Related papers: Astrophysical constraints on massive black hole bi…
Recent Pulsar Timing Arrays (PTAs) results provided strong evidence for a stochastic gravitational wave background (sGWB), consistent with a population of merging massive black holes (MBHs) at $z<1$. Meanwhile, JWST observations at $z>5$…
Gravitational wave detectors are observing an increasing number of binary black hole (BBH) mergers, revealing a bimodal mass distribution of BBHs, which hints at diverse formation histories for these systems. Using the rapid binary…
The population of black holes observed via gravitational waves currently covers the local universe up to a redshift $z\lesssim 1$, for the most massive merging binaries, or $z\lesssim 0.25$ for low-mass BH binaries (BBH). Evolution of the…
The possible existence of primordial black holes in the stellar mass window has received considerable attention because their mergers may contribute to current and future gravitational-wave detections. Primordial black hole mergers,…
The advent of next generation radio telescope facilities, such as the Square Kilometer Array (SKA), will usher in an era where a Pulsar Timing Array (PTA) based search for gravitational waves (GWs) will be able to use hundreds of well timed…
The redshift evolution of the binary black hole (BBH) merger rate can be expressed as the convolution of the progenitor formation rate with the distribution of time delays between formation and merger. We show that starting with data-driven…
The observation of massive black hole binaries (MBHBs) with Pulsar Timing Arrays (PTAs) is one of the goals of gravitational wave astronomy in the coming years. Massive (>10^8 solar masses) and low-redshift (< 1.5) sources are expected to…
In this paper, the second in a series of two, we justify two important assumptions on which the result is based that in course of a galaxy merger the slingshot ejection of bound stars is sufficiently efficient to allow a supermassive black…
NANOGrav and other Pulsar Timing Arrays (PTAs) have discovered a common-spectrum process in the nHz range that may be due to gravitational waves (GWs): if so, they are likely to have been generated by black hole (BH) binaries with total…
At low redshift, massive black holes are found in the centers of almost all large elliptical galaxies, and also in many lower-mass systems. Their evolution is believed to be inextricably entangled with that of their host galaxies. On the…
Pulsar timing arrays (PTAs) are anticipated to detect the stochastic gravitational wave background (GWB) from supermassive binary black holes (BBHs) as well as the gravitational waves from individual BBHs. Recently, a common process signal…
We present results on the mass, spin, and redshift distributions with phenomenological population models using the ten binary black hole mergers detected in the first and second observing runs completed by Advanced LIGO and Advanced Virgo.…
Supermassive black holes are commonly found in the center of galaxies and evolve with their hosts. The supermassive binary black holes (SMBBH) are thus expected to exist in close galaxy pairs, however, none has been unequivocally detected.…
Numerous observations have shown that almost all galaxies in our Universe host supermassive black holes (SMBHs), but there is still much debate about their formation and evolutionary processes. Recently, gravitational waves (GWs) have been…
The growing evidence of supermassive black holes (SMBHs) being present in the early Universe poses challenges to their traditional formation pathways. Separately, studies suggest that merging SMBH binaries with total masses $\gtrsim 10^9…
Galaxy mergers at high redshifts trigger the activity of their central supermassive black holes, eventually also leading to their coalescence -- and a potential source of low-frequency gravitational waves detectable by the SKA Pulsar Timing…
The mergers of galaxies and supermassive black holes (SMBHs) are key drivers of galaxy evolution, contributing to the growth of both galaxies and their central black holes. Current and upcoming gravitational wave (GW) detectors -- Pulsar…
Massive black holes (MBHs) exist in the Galactic center (GC) and other nearby galactic nuclei. As natural outcome of galaxy mergers, some MBHs may have a black hole (BH) companion. In this paper, assuming that the MBHs in the GC and some…
Pulsar timing arrays (PTAs) measure nHz frequency gravitational waves (GWs) generated by orbiting massive black hole binaries (MBHBs) with periods between 0.1-10 yr. Previous studies on the nHz GW background assumed that the inspiral is…
The coalescence of massive black hole binaries (with masses $10^4 - 10^7 M_{\odot}$) leads to gravitational wave emission that is detectable out to high redshifts ($z \sim 20$) with the forthcoming LISA observatory. We combine the…