Related papers: Why Are Ring Galaxies Interesting?
The presence of spiral structure in isolated galaxies is a problem that has only been partially explained by theoretical models. Because the rate and pattern of star formation in the disk must depend only on mechanisms internal to the disk,…
The kinematics of galactic rings were studied with a scanning Fabry-Perot interferometer mounted in the multi-mode focal reducer SCORPIO (Afanasiev & Moiseev 2005) at the SAO RAS 6-m telescope. The analysis of the ionized gas velocity…
Understanding star formation is problematic as it originates in the large scale dynamics of a galaxy but occurs on the small scale of an individual star forming event. This paper presents the first numerical simulations to resolve the star…
In the first part of this article, we review observations of the mass and luminosity functions of young and old star cluster systems. We also review some of the physical processes that may determine the characteristic mass of globular…
Young stars form on a wide range of scales, producing aggregates and clusters with various degrees of gravitational self-binding. The loose aggregates have a hierarchical structure in both space and time that resembles interstellar…
Secular evolution gradually shapes galaxies by internal processes, in contrast to early cosmological evolution which is more rapid. An important driver of secular evolution is the flow of gas from the disk into the central regions, often…
The origin and types of spiral arms are reviewed with an emphasis on the connections between these arms and star formation. Flocculent spiral arms are most likely the result of transient instabilities in the gas that promote dense cloud…
Feedback to the interstellar medium (ISM) from ionising radiation, stellar winds and supernovae is central to regulating star formation in galaxies. Due to their low mass ($M_{*} < 10^{9}$\,M$_\odot$), dwarf galaxies are particularly…
Galaxies with Milky Way-like stellar masses have a wide range of bulge and black hole masses; in turn, these correlate with other properties such as star formation history. While many processes may drive bulge formation, major and minor…
Quenched massive spiral galaxies have attracted great attention recently, as more data is available to constrain their environment and cold gas content. However, the quenching mechanism is still uncertain, as it depends on the mass range…
The question whether magnetic fields play an important role in the processes of molecular cloud and star formation has been debated for decades. Recent observations have revealed a simple picture that may help illuminate these questions:…
Rotation has a number of important effects on the evolution of stars. Apart from structural changes because of the centrifugal force, turbulent mixing and meridional circulation caused by rotation can dramatically affect a star's chemical…
Polar ring galaxies are flattened stellar systems with an extended ring of gas and stars rotating in a plane almost perpendicular to the central galaxy. We show that their formation can occur naturally in a hierarchical universe where most…
We study influence by models of inter-stellar medium (ISM) on properties of galaxies in cosmological simulations. We examine three models widely used in previous studies. The ISM models impose different equations of state on dense gas.…
Star clusters that form in nuclear rings appear to be at slightly larger radii than the gas. We argue that the star clusters move out from the gas in which they are formed because of satellite-disk tidal interactions. In calculating the…
Globular clusters are large and dense agglomerate of stars. At variance with smaller clusters of stars, they exhibit signs of some chemical evolution. At least for this reason, they are intermediate between open clusters and massive objects…
We review the physics of star formation, and its links with the state of the ISM in galaxies. Current obervations indicate that the preferred mode of star formation is clustered. Given that OB associations provide the dominant energy input…
The effects of rapid rotation on stellar evolution can be profound. We are now beginning to gather enough data to allow a realistic comparison between different physical models. Two key tests for any theory of stellar rotation are first…
Magnetic fields are an elemental part of the interstellar medium in galaxies. However, their impact on gas dynamics and star formation in galaxies remains controversial. We use a suite of global magnetohydrodynamical simulations of isolated…
Until recently, simulations that modeled entire galaxies were restricted to an isothermal or fixed 2- or 3-phase interstellar medium (ISM). This obscured the full role of the ISM in shaping the observed galactic-scale star formation…