相关论文: A new rare type of supernovae: hypervelocity stell…
Binary star systems containing a neutron star or a black hole with an evolved, massive star are dynamically perturbed when the latter undergoes a supernova explosion. It is possible that the natal kick received by the newly-formed neutron…
Centers of galaxies host both a supermassive black hole and a dense stellar cluster. Such an environment should lead to stellar collisions, possibly at very high velocities so that the total energy involved is of the same order as…
The enormous velocities of the so called hypervelocity stars (HVSs) derive, likely, from close interactions with massive black holes, binary stars encounters or supernova explosions. In this paper, we investigate the origin of hypervelocity…
In galactic centers, stars and binaries can be injected into low-angular-momentum orbits, resulting in close encounters with the central supermassive black hole (SMBH). Previous works have shown that under different conditions, such close…
High-velocity stellar collisions near supermassive black holes may result in a complete disruption of the stars. The initial disruption can have energies on par with supernovae and power a very fast transient. In this work we examine the…
The high stellar densities in young compact star clusters, such as the star cluster R 136 in the 30 Doradus region, may lead to a large number of stellar collisions. Such collisions were recently found to be much more frequent than previous…
A star on a nearly radial trajectory approaching a massive black hole (MBH) gets tidally disrupted if it comes sufficiently close to the MBH. Here we explore what happens to binary stars whose centers of mass approach the MBH on nearly…
High velocity stars are stars moving at velocities so high to require an acceleration mechanism involving binary systems or the presence of a massive central black hole. In the frame of a galaxy hosting a supermassive black hole binary (of…
The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black…
When two stars collide and merge they form a new star that can stand out against the background population in a starcluster as a blue straggler. In so called collision runaways many stars can merge and may form a very massive star that…
One possible origin of high velocity stars in the Galaxy is that they are the product of the interaction of binary systems and supermassive black holes. We investigate a new production channel of high velocity stars as due to the close…
A bright flare from a galactic nucleus followed at late times by a $t^{-5/3}$ decay in luminosity is often considered the signature of the complete tidal disruption of a star by a massive black hole. The flare and power-law decay are…
The presence of young massive stars orbiting on eccentric rings within a few tenths of a parsec of the supermassive black hole in the Galactic centre is challenging for theories of star formation. The high tidal shear from the black hole…
Close encounters and physical collisions between stars in young dense clusters may lead to the formation of very massive stars and black holes via runaway merging. We examine critically some details of this process, using N-body simulations…
Recent surveys have identified seven hypervelocity stars (HVSs) in the halo of the Milky Way. Most of these stars may have originated from the breakup of binary star systems by the nuclear black hole SgrA*. In some instances, the breakup of…
The disruption of a binary star system by the massive black hole at the Galactic Centre, SgrA*, can lead to the capture of one star around SgrA* and the ejection of its companion as a hypervelocity star (HVS). We consider the possibility…
Close encounters and physical collisions between stars in young dense clusters can result in new channels for stellar evolution, and may lead to the formation of very massive stars and black holes via runaway merging. We present some…
A diverse range of phenomena is possible when a black hole experiences very rapid accretion from a disk due to the incomplete explosion of a massive presupernova star endowed with rotation. In the most extreme case, the outgoing shock fails…
Dense stellar clusters surround the supermassive black holes (SMBH) in galactic nuclei. Interactions within the cluster can alter the stellar orbits, occasionally driving a star into the SMBH's tidal radius where it becomes ruptured, or…
Observations show the presence, in the halo of our Galaxy, of stars moving at velocities so high to require an acceleration mechanism involving the presence of a massive central black hole. Thus, in the frame of a galaxy hosting a…