Related papers: GRB060218 as a Tidal Disruption of a White Dwarf b…
We present a qualitative picture of prompt emission from tidal disruptions of white dwarfs (WD) by intermediate mass black holes (IMBH). The smaller size of an IMBH compared to a supermassive black hole and a smaller tidal radius of a WD…
The recent detection of GRB 250702B, the longest gamma-ray burst observed to date with prompt emission lasting $\sim 2.5\times 10^4$ seconds, challenges the conventional collapsar model. Its remarkable features--including an extraordinary…
There has been suggestive evidence of intermediate-mass black holes (IMBHs; 10^{3-5} M_sun) existing in some globular clusters (GCs) and dwarf galaxies, but IMBHs as a population remain elusive. As a main-sequence star passes too close by…
I suggest that the quasiperiodic ultrasoft X-ray eruptions recently observed from the galaxy GSN 069 may result from accretion from a low-mass white dwarf in a highly eccentric orbit about its central black hole. At 0.21M_sun, this star was…
GRB 250702B is a unique astrophysical transient characterised by its nature as a repeating gamma-ray trigger. Its properties include possible periodicity in its gamma-ray light curve, an X-ray counterpart that rose prior to the gamma-ray…
The progenitors of gamma-ray bursts (GRBs) have long been an unresolved issue. GRB 230307A stands out as an exceptionally bright event, belonging to the long-duration GRBs but also exhibiting a late emission component reminiscent of a…
Suggestive evidence has accumulated that intermediate mass black holes (IMBH) exist in some globular clusters. As stars diffuse in the cluster, some will inevitable wander sufficiently close to the hole that they suffer tidal disruption. An…
Intermediate-mass black holes (IMBHs) are the missing link between stellar-mass and supermassive black holes, widely believed to reside in at least some dense star clusters, but not yet observed directly. Tidal disruptions of white dwarfs…
The combination of a long duration and the absence of any accompanying supernova clearly shows that GRB 060614 can not be grouped into the two conventional classes of gamma-ray bursts, i.e. the long/soft bursts deemed to be collapsars and…
GRB$\;$250702B is the longest GRB recorded so far, with multiple gamma-ray emission episodes spread over a duration exceeding $25\;$ks and a weaker soft X-ray pre-peak $\sim1\;$day gradually rising emission. It is offset from its host…
Intermediate-mass black holes (IMBHs, $\sim 10^2-10^5M_{\odot}$) are often dubbed as the missing link between stellar mass ($\lesssim 10^2M_{\odot}$) and super-massive ($\gtrsim 10^{5-6} M_{\odot}$) BHs. Observational signatures of these…
Finding intermediate-mass black holes (IMBHs) and measuring their masses and spins are key to understanding massive black hole formation. White dwarf (WD)-IMBH binaries provide a unique probe because they emit both electromagnetic radiation…
Supermassive black holes (SMBHs) can capture and tidally disrupt stars or sub-stellar objects orbiting nearby. The detections of Sw J1644+57-like events suggest that at least some TDEs can launch a relativistic jet beaming towards Earth. A…
We present results from general relativistic calculations of the tidal disruption of white dwarf stars from near encounters with intermediate mass black holes. We follow the evolution of 0.2 and $0.6 M_\odot$ stars on parabolic trajectories…
We calculate the emission line spectrum produced by the debris released when a white dwarf (WD) is tidally disrupted by an intermediate-mass black hole (IMBH; $M\sim 10^{2}-10^{5}\msun$) and we explore the possibility of using the emission…
White dwarfs (WDs) can be tidally disrupted only by massive black holes (MBHs) with masses less than $\sim10^5 M_\odot$. These tidal interactions feed material to the MBH well above its Eddington limit, with the potential to launch a…
Eccentric white dwarf-massive black hole binaries can potentially source some extreme X-ray transients, including the recently observed quasi-periodic X-ray eruptions and tidal disruption events at the galactic nuclei. Meanwhile, they are…
The merger of binary neutron stars (NS-NS) as the progenitor of short Gamma-ray bursts (GRBs) has been confirmed by the discovery of the association of the gravitational wave (GW) event GW170817 with GRB 170817A. However, the merger product…
The transient Swift J1644+57 is believed to have been produced by an unlucky star wandering too close to a supermassive black hole (BH) leading to a tidal disruption event. This unusual flare displayed highly super-Eddington X-ray emission…
White dwarf stars that enter the tidal radius of black holes with masses $\lesssim$ $10^5$ M$_{\odot}$ are doomed to be ripped apart by tidal forces. Black holes in this mass range between stellar black holes and supermassive black holes…