相关论文: Formation of Ultracompact X-ray Binaries in Dense …
We know from observations that globular clusters are very efficient catalysts in forming unusual short-period binary systems or their offspring, such as low-mass X-ray binaries (LMXBs; neutron stars accreting matter from low-mass stellar…
Improved observations of globular clusters are uncovering a large number of radio pulsars and of X-ray sources. The latter include binaries in which a neutron star or a white dwarf accretes matter from a companion, recycled pulsars, and…
In contrast to the field, the binaries in dense stellar systems are frequently not primordial, and could be either dynamically formed or significantly altered from their primordial states. Destruction and formation of binaries occur in…
Dynamical interactions that occur between objects in dense stellar systems are particularly important for the question of formation of X-ray binaries. We present results of numerical simulations of 70 globular clusters with different…
A binary in which a slightly evolved star starts mass transfer to a neutron star can evolve towards ultra-short orbital periods under the influence of magnetic braking. This is called magnetic capture. We investigate in detail for which…
Observations with BeppoSAX, RXTE and Chandra suggest that many of the bright X-ray sources in globular clusters have ultrashort binary periods. This is remarkable as such systems are not easily formed. With accurate optical astrometry of…
Chandra observations of distant elliptical galaxies have revealed large numbers of Low Mass X-ray Binaries (LMXBs) accreting at rates in excess of 10^{-8} solar masses per year. The majority of these LMXBs reside in globular clusters (GCs)…
In this paper, the second of a series, we study the stellar dynamical and evolutionary processes leading to the formation of compact binaries containing neutron stars (NSs) in dense globular clusters (GCs). For this study, 70 dense clusters…
Dynamical interactions that take place between objects in dense stellar systems lead to frequent formation of exotic stellar objects, unusual binaries, and systems of higher multiplicity. They are most important for the formation of…
There have been several recent claims of black hole binaries in globular clusters. I show that these candidate systems could instead be ultracompact X-ray binaries (UCXBs) in which a neutron star accretes from a white dwarf. They would…
An X-ray flaring source was found near the galaxy NGC 4697. Two flares were seen, separated by four years. The flux increased by a factor of 90 on a timescale of about one minute. Both flares were very brief. There is no optical counterpart…
We find a remarkably enhanced production rate in star clusters (relative to the field) of very short period, massive double-white-dwarf stars and of giant-white dwarf binaries. These results are based on N-body simulations performed with…
We have investigated the effect of the number of primordial binaries on the relationship between the total number of detected binaries within globular cluster and its collision rate. We have used simulated populations of binary stars in…
The detections of four apparently young radio pulsars in the Milky Way globular clusters are difficult to reconcile with standard neutron star formation scenarios associated with massive star evolution. Here we discuss formation of these…
Repeatedly flaring X-ray binaries have recently been discovered in NGC 4697 by Sivakoff and collaborators. We show that these flares can be explained as the result of eccentric binaries in globular clusters which accrete more rapidly at…
We study the formation of neon-enriched donor stars in ultracompact X-ray binaries (orbital periods P<80 min) and show that their progenitors have to be low-mass (0.3 - 0.4 solar mass) ``hybrid'' white dwarfs (with CO cores and thick helium…
A binary in which a slightly evolved star starts mass transfer to a neutron star can evolve towards ultra-short orbital periods under the influence of magnetic braking. This is called magnetic capture. We investigate in detail for which…
The importance of stellar encounters in producing stellar exotica in dense stellar clusters is reviewed. We discuss how collisions between main-sequence stars may be responsible for the production of blue stragglers in globular clusters. We…
Luminous X-ray binaries (>1E34 erg/s, LMXBs) have a neutron star or black hole primary, and in globular clusters, most of these close binaries are expected to be have evolved from wider binaries through dynamical interactions with other…
Globular clusters are dense stellar systems that have typical ages of ~13 billion years, implying that they formed at redshifts of z>~6. Massive stars in newly formed or primordial globular clusters could have played an important role…