Related papers: Minding the gap: GW190521 as a straddling binary
The source binary of the gravitational-wave (GW) event GW230529, detected at the beginning of the fourth LIGO-Virgo-KAGRA observing run, was inferred to consist of a NS and a compact object in the lower mass gap, a purported gap between the…
The detection of GW190521 by the LIGO-Virgo collaboration has revealed the existence of black holes (BHs) in the pair-instability (PI) mass gap. Here, we investigate the formation of BHs in the PI mass gap via star -- star collisions in…
Two of the dominant channels to produce the black-hole binary mergers observed by LIGO and Virgo are believed to be the isolated evolution of stellar binaries in the field and dynamical formation in star clusters. Their relative efficiency…
We perform a search for binary black hole mergers with one subsolar mass black hole and a primary component above $2 M_\odot$ in the second observing run of LIGO/Virgo. Our analysis therefore extends previous searches into a mass region…
We address two important questions in gravitational-wave astronomy. What is the astrophysical formation scenario leading to black-hole binary mergers? Did some of the merging black holes form hierarchically through previous generations of…
The LIGO/Virgo gravitational--wave observatories have detected 50 BH-BH coalescences. This sample is large enough to have allowed several recent studies to draw conclusions about the branching ratios between isolated binaries versus dense…
Stellar evolution theory predicts a "gap" in the black hole birth function caused by the pair instability. Presupernova stars that have a core mass below some limiting value, Mlo, after all pulsational activity is finished, collapse to…
The discovery of gravitational wave radiation from merging black holes (BHs) also uncovered BHs with masses in the range of ~20-160 Msun. In contrast, the most massive Galactic stellar-mass BH currently known has a mass ~21 Msun. While…
GW190426_152155 was recently reported as one of the 39 candidate gravitational wave (GW) events in \citet{2020arXiv201014527A}, which has an unusual source-frame chirp mass $\sim 2.4M_{\odot}$ and may be the first GW signal from a neutron…
We investigate the evolution of supermassive binary black holes (BBHs) in galaxies with realistic property distributions and the gravitational-wave (GW) radiation from the cosmic population of these BBHs. We incorporate a comprehensive…
We report the observation of gravitational waves from a binary-black-hole coalescence during the first two weeks of LIGO's and Virgo's third observing run. The signal was recorded on April 12, 2019 at 05:30:44 UTC with a network…
Simultaneous measurements of distance and redshift can be used to constrain the expansion history of the universe and associated cosmological parameters. Merging binary black hole (BBH) systems are standard sirens---their gravitational…
The intermediate mass black hole range, $10\lesssim M_{\rm BH}^{}/M_\odot^{}\lesssim 10^{5} $, has long offered enticing possibilities for primordial black holes (PBH), with populations in this range postulated to be responsible for some of…
The astrophysical origin of binary black hole (BBH) mergers remains uncertain, although many events have been observed by the LIGO-Virgo-KAGRA network. Such mergers are potentially originated in the vicinity of massive black holes (MBHs).…
We analyse the apparent disagreement between the mass estimates of the central black hole(s) in Mkn~501 based on (i) the observations of the host galaxy, (ii) the high energy (HE) emission mechanism, and (iii) the modulation of the beamed…
Gravitational-wave observations of massive, rapidly spinning binary black holes mergers provide increasing evidence for the dynamical origin of some mergers. Previous studies have interpreted the mergers with primary mass…
Gravitational waves (GWs) offer an unprecedented opportunity to survey the sky and detect mergers of compact objects. While intermediate-mass black holes (IMBHs) have not been detected beyond any reasonable doubt with either dynamical or…
We model the formation and retention of the most massive black hole (BH) in 47~Tuc using the semi-analytical code \texttt{cBHBd}, coupling cluster evolution with binary BH dynamics and computing merger-remnant masses, spins, and…
The detection of the gravitational wave event GW230529, presumably a neutron star-black hole (NSBH) merger, by the LIGO-Virgo-KAGRA (LVK) Collaboration marks an exciting discovery for multimessenger astronomy. The black hole (BH) has a high…
The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses $\gtrsim 30\, \text{M}_\odot$, suggests a population of binary black holes with relatively high mass. This…