Related papers: The Black Hole Candidate LSI+61303

We report on six Chandra and one HST/WFC3 observation of CXO J122518.6+144545, discovered by Jonker et al. (2010) as a candidate hyperluminous X-ray source (HLX), X-ray bright supernova or recoiling supermassive black hole at $L_X = 2.2…

Recently, the gravitational-wave (GW) event S241125n, detected by LIGO/Virgo/KAGRA (LVK), has been reported to coincide with a candidate detected by Swift-BAT/GUANO and an X-ray candidate found by FXT onboard of Einstein Probe (EP) and…

We report the results from the broad-band X-ray monitoring of the new Galactic black hole candidate MAXI J1803$-$298 with the MAXI/GSC and Swift/BAT during its outburst. After the discovery on 2021 May 1, the soft X-ray flux below 10 keV…

Stellar-mass black holes have all been discovered through X-ray emission, which arises from the accretion of gas from their binary companions (this gas is either stripped from low-mass stars or supplied as winds from massive ones). Binary…

We present the first results on the new black hole candidate, MAXI J1305-704, observed by MAXI/GSC. The new X-ray transient, named as MAXI J1305-704, was first detected by the MAXI-GSC all-sky survey on 2012 April 9 in the direction to the…

The origin and distribution of stellar-mass black hole spins are a rare window into the progenitor stars and supernova events that create them. Swift J1728.9-3613 is an X-ray binary, likely associated with the supernova remnant G351.9-0.9…

X-ray flares have been discovered in black hole systems, such as gamma-ray bursts, the tidal disruption event Swift J1644+57, the supermassive black hole Sagittarius A$^*$ at the center of our Galaxy, and some active galactic nuclei. Their…

We search for nearby, isolated, accreting, ``stellar-mass'' (3 to $100M_\odot$) black holes. Models suggest a synchrotron spectrum in visible wavelengths and some emission in X-ray wavelengths. Of 3.7 million objects in the Sloan Digital…

We present a systematic X-ray study, the third in a series, of 49 active galactic nuclei with intermediate-mass black holes (IMBH; ~10^5-10^6 M_sun) using Chandra observations. We detect 42 out of 49 targets with a 0.5-2 keV X-ray…

The observations and theory of the exciting new class of galactic black hole X-ray transients is reviewed. Seven of these systems have measured mass functions or mass estimates in excess of stable neutron stars, making them excellent black…

Ultralight dark photons predicted in several Standard Model extensions can trigger the superradiant instability around rotating black holes if their Compton wavelength is comparable to the Blackhole radius. Consequently, the angular…

We report spectral analysis of the persistent black hole X-ray binary, 4U 1957+115, using AstroSat, Swift and NuSTAR observations carried out between 2016-2019. Modelling with a disk emission, thermal comptonization and blurred reflection…

Through the years numerous attempts have been made to connect the phenomenology and physics of mass accretion onto stellar-mass and super-massive black holes in a scale-invariant fashion. In this paper, we explore this connection at the…

We present the results of a joint Swift-NuSTAR spectroscopy campaign on M31. We focus on the five brightest globular cluster X-ray sources in our fields. Two of these had previously been argued to be black hole candidates on the basis of…

We study the formation of low-mass X-ray binaries with a black hole as accreting object. The performed semi-analytic analysis reveals that the formation rate of black holes in low-mass X-ray binaries is about two orders of magnitude smaller…

We present quasi-simultaneous radio and X-ray observations of the black hole X-ray binary GRS 1739--278 of its 2015-2016 mini-outbursts, i.e. between 2015 June 10 and 2016 October 31, with the X-ray-to-radio time interval being less than…

For a successful detection of gravitational waves by LISA, it is essential to construct theoretical waveforms in a reliable manner. We discuss gravitational waves from an extreme mass ratio binary system which is expected to be a promising…

We present a comprehensive broadband spectral and variability study of the newly detected black hole X-ray binary Swift~J1727.8--1613 in the intermediate states during its 2023 outburst, using multi-mission observations from NICER, NuSTAR,…

The first detection of an optical counterpart to a gravitational wave signal revealed that collaborative efforts between instruments with different specializations provide a unique opportunity to acquire impactful multi-messenger data. We…

The optical light curves of quiescent black hole low-mass X-ray binaries often exhibit significant non-ellipsoidal variabilities, showing the photospheric radiation of the companion star is veiled by other source of optical emission.…