Related papers: Super-massive stars: Radiative transfer
A ring of dense molecular gas extending 2-7 pc orbits the supermassive black hole Sgr A* at the center of our Galaxy. Using the Green Bank Telescope, we detected water maser lines and both narrow (0.35 km/s) and broad (30 - 50 km/s)…
From the main sequence to their late evolutionary stages, massive stars spend most of their life as hot stars. Due to their high effective temperatures, the maximum of their emitted flux falls into the ultraviolet (UV) regime. Consequently,…
Mergers of neutron stars (NS+NS) or neutron stars and stellar mass black holes (NS+BS) eject a small fraction of matter with a sub-relativistic velocity. Upon rapid decompression nuclear density medium condenses into neutron rich nuclei,…
We follow the collapse in axisymmetry of a uniformly rotating, supermassive star (SMS) to a supermassive black hole (SMBH) in full general relativity. The initial SMS of arbitrary mass $M$ is marginally unstable to radial collapse and…
Observations of transient phenomena in the Universe reveal a spectrum of mass-ejection properties associated with massive stars, covering from Type II/Ib/Ic core-collapse supernovae (SNe) to giant eruptions of Luminous Blue Variables (LBV)…
Astronomical observations reveal a gap in the mass spectrum of relativistic objects: neither black holes nor neutron stars with 2 - 5 solar masses have ever been observed. In this article I proceed in presenting the scenario which discloses…
We study the impact of heavy dark matter (DM) captured in massive stars via scattering(s) with the star constituents. We focus on the first stars and use stellar evolution simulations to track down how DM capture evolves over time from the…
Models of superdense star clusters at the center of galaxies are investigated to see whether such objects can be stable and long-lived based on evaporation and collision time-scales and stability criteria. We find that physically reasonable…
Supermassive black hole accretion and star formation appear intimately connected. I review the observational and theoretical evidence for this statement. I then discuss how focussed studies of two systems, our Galactic Center and the…
We develop a method of analyzing radio frequency spectral line observations to derive data on the temperature, density, velocity, and molecular abundance of the emitting gas. The method incorporates a radiative transfer code with a new…
Supermassive black holes are thought to be relics of quasars, and their numbers and masses are therefore related to the quasar luminosity function and its evolution with redshift. We have used the relationship between black hole mass and…
The pressure exerted by massive stars' radiation fields is an important mechanism regulating their formation. Detailed simulation of massive star formation therefore requires an accurate treatment of radiation. However, all published…
Nuclear reactions transform atomic nuclei inside stars. This is the process of stellar nucleosynthesis. The basic concepts of determining nuclear reaction rates inside stars are reviewed. How stars manage to burn their fuel so slowly most…
Massive stars (M> 10Msun) end their lives with spectacular explosions due to gravitational collapse. The collapse turns the stars into compact objects such as neutron stars and black holes with the ejection of cosmic rays and heavy…
Direct collapse of supermassive stars (SMSs) is a possible pathway for generating supermassive black holes in the early universe. It is expected that an SMS could form via very rapid mass accretion with Mdot ~ 0.1 - 1 Msun/yr during the…
The evolution of a binary star system by various analytic approximations of mass transfer is discussed, with particular attention payed to the stability of these processes against runaway on the thermal and dynamical timescales of the mass…
The early evolution of dense stellar systems is governed by massive single star and binary evolution. Core collapse of dense massive star clusters can lead to the formation of very massive objects through stellar collisions ($M\geq$ 1000…
One of the most promising explanations for the origin of the billion solar mass black holes (BHs) inferred to power quasars at redshifts z > 6 is that supermassive stars (SMSs) with masses > 10,000 solar masses collapse to form the seed BHs…
Supermassive stars (SMS) with masses $M \gtrsim 10^3-10^4 M_{\odot}$, formed by runaway collisions in young, massive, and dense star clusters have been invoked as a possible solution to the puzzles raised by the presence of multiple stellar…
This is a pedagogical review of recent results on the interactions of central massive black holes with stars very near them, focused on the black hole in the center of the Milky Way. Table of contents: [1] Introduction [2] Stellar dynamics…