The research of early evolution stages and formation of galaxies requires creation of appropriate non-linear theory. The formation process of globular cluster systems (GCS) covers the long period of time as probably one begins from a dark matter state. So far it is difficult to simulate formation of GCS and galaxies ab initio. That’s why it is necessary to construct exact analytically solvable models of non-linear non-stationary early stages of evolution of self-gravitating systems and revealing the instabilities on a background of non-equilibrium states. The formation and evolution of GCS at early stage of collapsing dark matter (or protogalaxy) can be explained by instability of the modes of the high oscillation degrees (Nuritdinov et al., 2000), which corresponds to rather small-scale perturbations of the density of collapsing system. The mode degree defines on the average the number of clusters.

High resolution studies reveal that luminous young stellar clusters and their associations are ubiquitous within 1 kpc of ULIRGs, and could be the precursors to globular clusters. We have undertaken a study of the ages, masses, extinction, and dust properties of the clusters found in the brightest ULIRG in the extended IRAS BGS Sample, IRAS 17208–0014, using it as a unique system in which to study the formation and evolution of clusters in gas-rich mergers. Using NICMOS JHK and WFPC2 I–band images, we have compared the near-IR colors of the clusters with those expected from a Bruzual & Chariot model. There are a few clusters whose colors can be explained by moderate values of extinction (1 – 3 mag), but others require some contribution from hot (400 – 1000 K) dust. We derive ages of a few tens of Myr and masses from 106 to 107 M⊙. These clusters may be supermassive compared to globular clusters, or could be unresolved associations of clusters.

Recently, a number of possible young globular clusters (GCs) have been found in some merging/interacting galaxies or starburst galaxies. On the other hand, it is well known that GCs are numerous in giant elliptical galaxies many of which are thought to be formed via major merger of galaxies. These facts lead us to a thought that the formation process of GCs could accompany galaxy – galaxy interaction followed by starburst. The archetypical starburst galaxy M82 is an ideal target to study the relation between galaxy interaction, starburst, and GC formation.

Abundances of 21 chemical elements have been determined in three red giants in Terzan 7 using high-resolution spectra obtained with the UVES spectrograph on the ESO 8.2 m Kueyen telescope. The mean [Fe/H]= –0.61 ±0.07. The relative elemental abundance ratios indicate a close similarity of Terzan 7 to its host galaxy.

We summarize here the oral contributions given at the Joint Discussion (JD) 7 The Sun and the Heliosphere as an Integrated System, held on July 17, 2003, in Sydney, as part of IAU XXV and give a list of posters presented at the JD.

Very Large scale telescopes and virtual observatories have in common to be global facilities, which will enable entirely new types of sciences and will require new technical and operational philosophies. Joint discussion 8 was built with a series of invited reviews to set the long term vision and challenges, and specific projects or technical topics were presented in the poster session which was also a very important part of the meeting. To keep track of all the contributions, these proceedings contain the abstracts of all papers, invited reviews and accepted contributed posters, with a few extended abstracts.

Even in the new millenium, many astronomical objects cannot be resolved spatially with any available telescope. Most stars are too small and galaxies are too far away to be imaged directly or in detail in the foreseeable future. However, advances in data-analysis techniques allow us now to create detailed indirect images using tomographic methods. These images provide unprecedented insights into fundamental processes that drive the evolution of stars and galaxies, such as accretion and magnetic-field generation, on length scales that are of great physical importance but which are otherwise inaccessible.

Joint Discussion 09 was held on two half-days during the General Assembly. The main proceedings will be published in full in a special issue of Astronomische Nachrichten, to which the reader is referred, early in 2004. Here we give only a brief listing of subjects addressed and the titles of talks presented at the meeting.

I present a brief review of studies of galaxy clusters in the optical. Clusters of galaxies were historically detected in the optical, and this selection provided the first large, statistical samples of clusters. I describe how these samples have been instrumental in characterizing the properties of the local cluster population, tracing large scale structure, and constraining cosmology. More sophisticated cluster detection techniques in the optical have now made it possible to detect large numbers of clusters up to z ~ 1.4. I describe these advances and discuss how large-area and deep surveys are being used to determine the evolution in the global cluster properties and the properties of cluster galaxy populations.

Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Mergers drive shocks in the intra-cluster gas which heat the intra-cluster gas. Mergers disrupt cluster cooling cores. Mergers produce large, temporary increases in the X-ray luminosities and temperatures of cluster; such merger boost may bias estimates of cosmological parameters from clusters. Chandra observations of the X-ray signatures of mergers, particularly “cold fronts,” will be discussed. X-ray observations of shocks can be used to determine the kinematics of the merger. As a result of particle acceleration in shocks and turbulent acceleration following mergers, clusters of galaxies should contain very large populations of relativistic electrons and ions. Observations and models for the radio, extreme ultraviolet, hard X-ray, and gamma-ray emission from non-thermal particles accelerated in these shocks are described.

