Related papers: Self-Consistent Evolution of Ring Galaxies
The existence or otherwise of X-ray luminous star-forming galaxies has been an open question since the era of the Einstein satellite. Various authors have claimed the discovery of X-ray luminous star-forming galaxies but in many cases more…
We present here the first study of the X-ray properties of an evolutionary sample of merging galaxies. Both ROSAT PSPC and HRI data are presented for a sample of eight interacting galaxy systems, each believed to involve a similar encounter…
Rapidly rotating stars are readily produced in binary systems. An accreting star in a binary system can be spun up by mass accretion and quickly approach the break-up limit. Mergers between two stars in a binary are expected to result in…
The amount and nature of the evolution of the X-ray properties of clusters of galaxies provides information on the formation of structure in the universe and on the properties of the universe itself. The cluster luminosity - temperature…
Integrated X-ray spectra of an evolving population of starburst galaxies (SBGs) are determined based on the observed spectra of local SBGs. In addition to emission from hot gas and binary systems, our model SBG spectrum includes a…
Twenty-four galaxies with rings or partial rings were studied in the GEMS and GOODS fields out to z~1.4. Most resemble local collisional ring galaxies in morphology, size, and clumpy star formation. Clump ages range from 10^8 to 10^9 yr and…
Irregular (Irr) galaxies are gas-rich objects with recent or ongoing star formation. In absence of spiral density waves, star formation occurs largely stochastically. The scattered star-forming regions tend to be long-lived and migrate…
The clusters of gamma-ray bursts are considered which are assumed to be images of the repeated gamma-ray burst (GRB) sources. It is shown, that localization of the cosmic gamma-ray burst sources (GBS) is determined by the clusters of GRBs.…
Although starburst galaxies have relatively flat spectral energy distributions, their strong optical emission lines and near-UV continua make it very feasible to estimate their redshifts photometrically. In this work, I describe a…
In order to understand nature of building blocks of galaxies in the early universe, we investigate "genuine irregular galaxies (GIGs)" in the nearby universe. Here, GIGs are defined as isolated galaxies without regular structures (spheroid,…
A detailed understanding of the physics of star and planet formation requires study of individual objects as well as statistical assessment of global properties and evolutionary trends. Observational investigations of circumstellar material…
Present knowledge indicates that gamma-ray bursts are linked with massive stars. They will become invaluable probes of the early universe and galaxy formation. In the future, it will be possible to use gamma-ray bursts for two purposes: 1)…
Young clusters are observed to form in a variety of interacting galaxies and violent starbursts, a substantial number resembling the progenitors of the well-studied globular clusters in mass and size. By studying young clusters in merger…
B[e] Supergiants are a phase in the evolution of some massive stars for which we have observational evidence but no predictions by any stellar evolution model. The mass-loss during this phase creates a complex circumstellar environment with…
Massive stars lose a large fraction of their original mass over the course of their evolution. These stellar winds shape the surrounding medium according to parameters that are the result of the characteristics of the stars, varying over…
A significant fraction of clusters of galaxies are observed to have substructure, which implies that merging between clusters and subclusters is a rather common physical process of cluster formation. It still remains unclear how cluster…
Giant low surface brightness galaxies (GLSBs) have flat discs extending up to ~100 kpc. Their formation is a puzzle for cosmological simulations in the cold dark matter scenario. We suggest that GLSBs might be the final product of the…
The evolution of irregular galaxies is examined from two points of view: on the one hand, models of galactic chemical evolution have been computed and their predictions compared with the corresponding observational data on the element…
Lyman break galaxies (LBGs) at $z \sim 3$ exhibit number densities and clustering similar to local $L_*$ galaxies; however, their star formation rates (SFRs) are much higher. We explore the scenario in which LBGs are starburst galaxies…
The centers of most galaxies in the local universe are occupied by compact, barely resolved sources. Based on their structural properties, position in the fundamental plane, and integrated spectra, these sources clearly have a stellar…