-forming complexes in local galaxies. Dissolved clumps may account for both the exponential disks and the early thick disks of spirals and proto-spiral galaxies.

We discuss the selection of star-forming galaxies at z≃6 through the Lyman-break technique. Spitzer imaging implies many of these contain older stellar populations (>200Myr) which produce detectable Balmer breaks. The ages and stellar masses (∼1010M⊙) imply that the star formation rate density at earlier epochs may have been significantly higher than at z≃6, and might have played a key role in re-ionizing the universe.

The molecular cloud associated with the Sh 254-258 group of 5 small H II regions appears to be forming a (late)-OB association. We have mapped the associated molecular cloud in the J=2-1 line of the CO molecule over 0.75o × 1o, and the CO J=3-2 line toward the 2 main peaks, with the University of Arizona Heinrich Hertz Submm Telescope (HHT). We propose a scenario for sequential formation of the stars exciting the H II regions, triggered by the compression/heating of the molecular gas.

The SuperMACHO project has discovered light echoes from 3 ancient SNe in the LMC. These SNRs are three of the six youngest in the LMC, and are classified as likely SN Ia based on X-ray data.

We present the first results of a targeted survey carried out with the 305m Arecibo radiotelescope to detect HI-line emission from disk galaxies at redshift z > 0.16. We are using this sample to study the evolution of the zero point of the Tully-Fisher relation (TFR) for galaxies at intermediate redshifts. Compared to optical widths, HI measurements sample a larger fraction of the disks, where the rotation curves are typically flat, and are not affected by slit smearing and misalignment or by aperture effects. Thus, in contrast to studies based on optical spectroscopy, this dataset allows for a direct comparison with the local TFR that is technique independent.

We discuss an accurate harmonic development of Lunar ephemeris LE-405/406

The improvement of the dynamical models of solar system bodies’ motions will be very useful for the future space astrometry mission Gaia for a fast identification of objects, to discriminate between the well-known objects and the new ones. ‘Observations in the Past’ with plate archives allow realising it.

We report on new results of our multiplicity study and present our follow-up observations of the recently detected faint companion HD 3651 B, the first directly–imaged T dwarf companion of an exoplanet host star.

The Virtual Observatory effort has undergone a substantial evolution over the last four years. In the talk we will discuss the directions of the current effort, and consider the direction along which the Virtual Observatory might evolve along with various other large astronomy projects. We will also discuss similar efforts in other disciplines and the relation of the VO to Grid Computing.

Astronomical education is entering a new stage of development which is closely connected with the development of new technologies for communication, computing and data visualization. We discuss this evolution in the context of astronomy education in Armenia. As students spend only a short time in Byurakan Observatory for training in observations, they are not able to carry out systematic astronomical observations. Hence their training places emphasis on the use of astronomical archives and analysis of observational data obtained previously with the Byurakan telescopes and other ground-based and space telescopes. Thus, one of the aims of the Armenian Virtual Observatory is to support the training of students in this modern context.

The observational data of the Orion Nebula Cluster (ONC) is reanalyzed by means of new sets of pre-main sequence (PMS) evolutionary tracks including rotation, non-gray boundary conditions (BC's) and either low (LCE) or high convection efficiency (HCE), aiming better understanding of the appropriate physical constraints for the rotational evolution of the stars within the ONC. The role played by convection is a key aspect of our analysis, since there are conflicting results from theory and observations. We derived stellar masses and ages for the ONC by using both LCE and HCE and considered was the role of non-gray atmospheres. Our results show that the resulting mass distribution for the bulk of the ONC population is in the range 0.2-0.4M⊙ for our non-gray models, and in the range 0.1-0.3M⊙ for gray models. In agreement with previous works, we found that a large percentage (∼70%) of low-mass stars (M≤Mtr, where Mtr is a transition mass) in the ONC appears to be fast rotators (P<4days). Mtr depends on the model choosen, being Mtr=0.5 for LCE, Mtr=0.35 for HCE and, as found in previous works, Mtr=0.25 for gray models. Finally, our analysis indicates that a second parameter is needed for a proper description of convection in the PMS phase.

