Related papers: Black Hole Spin-Orbit Misalignment in Galactic X-r…
We discuss the timescales for alignment of black hole and accretion disc spins in the context of binary systems. We show that for black holes that are formed with substantial angular momentum, the alignment timescales are likely to be at…
Very wide binaries (> 500 AU) are subject to numerous encounters with flying-by stars in the Galactic field and can be perturbated into highly eccentric orbits (e ~ 0.99). For such systems tidal interactions at close pericenter passages can…
We calculate the formation rates of low-mass X-ray binaries with a black hole. Both a semi-analytic and a more detailed model predict formation rates two orders of magnitude lower than derived from the observations. Solution of this…
Merging binary black holes (BBHs) formed dynamically in dense star clusters are expected to have uncorrelated spin--orbit orientations since they are assembled through many random interactions. However, measured effective spins in BBHs…
The origin of black hole (BH) spins remains one of the least understood aspects of BHs. Despite many uncertainties, it is commonly assumed that if BHs originated from isolated massive star binaries, their spins should be aligned with the…
Understanding the formation mechanisms of stellar-mass black holes in X-ray binaries (BHXBs) remains a fundamental challenge in astrophysics. The natal kick velocities imparted during black hole formation provide crucial constraints on…
Black hole-neutron star mergers resulting in the disruption of the neutron star and the formation of an accretion disk and/or the ejection of unbound material are prime candidates for the joint detection of gravitational-wave and…
We investigate the evolution of low mass (Md /Mb = 0.005) misaligned gaseous discs around eccentric supermassive black hole (SMBH) binaries. These are expected to form from randomly oriented accretion events onto a SMBH binary formed in a…
Theoretical and observational studies suggest that stellar binaries exist in large numbers in galactic nuclei like our own Galactic Center. Neutron stars (NSs), and debatedly, black holes (BHs) and white dwarfs (WDs), receive natal kicks at…
Be stars are rapidly spinning B stars surrounded by an outflowing disc of gas in Keplerian rotation. Be star/X-ray binary systems contain a Be star and a neutron star. They are found to have non-zero eccentricities and there is evidence…
Compact binary coalescences are the most promising sources of gravitational waves (GWs) for ground based detectors. Binary systems containing one or two spinning black holes are particularly interesting due to spin-orbit (and eventual…
Merging compact black-hole (BH) binaries are likely to exist in the nuclear star clusters around supermassive BHs (SMBHs), such as Sgr A$^\ast$. They may also form in the accretion disks of active galactic nuclei. Such compact binaries can…
Spin parameters of stellar-mass black holes in X-ray binaries are currently being estimated by fitting the X-ray continuum spectra of their accretion disk emission. For this method, it is necessary to know the inclination of the…
We present a study of spinning black hole binaries focusing on the spin dynamics of the individual black holes as well as on the gravitational recoil acquired by the black hole produced by the merger. We consider two series of initial spin…
We model the overall shape of an accretion disc in a semi-detached binary system in which mass is transfered on to a spinning black hole the spin axis of which is misaligned with the orbital rotation axis. We assume the disc is in a steady…
If a black hole has a low spin value, it must double its mass to reach a high spin parameter. Although this is easily accomplished through mergers or accretion in the case of supermassive black holes in galactic centers, it is impossible…
The spins of black holes in merging binaries can reveal information related to the formation and evolution of these systems through their gravitational wave emission. Combining events to infer the astrophysical distribution of black hole…
Mass distribution of black holes in low-mass X-ray binaries previously suggested the existence of a $ \sim 2-5M_{\odot} $ mass gap between the most massive neutron stars and the least massive black holes, while some recent evidence appears…
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…
Close stellar binaries are prone to undergo a phase of stable mass transfer in which a star loses mass to its companion. Assuming that the donor star loses mass along the instantaneous interstellar axis, we derive the orbit-averaged…