In this brief overview of the stellar populations of galaxies in clusters I highlight some of the most recent results, including the downsizing of the k+a population and the star formation-local density relation. I conclude discussing some open questions regarding the interpretation of the observational results, and speculating on the current meaning of the words “primordial” and “environmental”.

Powerful radio sources are efficient probes of dense regions throughout the universe, including clusters of galaxies. The status of cluster searches around radio sources is reviewed, including new evidence that cluster environments affect radio morphology.

Recent data have radically altered the X-ray perspective on cooling flow clusters. X-ray spectra show that very little of the hot intra-cluster medium is cooler than about 1 keV, despite having short cooling times. In an increasing number of cooling flow clusters, the lobes of a central radio source are found to have created cavities in the hot gas. Generally, the cavities are not overpressured relative to the intra-cluster gas, but act as buoyant bubbles of radio emitting plasma that drive circulation as they rise, mixing and heating the intra-cluster gas. All this points to the radio source, i.e., an active galactic nucleus, as the heat source that prevents gas from cooling to low temperatures. However, heating due to bubbles alone seems to be insufficient, so the energetics of cooling flows remain obscure. We briefly review the data and theory supporting this view and discuss the energetics of cooling flows.

We review briefly the general properties of halo and relic sources in galaxy clusters. We also present a polarized radiative transfer algorithm which is useful for calculations of polarized radio emission from halos, relics and active galaxies in a magnetized intra-cluster medium.

Evidence for non-thermal activity in clusters of galaxies is well established from radio observations of synchrotron emission by relativistic electrons, and new windows (in EUV and Hard X-ray ranges) have provided more powerful tools for its investigation. The hard X-ray observations, notably from Coma, are summarized and results of a new RXTE observations of a high red-shift cluster are presented. It is shown that the most likely emission mechanism for these radiations is the inverse Compton scattering of the cosmic microwave background photons by the same electrons responsible for the radio radiation. Various scenarios for acceleration of the electrons are considered and it is shown that the most likely model is episodic acceleration by shocks or turbulence, presumably induced by merger activity, of high energy electrons injected into the inter-cluster medium by galaxies or active galactic nuclei.

Magnetic fields in galaxy clusters can be investigated using a variety of techniques. Recent studies including radio halos, Inverse Compton hard X-ray emissions and Faraday rotation measure, are briefly outlined. A numerical approach for investigating cluster magnetic fields strength and structure is presented. It consists of producing simulated rotation measure, radio halo images, and radio halo polarization, obtained from 3-dimensional multi-scale cluster magnetic field models, and comparing with observations.

Simulations of dense stellar systems currently face two major hurdles, one astrophysical and one computational. The astrophysical problem lies in the fact that several major stages in binary evolution, such as common envelope evolution, are still poorly understood. The best we can do in these cases is to parameterize our ignorance, in a way that is reminiscent of the introduction of a mixing length to describe convection in a single star, or an alpha parameter in modeling an accretion disk. The hope is that by modeling a whole star cluster in great detail, and comparing the results to the wealth of observational data currently available, we will be able to constrain the parameters that capture the unknown physics. The computational problem is one of composition: while we have accurate computer codes for modeling stellar dynamics, stellar hydrodynamics, and stellar evolution, we currently have no good way to put all this knowledge together in a single software environment. A year ago, a loosely-knit organization was founded to address these problems, MODEST for Modeling DEnse STellar systems, with nine working groups and a series of meetings that are held every half year. This report reviews the first year of this initiative. Much more detail can be found on the MODEST web site http://www.manybody.org/modest.html.

I overview the current understanding of the evolution of massive black hole (MBH) binaries in the center of the host stellar system. One of the main questions is whether the stellar dynamical effect can make the MBH binary hard enough that they can merge through gravitational wave radiation. So far, theories and numerical simulations suggested otherwise, since the hardening time scale becomes very long once ”loss cone” is depleted. I’ll present the result of recent simulations on this hardening time scale, and discuss its implication on the formation history of massive black holes.

We use N-body simulations to follow the evolution of bars in the presence of a central mass concentration (CMC). We find that the bar amplitude decreases in response to the CMC, but the bar is not totally destroyed unless the CMC mass is several percent of that of the disc. More centrally concentrated CMCs are more efficient. The bar evolution does not stop after the CMC has fully grown, but continues well after that time.