Related papers: Black-Hole Spin Dependence in the Light Curves of …
Clumps of material orbiting a black hole may be disturbed, somewhat like comets in the Kuiper belt, to relatively small periastron orbits. Each periastron passage changes the orbital parameters in such a way that the orbit becomes more and…
We develop a Newtonian model of a deep tidal disruption event (TDE), for which the pericenter distance of the star, $r_{\rm p}$, is well within the tidal radius of the black hole, $r_{\rm t}$, i.e., when $\beta \equiv r_{\rm t}/r_{\rm p}…
Accretion onto black holes is an efficient mechanism in converting the gas mass-energy into energetic outputs as radiation, wind and jet. Tidal disruption events, in which stars are tidally torn apart and then accreted onto supermassive…
An important issue in the dynamics of neutron star binaries is whether tidal interaction can cause the individual stars to collapse into black holes during inspiral. To understand this issue better, we study the dynamics of a cluster of…
To complement hydrodynamic studies of the tidal disruption of the star by a massive black hole, we present the study of stellar luminosity and its variations, produced by the strong gravitational field of the black hole during a close…
Galactic center black holes appear to be nearly universally surrounded by dense stellar clusters. When these black holes go through an active accretion phase, the multiple components of the accretion disk, stellar cluster, and black hole…
The apparent angular size of the shadow of a black hole in an expanding Universe is redshift-dependent. Since cosmological redshifts change with time - known as the redshift drift - all redshift-dependent quantities acquire a…
Here we consider two phenomena in the vicinity of a black hole deformed by the tidal gravitational force of surrounding matter and by a strong magnetic field: equatorial motion of charged particles and the decay of a test scalar field. We…
Many astrophysical environments, from star clusters and globular clusters to the disks of Active Galactic Nuclei, are characterized by frequent interactions between stars and the compact objects that they leave behind. Here, using a suite…
Tidal disruption events (TDEs) occur when a star, passing too close to a massive black hole, is ripped apart by tidal forces. A less dramatic event occurs if the star orbits just outside the tidal radius, resulting in a mild stripping of…
A star completely destroyed in a tidal disruption event (TDE) ignites a luminous flare that is powered by the fallback of tidally stripped debris to a supermassive black hole (SMBH) of mass $M_{\bullet}$. We analyze two estimates for the…
The tidal disruption of a star by a supermassive black hole (SMBH) is a highly energetic event with consequences dependent on the degree to which the star plunges inside the SMBH's tidal sphere. We introduce a new analytic model for tidal…
In the standard paradigm, astrophysical black holes can be described solely by their mass and angular momentum - commonly referred to as `spin' - resulting from the process of their birth and subsequent growth via accretion. Whilst the mass…
A star is tidally disrupted by a supermassive black hole when their separation is shorter than the "tidal radius". This quantity is often estimated on an order-of-magnitude basis without reference to the star's internal structure. Using…
We present simulations of the tidal disruption of a solar mass star by a $10^6M_{\odot}$ black hole. These, for the first time, cover the full time evolution of the tidal disruption event, starting well before the initial encounter and…
The orbits of stars close to a massive black hole are nearly Keplerian ellipses. Such orbits exert long term torques on each other, which lead to an enhanced angular momentum relaxation known as resonant relaxation. Under certain…
Close encounters between stellar-mass black holes (BHs) and stars occur frequently in dense star clusters and in the disks of active galactic nuclei (AGNs). Recent studies have shown that in highly eccentric close encounters, the star can…
The defining feature of a classical black hole is being a perfect absorber. Any evidence showing otherwise would indicate a departure from the standard black-hole picture. Energy and angular momentum absorption by the horizon of a black…
We perform hydro- and magnetohydrodynamical general relativistic simulations of a tidal disruption of a $0.1\,M_\odot$ red dwarf approaching a $10^5\,M_\odot$ non-rotating massive black hole on a close (impact parameter $\beta=10$)…
Highly energetic stellar tidal disruption events (TDEs) provide a way to study black hole characteristics and their environment. We simulate TDEs with the PHANTOM code in a general relativistic and Newtonian description of a supermassive…