It is well known that rotating inviscid accretion flows with adequate injection parameters around black holes could form shock waves close to the black holes, after the flow passes through the outer sonic point and can be virtually stopped by the centrifugal force. We numerically examine such shock waves in 2D accretion flows with 10−5 to 106 Eddington critical accretion rates around a supermassive black hole with 106M⊙. As the results, the luminosities show QPO phenomena with modulations of a factor 2–3 and with quasi-periods of a few to several hours.

We present new spectroscopic observations of the system of the two blue compact dwarf (BCD) galaxies SBS 0335-052 W and SBS 0335-052 E with the 3.6m ESO telescope. The oxygen abundance in SBS 0335-052 W was determined to be 12 + log(O/H) = 7.13±0.08, confirming that this galaxy is the most metal-deficient emission-line galaxy known. We find that the oxygen abundance in SBS 0335-052 E varies from region to region in the range from 7.20 to 7.31, suggesting the presence of an abundance gradient over a spatial scale of ~1 kpc. Signatures of early carbon-type Wolf-Rayet stars are detected in cluster #3 of SBS 0335-052 E, corresponding to the emission of 20 to 130 WC4 stars, depending on the adopted luminosity of a single WC4 star in the Civ λ4658 emission line (Papaderos et al. 2006).

We investigate some implications of having two star formation episodes in globular clusters, rather than the traditional single-burst approximation. Evidence for more than one stellar generation is accumulating in observations of abundances of elements lighter than iron in globular cluster stars, and is thought to imply some self-enrichment of the globular cluster gas. In particular, we explore models based on the assumption that the self-enrichment comes from an early generation of asymptotic giant branch (AGB) stars.

The vision of the Virtual Observatory (VO) is to make access to astronomical databases as seamless and transparent as browsing the World Wide Web is today. It will federate the data flows from current and future facilities and large scale surveys, and the computational resources and new tools necessary to fully exploit them. This requires both technological developments and an international commitment to standardisation and working culture. Increasingly, it will alter the way that astronomers do science, and the way that future facilities and projects plan for their data management, and the scientific exploitation of their data. It will make an impact on a wide variety of astronomical topics, but especially those using very large databases, and those needing a multiwavelength approach, or more generally the use of multiple archives.

We have developed a robust and efficient algorithm to identify gravitational lensing arcs and interacting galaxies. The algorithm has been applied to the Red Sequence Survey II (RCS II) data, and we demonstrate a few examples here.

One of the outstanding puzzles about star formation is why it proceeds so slowly. Giant molecular clouds convert only a few percent of their gas into stars per free-fall time, and recent observations show that this low star formation rate is essentially constant over a range of scales from individual cluster-forming molecular clumps in the Milky Way to entire starburst galaxies. This striking result is perhaps the most basic fact that any theory of star formation must explain. I argue that a model in which star formation occurs in virialized structures at a rate regulated by supersonic turbulence can explain this observation. The turbulence in turn is driven by star formation feedback, which injects energy to offset radiation from isothermal shocks and keeps star-forming structures from wandering too far from virial balance. This model is able to reproduce observational results covering a wide range of scales, from the formation times of young clusters to the extragalactic IR-HCN correlation, and makes additional quantitative predictions that will be testable in the next few years.

Programs for modeling binary star observables compute emergent intensity for given composition as it varies with local effective temperature, local gravity, and direction. With arrival of huge data sets from Gaia and other surveys, the benefits of fast, compact, and accurate computation of atmospheric radiation is likely to remain critical for the foreseeable future. Experience has shown that accurate radiative modeling is important for good parameter estimation. Here we augment the radiative treatment by Van Hamme & Wilson (2003) with a procedure by which individuals can generate the needed Legendre coefficients for arbitrary photometric bands. Resulting files can be inserted directly into the Wilson-Devinney (W-D) program without sacrificing portability or program unity, and should easily be adaptable to other binary star programs. We expect the new bandpass options to become part of the public W-D program. Limb-darkening tables will be placed at http://www.fiu.edu/~vanhamme/limdark.htm.

