Supergranules are observed in the high photosphere as large convection eddies with horizontal diverging flows from the cell centre and subsiding flows at the cell borders.

The critical property of the black hole is the presence of the event horizon. It may be detected only by means of the detailed study of the emission features of its surroundings. The temporal resolution of such observations has to be better than ∼ rg/c, and it lies in the 10−6–10s range depending on the black hole mass. In SAO RAS we have developed the MANIA hardware and software complex based on the panoramic photon counter and use it in observations on 6m telescope for the search and investigation of the optical variability on the time scales of 106–103 s of various astronomical objects. We present the hardware and methods used for these photometrical, spectroscopic and polarimetrical observations, the principles and criteria of the object selection. The list of the latter includes objects with featureless optical spectra (DC white dwarfs, blazars) and long microlensing events.

We present the results of the observations of two objects-candidates – long MACHO event MACHO-1999-BLG-22 and radio-loud x-ray source with featureless optical spectrum J1942+10 – on the 6-m telescope in June-July 2006.

Young massive star-forming regions are known to produce hot molecular gas cores (HMCs) with a rich chemistry. While this chemistry is interesting in itself, it also allows to investigate important physical parameters. I will present recent results obtained with high-angular-resolution interferometers disentangling the small-scale structure and complexity of various molecular gas components. Early attempts to develop a chemical evolutionary sequence are discussed. Furthermore, I will outline the difficulty to isolate the right molecular lines capable to unambiguously trace potential massive accretion disks.

We review the main ideas discussed during the meeting and propose methods for a new generation of space accelerators

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.

Magnetohydrodynamic equilibria for a plasma in a gravitational field are investigated analytically. For equilibria with one ignorable spatial coordinate, the equations reduce to a single nonlinear elliptic partial differential equation for the magnetic potential A, known as the Grad-Shafranov equation. Specifying the arbitrary functions in the latter equation, one gets a nonlinear elliptic partial differential equation (the sinh Poisson equation). Analytical solutions of this equation are obtained for the case of an isothermal atmosphere in a uniform gravitational field. The solutions are obtained by using the tanh method, and are adequate for describing parallel filaments of diffuse, magnetized plasma suspended horizontally in equilibrium in a uniform gravitational field.

We present new BIMA observations of the massive star-forming region IRAS 23033+5951 in Cepheus. 3 mm continuum observations reveal that the source decomposes into at least three dusty clumps, each of which has sufficient mass to form a massive star. The most massive clump has a mass of about 225 M and appears to house the massive protostar which drives the prominent CO outflow seen in the region. Our H13CN, 1-0, N2H+ 1-0, and H13CO+ 1-0 maps show that the three continuum sources are all embedded in an elongated structure whose long axis is perpendicular to the outflow. Both H13CO+ and H13CN peak at the geometric center of this structure, which lies between the two prominent continuum peaks. All three lines – H13CN, H13CO+, and N2H+ –show the same velocity gradient along the long axis of their integrated intensity maps. Although the approximately 90,000 AU length of the elongated structure prohibits a disk interpretation, the fact that the dynamical and gas masses of the structure differ by only a factor of a few suggests that the structure may be partially rotationally supported. We also detect a signature of infall toward the center of the structure, seen as an asymmetrically blue HCO+ line where its optically thin isotope, H13CO+, is symmetric and single-peaked.

I present results from numerical simulations of gas dynamics outside luminous accretion disks in active galactic nuclei. The gas, gravitationally captured by a super massive black hole, can be driven away by the energy and momentum of the radiation emitted during black hole accretion. Assuming axisymmetry, I study how the mass accretion and outflow rates, and the flow dynamics respond to changes in radiation heating relative to radiation pressure.

I find that for a 108 M⊙ black hole with the accretion luminosity of 0.6 of the Eddington luminosity the flow settles into a steady state and has two components: (1) an equatorial inflow and (2) a bipolar inflow/outflow with the outflow leaving the system along the disk rotational axis. The inflow is a realization of a Bondi–like accretion flow. The second component is an example of a non-radial accretion flow which becomes an outflow once it is pushed close to the rotational axis where thermal expansion and radiation pressure accelerate it outward.

The main result of this preliminary work is that although the above two-component solution is robust, its properties are sensitive to the geometry and spectral energy distribution of the radiation field.

The IMF UNIVERSALITY HYPOTHESIS cannot be discarded despite the existence of the CLUSTER IMF THEOREM. This means that the currently existing star-formation theory fails to describe the stellar outcome. The IGIMF THEOREM, however, predicts a variation of galaxy-wide IMFs in dependence of the galaxy's star-formation rate even if the IMF UNIVERSALITY HYPOTHESIS is valid. Taking indirect evidence from chemical evolution studies and the IGIMF THEOREM into account, it follows, however, that bulges and elliptical galaxies may have had a top-heavy IMF. A break-down of the IMF UNIVERSALITY THEOREM would thus be evident in extreme galaxy-wide (≳ 10 M⊙yr) star-formation events.