We discuss the evolution of ultra-massive stars.

Radial velocity studies of X-ray binaries provide the most solid evidence for the existence of stellar-mass black holes. We currently have 20 confirmed cases, with dynamical masses in excess of 3 M⊙. Accurate masses have been obtained for a subset of systems which gives us a hint at the mass spectrum of the black hole population. This review summarizes the history of black hole discoveries and presents the latest results in the field.

I review the current status of our observational knowledge of prominent classes of particle accelerators in the Galaxy, namely shell-type supernova remnants (SNRs) and pulsar wind nebulae. I highlight in particular the contribution of the recent improvement in sensitivity of very-high-energy (VHE) γ-ray observations, which are currently the most direct probe of particle acceleration in the Galaxy up to energies of several hundreds of TeV.

Shell-type SNRs have long been proposed as sources of the Galactic cosmic rays. In recent years, X-ray observations have revealed very thin, non-thermal rims in many young SNRs, and I discuss the implications of these observations for magnetic field amplification and the maximum particle energy attainable by acceleration at the blast wave. I then review the current status of the evidence for accelerated nuclei in these objects, and summarise current uncertainties.

The most numerous class of identified Galactic VHE gamma-ray sources is currently that of pulsar wind nebulae (PWNe). The emission from these objects is generally assumed to be predominantly leptonic, and I outline the new information provided by VHE gamma-ray observations beyond what could be inferred from observations of synchrotron emission.

We present the latest results from our study of PNe and HII regions in two Local Group dwarf irregular galaxies IC 10 and NGC 6822.

We discuss the dynamical model of the planet motions and EPM ephemerides.

We have compiled a large number of optical spectra of cool stars taken with different high-resolution echelle spectrographs (R ≃ 40 000). Many of those are available as spectral libraries (Montes et al. 1997, 1998, 1999, <http://www.ucm.es/info/Astrof/invest/actividad/spectra.html)>.

We investigate the properties of Lyman Break Galaxies at z ~ 3 in the Spitzer First Look Survey field. The effective area coverage of the study is ~2.63 deg2, the largest among similar studies of R ~ 24 mag u-dropouts. Photometric redshifts, ages, dust extinctions and stellar masses of the LBGs have been derived through SED fitting. More than 70% of IRAC-detected LBGs have stellar masses of order of ~1011 M⊙, comparable with L* galaxies. The MIR luminosity, which represents the rest-frame NIR, is found to be a good tracer of the stellar mass. As the red (optical−MIR) colors of the massive LBGs suggest, IRAC LBGs are older (〈t〉 ~ 0.9 Gyr) and dustier (〈E(B − V)〉 ~ 0.33) than typical LBGs. The age and the amount of dust indicate that the IRAC LBGs are intermediate population between blue LBG population and red DRG population. The number density of LBGs more massive than 1011 M⊙ is Φ = (1.05 ± 0.15) × 10−5 Mpc−3. This value exceeds the predictions of hierarchicl galaxy formation models.

Formation of GMCs is one of the most crucial issues in galaxy evolution. I will compare CO and HI in the LMC in 3 dimensional space for the first time aiming at revealing the physical connection between GMCs and associated HI gas at a ~40 pc scale. The present major findings are 1) [total CO intensity] ∝ [total HI intensity]0.8 for the 110 GMCs, and 2) the HI intensity tends to increase with the evolution of GMCs. I argue that these findings are consistent with the growth of GMCs via HI accretion over a time scale of a few × 10 Myrs. I will also discuss the role of the background stellar gravity and the dynamical compression by supershells in formation of GMCs.

We present a Véron & Véron based optical extragalactic reference frame progress report.