In preparation for the first simulation of a real globular cluster with a few 105 particles and several Gyr of evolution, which will be made possible by the advent of the new GRAPE-8, the MODEST community encharged our working group (WG-9) to provide all of the needed observational constrains. The selected clusters for this experiment were NGC 6121 (M 4) and NGC 6397. We present the status of the project.

We have observed over 100 interacting galaxies (IGs) with Spitzer IRAC as part of a detailed study of the their properties (see also Zezas, et al. in this volume). The majority of sources are nearby. Precise IRAC imaging photometry of these galaxies finds a wide range of colors in these systems, and correlative spectroscopic data suggests the colors are reflected by composition that is in turn reflective of age; orientation also plays a role. We have also observed a distant pair of interacting galaxies at z=3.01, a HyLIG, EGS20 J1418+5236 (Huagg et al. 2006), and find that, like the nearby systems, it has similar processes at work albeit in a hyperactive way.

To overcome limitations of some previous studies of IGs, we observed two complementary nearby samples, one selected on the basis of galaxy separation, and the other selected on a morphological basis. Figure 1 below is a summary IRAC [3.6um]-[4.5um] versus [5.8um]-[8.0um] color-color plot of these IGs. Five generic regions emerge: ellipticals near (0,-0.1), early-stage IGS around (1.5, -0.1), Seyfert 1s around (1.3, 0.5), Seyfert 2s around (1.5, 1.2), and LINERS/HII galaxies centered at 2.2, 0.2). These systems are each characterized by spectral dust features in the IRAC bands that are strong enough to influence and]or mirror the underlying stellar continuum colors. The arrows suggest possible evolutionary development.

We measured the SCUBA fluxes of a sample of Seyfert 1, Seyfert 2, starburst and normal disc galaxies, taken from the Extended 12 Micron Galaxy Sample. From these data, we determine the entire dust content and temperature distribution of galaxies of different classes through a Planckian inversion technique.

The HyperLeda database (!http://leda.univ-lyon1.fr) is a tool to study the physics of galaxies. It is based on compilations of heterogeneous data (from large surveys and literature) which are cross-identified and homogenized to produce a uniform representation of the galaxies. We have added in the database a characterization of the nuclear and starburst activity from the Véron and Véron catalogue.

It is now possible to retrieve an activity type for the HyperLeda galaxies having this attribute, and to select list of objects from constraints on activity type. For example, one may select all Sy2 galaxies within some magnitude limits and/or redshift.

We present results of a numerical model for studying the dynamics of Jupiter's equatorial jet. The computed domain is a piece of spherical shell around the equator. The bulk of the region is convective, with a thin radiative layer at the top. The shell is spinning fast, with a Coriolis number = ΩL/V on the order of 50. A prominent super-rotating equatorial jet is generated, and secondary alternating jets appear in the higher latitudes. The roles of terms in the zonal momentum equation are analyzed. Since both the Reynolds number and the Taylor number are large, the viscous terms are small. The zonal momentum balance is primarily between the Coriolis and the Reynolds stress terms.

The observational record of turbulence within the molecular gas phase of the interstellar medium is summarized. We briefly review the analysis methods used to recover the velocity structure function from spectroscopic imaging and the application of these tools on sets of cloud data. These studies identify a near-invariant velocity structure function that is independent of the local environment and star formation activity. Such universality accounts for the cloud-to-cloud scaling law between the global line-width and size of molecular clouds found by Larson (1981) and constrains the degree to which supersonic turbulence can regulate star formation. In addition, the evidence for large scale driving sources necessary to sustain supersonic flows is summarized.

The development process of astronomy in Cuba is analysed from the point of view of a person actually working in astrophysics. It is concluded that the key word for astronomy development is “engagement” between a mature partner and the new developing group. It can not be forgotten that only astronomers do astronomy and that should be the main goal: to develop people working in astronomy.