We investigate the rotation of dark matter halos identified in ΛCDM simulations. After removing halos that contain a significant amount of substructure, about 82% of the remaining halos were found to undergo coherent rotation over 5h−1 Gyr. The rotation speeds follow a log-normal distribution. The average rotation speed of a halo was 0.11h rads/Gyr. Less than half of the selected halos showed alignment between their rotation and minor axes. We found no correlation between halo properties, such as total mass, and the rotation speed.

Processing long-baseline interferometry data presents a unique set of complications: How does one derive relative astrometry from interferometric data? How can 1-D interferometric results be used to solve a 2-D orbit? How can baseline-only solutions be combined with historical data and how should interferometric data be published so that they can be combined with archived data? What new techniques for interferometers are coming on line? This paper contains a brief review of interferometric data analysis in the context of binary star astrometry.

The Smooth Particle Hydrodynamics (SPH) impact code (Benz & Asphaug 1994) has been developed for the simulation of impacts and collisions involving brittle solids in the strength-and gravity-dominated regime. In the latter regime, the gravitational overburden is used to increase the fracture threshold. In this paper, we extend our numerical approach to include the effect of porosity at a sub-resolution scale by adapting the so-called P -α model (Herrman 1969). Using our extended 3D SPH impact code, we investigated collisions between porous bodies to examine the sensitivity of collisional outcomes to the degree of porosity. Two applications that illustrate the capabilities of our approach are shown: 1) the modeling of a Deep Impact-like impact and 2) the computation of the amount of momentum transferred to an asteroid following the impact of a high velocity projectile.

We report on our recent efforts to compute the X-ray emission from the hot, shocked stellar wind gas filling the inner cavity of planetary nebulae. To this end, we updated our 1D hydrodynamics code NEBEL by including a module that computes the heat transfer by thermal conduction across the contact discontinuity separating the hot shocked wind gas from the much cooler nebular material. Given the temperature and density structure of the hot bubble the X-ray emission is computed by means of the CHIANTI code. We find a reasonably close agreement of the computed X-ray luminosities with recent observations of Newton-XMM and Chandra. Our simulations also predict how the X-ray emission depends on the wind luminosity and the stellar parameters.

A summary of the round table discussion following Session B on Observational Probes of Convection.

As a result of collective efforts of an Australian–New Zealand VLBI team, the first New Zealand VLBI system was developed, and a series of test observations between New Zealand and Australia conducted. The equipment and techniques used to conduct New Zealand's first VLBI observations are discussed and results of work in Australia and New Zealand to obtain fringes and the image of the source (PKS1921-231) are presented. The road map for New Zealand radio-astronomy as well as New Zealand involvement in the SKA is discussed.

We have observed the X-ray brightest planetary nebula BD +30° 3639 with the new Japanese astronomical satellite Suzaku. With its superior spectral resolution back-illuminated CCD camera, a blend of K-lines from highly ionized C, N, O elements are successfully resolved into individual species, and an extremely high relative abundance ratio of C/O $\sim$ 40 is obtained. This strongly suggests the direct measurement of the helium shell-burning products.

Bars are the most important features that redistribute angular momentum and drive secular evolution in disk galaxies. We have derived the distribution of bar strengths in spirals and the Fourier properties of early-type galaxy bars in order to evaluate recent models of bar-halo angular momentum transfer and external gas accretion. A few results are presented here.

In the past decade high resolution measurements in the infrared employing adaptive optics imaging on 10m telescopes have allowed determining the three dimensional orbits stars within ten light hours of the compact radio source at the center of the Milky Way. These observations show the presence of a three million solar mass black hole in Sagittarius A* beyond any reasonable doubt. The Galactic Center thus constitutes the best astrophysical evidence for the existence of black holes which have long been postulated, and is also an ideal ‘lab’ for studying the physics in the vicinity of such an object. Remarkably, young massive stars are present there and probably have formed in the innermost stellar cusp. Variable infrared and X-ray emission from Sagittarius A* are a new probe of the physical processes and space-time curvature just outside the event horizon.

Previous attempts to explain the observed mass–metallicity relation of galaxies invoked selective outflows that need to be tuned to the particular cases.

Here we demonstrate that the simple concept of a star-formation history (SFH) dependent galaxy-wide integrated galactic initial stellar mass function (the IGIMF) can easily and naturally explain the mass–metallicity relation.

The idea relies on the simple fact that stars form in clusters. So to construct the IGIMF one needs to add all the stellar IMFs in the clusters formed in one epoch. The SFH enters because a galaxy with a high SFR can form more-massive clusters than a galaxy with a low SFR. Dwarf galaxies therefore have, per unit stellar mass formed, far fewer if any supernovae of type II than massive galaxies.

This work rests on the recent paper by Köppen, Weidner & Kroupa (2007).