Related papers: Bounds on Expected Black Hole Spins in Inspiraling…
Using recent results from numerical relativity simulations of black hole mergers, we revisit previous studies of cosmological black hole spin evolution. We show that mergers are very unlikely to yield large spins, unless alignment of the…
In this work, we investigate an alternative channel for the formation of fast-spinning black hole-neutron star (BHNS) binaries, in which super-Eddington accretion is expected to occur in accreting BHs during the stable mass transfer phase…
We consider a subset of the physical processes that determine the spin j = a/M of astrophysical black holes. These include: (1) Initial conditions. Recent models suggest that the collapse of supermassive stars are likely to produce black…
We review current challenges in understanding the values and origin of the spins of black holes in binaries. Thanks to recent advances in astrophysical instrumentation, the spins can now be measured using both gravitational waves emitted by…
Black hole-neutron star (BHNS) binaries are important sources of gravitational waves for second-generation interferometers, and BHNS mergers are also a proposed engine for short, hard gamma-ray bursts. The behavior of both the spacetime…
The spin of a number of black holes (BHs) in binary systems has been measured. In the case of BHs found in low-mass X-ray binaries (LMXBs) the observed values are in agreement with some theoretical predictions based on binary stellar…
We present general relativistic magneto-hydrodynamical simulations of equal-mass spinning black hole binary mergers embedded in a magnetized gas cloud. We focus on the effect of the spin orientation relative to the orbital angular momentum…
The spin precession of binary black holes (BBHs) that originate from isolated high-mass binary stars is determined by the interplay of phenomena such as tides, winds, accretion, common-envelope evolution, natal kicks, and stellar…
The formation environments of merging binary black holes remain uncertain. While hierarchical assembly in dense stellar clusters has been widely explored as an explanation for black holes exceeding the stellar-mass limit, growth through gas…
During the fourth observing run, the LIGO-Virgo-KAGRA Collaboration reported the detection of a coalescing compact binary (GW230529$_{-}$181500) with component masses estimated at $2.5-4.5\, M_\odot$ and $1.2-2.0\, M_\odot$ with 90\%…
Interactions between a supermassive black hole binary and the surrounding accretion disc can both assist the binary inspiral and align the black hole spins to the disc angular momentum. While binary migration is due to angular-momentum…
The spin of a black hole is an important quantity to study, providing a window into the processes by which a black hole was born and grew. Further, spin can be a potent energy source for powering relativistic jets and energetic particle…
GW231123, the most massive binary black hole (BBH) merger detected by LIGO/Virgo/KAGRA, highlights the need to understand the origins of massive, high-spin stellar black holes (BHs). Dense star clusters provide natural environments for…
We investigate the accretion induced spin up of the black hole via numerical simulations. Our method is based on general-relativistic magneto-hydrodynamics of the slowly-rotating flows in the Kerr metric, where possibly transonic shock…
Galactic field black hole (BH) low-mass X-ray binaries (LMXBs) are believed to form in situ via the evolution of isolated binaries. In the standard formation channel, these systems survived a common envelope phase, after which the remaining…
In this work, we use general relativistic magnetohydrodynamics simulations to explore the effect of spin orientation on the dynamics of gas in the vicinity of merging black holes. We present a suite of eight simulations of unequal-mass,…
Observations of gravitational waves and their electromagnetic counterparts may soon uncover the existence of coalescing compact binary systems formed by a stellar-mass black hole and a neutron star. These mergers result in a remnant black…
As 2 black holes bound to each other in a close binary approach merger their inspiral time becomes shorter than the characteristic inflow time of surrounding orbiting matter. Using an innovative technique in which we represent the changing…
Angular momentum transport in high-mass stars is commonly modeled by extrapolating the behavior of better-observed low-mass stars. According to the conventional picture, the cores of most black hole progenitors lose almost all of their…
The origin of current angular momentum (AM) of the black hole (BH) in X-ray binary (XRB) is still unclear, which is related with the birth and/or the growth of the BH. Here we collect the spin parameters $a_{*}$ measured in BH XRBs and find…