The year 2006 marks the 1000th anniversary of the supernova of 1006 C.E., the brightest supernova in all of recorded human history. This is also a time of great excitement in the supernova community: Observations from space observatories including Hubble, Chandra, XMM-Newton, and Spitzer, together with ones from powerful new ground-based telescopes and instruments, are revealing supernova remnants in the Galaxy and beyond in unprecedented detail. Fully three-dimensional computational codes and simulations running on powerful new machines are providing insight into the physics of supernovae freed from the simplifying assumptions that have restricted past understanding. Automated supernova searches are discovering hundreds of new supernovae every year, some at redshifts of 1 or beyond. And supernovae have revolutionized cosmology through the discovery of an accelerating universe, and they hold promise for deepening our understanding of the ‘dark energy’ that drives the acceleration.

Extremely red objects were identified in the early Spitzer Space Telescope observations of the bright-rimmed globule IC 1396A; they were classified as Class I protostars Class II T Tauri stars with disks based on their colors. New spectroscopic observations covering 5.5–38 μ confirm this identification. The Class I sources have extremely red continua, still rising at 38 μm, with a deep silicate absorption at 9–11 μm, weaker silicate absorption around 18 μm, and weak ice features including CO2 at 15.2 μm and H2O at 6 μm. The Class II sources have warm, luminous disks, with a silicate emission feature at 9–11 μm. Optical spectra with the Palomar Hale 200-inch telescope show the Class II sources to be actively accreting, classical T Tauri stars with bright Hα and other emission lines. The Class I sources are located within the molecular globule, while the Class II sources are more widely scattered. This suggests two phases of star formation occurred in the region, the first one leading to the Class II sources including LkHα 349a, c that are located in the center of the globule, and a very recent one (less than 100,000 yr ago) that is occurring within the globule. This second phase was likely triggered by the wind and radiation of the central O star of the IC 1396 H II region, with possible additional contributions from the outflows of LkHα 349a, c and some nearby B stars.

We argue that the outburst of CI Cam (XTE J0421+560), probably containing a black hole, was caused by the thermal instability of the accretion disk. Applying the model of King & Ritter (1998), we obtain a realistic disk mass and radius. The differences from soft X-ray transients belonging to the low-mass X-ray binaries can be explained if the disk in CI Cam heats up an extended envelope and/or a strong jet is formed. We resolve several spectral components in the optical colors in quiescence after the outburst; they vary in a complicated way during a possible 1350 d cycle.

We find indications that the variations of the source of the optical light can be related to those of the X-ray source in quiescence. The accretion disk seems to refill at present. Nowadays, only non-periodic intra-night optical (∼0.02 mag) fluctuations are present. As regards the absence of coherent changes in the optical band, we point out the similarities in the situation of CI Cam and the microquasar LS5039/RX J1826–1450.

Over the last five years, enormous progress in accurate distance measurements for nearby galaxies has been attained. The Hubble Space Telescope allows us to estimate distances of about 7–10% accuracy using red giant branch (RGB) up to 8 Mpc. Now we have very accurate distances for more than 200 galaxies within ~6 Mpc.

The stellar population synthesis method is used to model the stellar contribution for a sample of 209 type II AGNs at 0.3>z>0.83 from the Sloan Digital Sky Survey. The reliable stellar velocity dispersions are obtained for 33 type II AGNs with significant stellar absorption features. We use the formula of Greene & Ho to obtain the corrected stellar velocity dispersions (σ*c). 20 of which can be classified as type II quasars. The SMBHs masses and the Eddington ratios are calculated. We measure the gas velocity dispersion (σg) from NLRs, and find that the relation between σg and σ*c becomes much weaker at higher redshifts than at smaller redshifts. We find that the deviation of σg from σ*c is correlated with the Eddington ratio.

Preliminary results of the study of the X-ray spectral variability of 12 Narrow Line Seyfert 1 (NLS1) galaxies are presented. Rms spectra are calculated and compared for the whole sample to search for possible variations with black hole mass. A larger sample of AGN is under investigation.