Related papers: Formation pathway of Population III coalescing bin…
GW231123, the most massive binary black hole (BBH) merger detected by LIGO/Virgo/KAGRA, highlights the need to understand the origins of massive, high-spin stellar black holes (BHs). Dense star clusters provide natural environments for…
Most globular clusters (GCs) show evidence for multiple stellar populations, suggesting the occurrence of several distinct star-formation episodes. The large fraction of second population (2P) stars observed requires a very large 2P gaseous…
Aims. We present eight direct N-body simulations with NBODY6++GPU of extremely massive, initially rotating Population III star clusters with 1.01 x 10^5 stars. Methods. Our models include primordial binaries, a continuous initial mass…
Stellar mass black holes (BHs) are expected to segregate and form a steep density cusp around supermassive black holes (SMBHs) in galactic nuclei. We follow the evolution of a multi-mass system of BHs and stars by numerically integrating…
It is believed that stellar black holes (BHs) can be formed in two different ways: Either a massive star collapses directly into a BH without a supernova (SN) explosion, or an explosion occurs in a proto-neutron star, but the energy is too…
Collisions were suggested to potentially play a role in the formation of massive stars in present day clusters, and have likely been relevant during the formation of massive stars and intermediate mass black holes within the first star…
We compute the probability that intermediate mass black holes (IMBHs) capture companions due to dynamical interactions and become accreting sources, and explore the possibility that the accreting IMBHs would appear as ultra-luminous X-ray…
The recent O4a release from the LIGO-Virgo-KAGRA collaboration, which significantly increased the number of gravitational-wave (GW) detections, reveals features with potentially important astrophysical implications. One notable example is a…
In current stellar evolutionary models, the occurrence of pair instability supernovae implies the lack of stellar black holes (BHs) with masses between about $[60, \, 120] \, \rm{M}_\odot$, resulting in the presence of an upper mass gap in…
The cosmic merger rate density of black hole binaries (BHBs) can give us an essential clue to constraining the formation channels of BHBs, in light of current and forthcoming gravitational wave detections. Following a Monte Carlo approach,…
In this first of a series of papers, we utilize results for around two thousand star cluster models simulated using the MOCCA code for star cluster evolution (Survey Database I) to determine the astrophysical properties and local merger…
Mass transfer in binary systems is the key process in the formation of various classes of objects, including merging binary black holes (BBHs) and neutron stars. Orbital evolution during mass transfer depends on how much mass is accreted…
Numerical simulations have now shown that Population III (Pop III) stars can form in binaries and small clusters and that these stars can be in close proximity to each other. If so, they could be subject to binary interactions such as mass…
Recently, the LIGO-Virgo collaborations have reported the coalescence of a binary involving a black hole and a low-mass gap object (LMGO) with mass in the range $\sim2.5-5M_\odot$. Such detections, challenge our understanding of the black…
The Gaia mission and its follow-up observations have discovered a few candidates of non-interacting single black holes (BHs) and visible stars, Gaia BH1, BH2, and BH3, collectively called ``astrometric BH binaries''. This paper investigates…
We examine the relationship between individual black hole (BH) masses in merging binary black hole (BBH) systems. Analyzing the ten BBH detections from LIGO/Virgo's first two observing runs, we find that the masses of the component BHs…
We calculate cosmic distributions in space and time of the formation sites of the first, "Pop III.1" stars, exploring a model in which these are the progenitors of all supermassive black holes (SMBHs), seen in the centers of most large…
The abundance of primordial black holes (PBHs) in the mass range $0.1 - 10^3 M_\odot$ can potentially be tested by gravitational wave observations due to the large merger rate of PBH binaries formed in the early universe. To put the…
We performed population synthesis simulations of Population III binary stars with Maxwellian kick velocity distribution when MGCOs (Mass Gap Compact Objects with mass 2--5$\,M_{\odot}$) are formed. We found that for eight kick velocity…
If supermassive black holes (BHs) are generically present in galaxy centers, and if galaxies are built up through hierarchical merging, BH binaries are at least temporary features of most galactic bulges. Observations suggest, however, that…