Related papers: Supersonic Line Broadening within Young and Massiv…
We numerically investigate dynamical and chemical properties of star clusters (open and globular clusters, and ``super star clusters'', SSC) formed in interacting/merging galaxies. The investigation is two-fold: (1) large-scale…
The physical structure of hot molecular cores, where forming massive stars have heated up dense dust and gas, but have not yet ionized the molecules, poses a prominent challenge in the research of high-mass star formation and…
Massive stars blow powerful winds and eventually explode as supernovae. By doing so, they inject energy and momentum in the circumstellar medium, which is pushed away from the star and piles up to form a dense and expanding shell of gas.…
When applied to the blast wave formed by the explosion of a massive star as a supernova (SN), the theory of diffusive particle acceleration at shock fronts predicts a very high energy density in cosmic rays. Almost immediately after…
Recent proper motion and parallax measurements for the pulsar PSR B1508+55 indicate a transverse velocity of ~1100 km/s, which exceeds earlier measurements for any neutron star. The spin-down characteristics of PSR B1508+55 are typical for…
There is increasing evidence that, in the very late phase of stellar evolution before core collapse, massive stars have winds with large mass loss rates that give rise to a dense circumstellar medium (CSM) surrounding the progenitor star.…
Velocity shifts and differential broadening of radio recombination lines are used to estimate the densities and velocities of the ionized gas in several hypercompact and ultracompact HII regions. These small HII regions are thought to be at…
Supernova remnants are believed to be a major source of cosmic-rays in the Galaxy. As their progenitors are commonly found clustered in OB associations, one has to consider the possibility of collective effects in the acceleration process.…
Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions around high-mass stars. Understanding their broadening mechanisms and intensity trends can provide insights into the densities,…
Subarcsecond infrared and radio observations yield important information about the formation of super star clusters from their surrounding gas. We discuss the general properties of ionized and molecular gas near young, forming SSCs, as…
Nuclear star clusters (NCs) are found to exist in the centres of many galaxies and appear to follow scaling relations similar to those of super-massive black holes. Previous analytical work has suggested that such relations are a…
About 1/3 of X-ray-luminous clusters show smooth, Mpc-scale radio emission, known as giant radio haloes. One promising model for radio haloes is Fermi-II acceleration of seed relativistic electrons by compressible turbulence. The origin of…
Nebular spectral lines provide insight into the properties of the interstellar medium (ISM) and the ionizing radiation within galaxies. The presence of high-energy ionization lines such as \heii indicates the existence of ionizing photons…
The mass reinserted by young stars of an emerging massive compact cluster shows a bimodal hydrodynamic behaviour. In the inner part of the cluster, it is thermally unstable, while in its outer parts it forms an out-blowing wind. The…
The properties of supersonic isothermal turbulence influence a variety of astrophysical phenomena, including the structure and evolution of star forming clouds. This work presents a simple model for the structure of dense regions in…
Episodic accretion plays an important role in the evolution of young stars. Although it has been under investigation for a long time, the origin of such episodic accretion events is not yet understood. We investigate the dust and gas…
So called superluminous supernovae have been recently discovered in the local Universe. It appears possible that some of them originate from stellar explosions induced by the pair instability mechanism. Recent stellar evolution models also…
Context. Massive stars are generally believed to form in supersonic turbulent environment. However, recent observations have challenged this traditional view. High spatial and spectral resolution observations of the Orion Molecular Cloud…
Quillen et al.(2007) presented an imaging survey with the {\it Spitzer Space Telescope} of 62 brightest cluster galaxies with optical line emission located in the cores of X-ray luminous clusters. They found that at least half of these…
Star clusters interact with the interstellar medium (ISM) in various ways, most importantly in the destruction of molecular star-forming clouds, resulting in inefficient star formation on galactic scales. On cloud scales, ionizing radiation…