A Quasar-based Supermassive Black Hole Binary Population Model: Implications for the Gravitational Wave Background

  title={A Quasar-based Supermassive Black Hole Binary Population Model: Implications for the Gravitational Wave Background},
  author={J. Andrew Casey-Clyde and Chiara M. F. Mingarelli and Jenny E. Greene and Kris Pardo and Morgan Na{\~n}ez and Andy D. Goulding},
  journal={The Astrophysical Journal},
The nanohertz gravitational wave background (GWB) is believed to be dominated by GW emission from supermassive black hole binaries (SMBHBs). Observations of several dual-active galactic nuclei (AGN) strongly suggest a link between AGN and SMBHBs, given that these dual-AGN systems will eventually form bound binary pairs. Here we develop an exploratory SMBHB population model based on empirically constrained quasar populations, allowing us to decompose the GWB amplitude into an underlying… 

Consistency of the Parkes Pulsar Timing Array Signal with a Nanohertz Gravitational-wave Background

Pulsar timing array experiments have recently reported strong evidence for a common-spectrum stochastic process with a strain spectral index consistent with that expected of a nanohertz-frequency



Systematic investigation of the expected gravitational wave signal from supermassive black hole binaries in the pulsar timing band

In this letter we carry out the first systematic investigatio n of the expected gravitational wave (GW) background generated by supermassive black hole (SMBH) binaries in the nHz frequency band

Discovery of a Close-separation Binary Quasar at the Heart of a z ∼ 0.2 Merging Galaxy and Its Implications for Low-frequency Gravitational Waves

Supermassive black hole (SMBH) binaries with masses of ∼108–109M⊙ are expected to dominate the contribution to the as-yet undetected gravitational wave background (GWB) signal at the nanohertz

Pulsar timing constraints on the Fermi massive black hole binary blazar population

Blazars are a sub-population of quasars whose jets are nearly aligned with the line-of-sight, which tend to exhibit multi-wavelength variability on a variety of timescales. Quasi-periodic variability

Constraining astrophysical observables of galaxy and supermassive black hole binary mergers using pulsar timing arrays

We present an analytic model to describe the supermassive black hole binary (SMBHB) merger rate in the Universe with astrophysical observables: galaxy stellar mass function, pair fraction, merger

Local supermassive black holes, relics of active galactic nuclei and the X-ray background

We quantify the importance of mass accretion during AGN phases in the growth of supermassive black holes (BH) by comparing the mass function of black holes in the local universe with that expected

A hidden population of high-redshift double quasars unveiled by astrometry

Galaxy mergers occur frequently in the early Universe1 and bring multiple supermassive black holes (SMBHs) into the nucleus, where they may eventually coalesce. Identifying post-merger-scale (that

A Unified, Merger-driven Model of the Origin of Starbursts, Quasars, the Cosmic X-Ray Background, Supermassive Black Holes, and Galaxy Spheroids

We present an evolutionary model for starbursts, quasars, and spheroidal galaxies in which mergers between gas-rich galaxies drive nuclear inflows of gas, producing starbursts and feeding the buried

Low-Frequency Gravitational Radiation from Coalescing Massive Black Hole Binaries in Hierarchical Cosmologies

We compute the expected low-frequency gravitational wave signal from coalescing massive black hole (MBH) binaries at the center of galaxies in a hierarchical structure formation scenario in which

Inward Bound—The Search for Supermassive Black Holes in Galactic Nuclei

Dynamical searches reveal central dark objects with masses"" 106 to 109.5 M0 in the Galaxy, M31, M32, M87, NGC 3115, NGC 3377, NGC 4258, and NGC 4594. Indirect arguments suggest but do not prove that

The stochastic gravitational-wave background from massive black hole binary systems: implications for observations with Pulsar Timing Arrays

Massive black hole binary systems, with masses in the range � 10 4 10 10 M⊙, are among the primary sources of gravitational waves in the frequency window � 10 −9 Hz 0.1Hz. Pulsar Timing Arrays (PTAs)