Related papers: A maximum X-ray luminosity scale of disc-dominated…
The early time emission in tidal disruption events (TDEs) originates from both accretion and shocks, which produce photons that eventually emerge from an inhomogeneous photosphere. In this work, we model the disk formation following the…
Observations of luminous flares resulting from the possible tidal disruption of stars by supermassive black holes have raised a number of puzzles. Outstanding questions include the origin of the optical and ultraviolet (UV) flux, the…
Tidal disruption events are routinely discovered as bright optical/UV flares, the properties of which are now well categorized on the population level. The underlying physical processes that produce the evolution of their X-ray emission and…
We report results from general relativistic radiation MHD (GRRMHD) simulations of a super-Eddington black hole (BH) accretion disk formed as a result of a tidal disruption event (TDE). We consider the fiducial case of a solar mass star on a…
The evolution of an accretion disk, formed as a consequence of the disruption of a star by a black hole, is followed by solving numerically the hydrodynamic equations. The present investigation aims to study the dependence of resulting…
During a close encounter between a star and a supermassive black hole, the star can get disrupted by the black hole's tidal forces, resulting in a tidal disruption event (TDE). The accretion of the star's material onto the black hole…
Observations of tidal disruption events (TDEs) on a timescale of years after the main flare show evidence of continued activity in the form of optical/UV emission, quasi-periodic eruptions, and delayed radio flares. Motivated by this, we…
Quasars accretion models predict a broad range of optical and ultraviolet properties that depend primarily on black hole mass and accretion rate. Yet, most optically selected luminous quasars display strikingly similar continuum spectra. We…
The classical radiation pressure instability has been a persistent theoretical feature of thin, radiatively efficient accretion disks with accretion rates 1 to 100 per cent of the Eddington rate. But there is only limited evidence of its…
Although we are nearing a consensus that most ULXs are stellar-mass black holes in a super-Eddington state, little is yet established of the physics of this accretion mode. Here, we use a combined X-ray spectral and timing analysis of a…
About a hundred tidal disruption events (TDEs) have been observed and they exhibit a wide range of emission properties both at peak and over their lifetimes. Some TDEs peak predominantly at X-ray energies while others radiate chiefly at UV…
Tidal disruption events (TDEs) provide a means to probe the low end of the supermassive black hole (SMBH) mass distribution, as they are only observable below the Hills mass ($\lesssim 10^8$ M$_\odot$). Here we attempt to calibrate the…
Ultraluminous X-ray sources (ULXs) are mainly powered by accretion in neutron stars or stellar-mass black holes. Accreting at rates exceeding the Eddington limit by factors of a few up to hundreds, radiation pressure is expected to inflate…
We present new medium resolution, optical long-slit spectra of a sample of 6 UV/optical and 15 X-ray selected tidal disruption event candidate host galaxies. We measure emission line ratios from the optical spectra, finding that the large…
The flare produced when a star is tidally disrupted by a supermassive black hole holds potential as a diagnostic of both the black hole mass and the star mass. We propose a new method to realize this potential based upon a physical model of…
Gas falling quasi-spherically onto a black hole forms an inner accretion disc if its specific angular momentum $l$ exceeds $\lmin\sim r_gc$ where $r_g$ is the Schwarzschild radius. The standard disc model assumes $l\gg\lmin$. We argue that,…
We present the optical light curves of the tidal disruption event (TDE) AT 2023clx in the declining phase, observed with Mephisto. Combining our light curve with the ASAS-SN and ATLAS data in the rising phase, and fitting the composite…
A tidal disruption event (TDE) occurs when a star wanders close enough to a black hole to be disrupted by its tidal force. The debris of a tidally disrupted star are expected to form an accretion disc around the supermassive black hole. The…
Black hole impacts on accretion disks in galactic nuclei can power luminous transients, but predicting their observable signatures is challenging because the post-collision flow is highly time-dependent and inhomogeneous. We present a…
We predict late-time optical/UV emission from tidal disruption events (TDEs) from our slim accretion disc model \citep{Wen20} and explore the impact of the black hole mass $M_\bullet$, black hole spin $a_\bullet$, and accretion disc size.…