Self-consistently heated and cooled thin circumbinary disks still drive massive black hole binaries into long-lived non-accreting phases, producing X-ray-weak, optically variable sources that LSST and Roman could find.
Gravitational Waves from Supermassive Black Hole Coalescence in a Hierarchical Galaxy Formation Model
5 Pith papers cite this work. Polarity classification is still indexing.
abstract
We investigate the expected gravitational wave emission from coalescing supermassive black hole (SMBH) binaries resulting from mergers of their host galaxies. When galaxies merge, the SMBHs in the host galaxies sink to the center of the new merged galaxy and form a binary system. We employ a semi-analytic model of galaxy and quasar formation based on the hierarchical clustering scenario to estimate the amplitude of the expected stochastic gravitational wave background owing to inspiraling SMBH binaries and bursts owing to the SMBH binary coalescence events. We find that the characteristic strain amplitude of the background radiation is $h_c(f) \sim 10^{-16} (f/1 \mu {\rm Hz})^{-2/3}$ for $f \lesssim 1 \mu {\rm Hz}$ just below the detection limit from measurements of the pulsar timing provided that SMBHs coalesce simultaneously when host galaxies merge. The main contribution to the total strain amplitude of the background radiation comes from SMBH coalescence events at $0<z<1$. We also find that a future space-based gravitational wave interferometer such as the planned \textit{Laser Interferometer Space Antenna} ({\sl LISA}) might detect intense gravitational wave bursts associated with coalescence of SMBH binaries with total mass $M_{\rm tot} < 10^7 M_{\odot}$ at $z \gtrsim 2$ at a rate $ \sim 1.0 {\rm yr}^{-1}$. Our model predicts that burst signals with a larger amplitude $h_{\rm burst} \sim 10^{-15}$ correspond to coalescence events of massive SMBH binary with total mass $M_{\rm tot} \sim 10^8 M_{\odot}$ at low redshift $ z \lesssim 1$ at a rate $ \sim 0.1 {\rm yr}^{-1}$ whereas those with a smaller amplitude $h_{\rm burst} \sim 10^{-17}$ correspond to coalescence events of less massive SMBH binary with total mass $M_{\rm tot} \sim 10^6 M_{\odot}$ at high redshift $ z \gtrsim 3$.
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Pulsar timing arrays can probe supermassive black hole binaries that merged prior to observations via the pulsar term, with SKA potentially detecting a few such zombie binaries at SNR > 3.
A hierarchical Bayesian inference framework combining free-spectrum reconstruction with population-level likelihoods distinguishes finite SMBHB populations from Gaussian primordial GWB using mock PTA data.
FABLE simulation predictions for the nanohertz gravitational wave background are statistically consistent with NANOGrav 15-year data at 1–2.5σ tension, with physically motivated population modifications further improving agreement.
Spectroscopic analysis of dual nuclei shows SMBH masses higher in galaxy mergers than single nuclei at fixed stellar mass.
citing papers explorer
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Dynamics and detectability of long-lived non-accretion phases for massive black hole binaries in cold, thermally regulating disks
Self-consistently heated and cooled thin circumbinary disks still drive massive black hole binaries into long-lived non-accreting phases, producing X-ray-weak, optically variable sources that LSST and Roman could find.
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Probing Supermassive Black Hole Mergers with Pulsar Timing Arrays
Pulsar timing arrays can probe supermassive black hole binaries that merged prior to observations via the pulsar term, with SKA potentially detecting a few such zombie binaries at SNR > 3.
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Population statistics of nanohertz gravitational wave sources
A hierarchical Bayesian inference framework combining free-spectrum reconstruction with population-level likelihoods distinguishes finite SMBHB populations from Gaussian primordial GWB using mock PTA data.
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Comparing gravitational wave background predictions from cosmological simulations to pulsar timing observations
FABLE simulation predictions for the nanohertz gravitational wave background are statistically consistent with NANOGrav 15-year data at 1–2.5σ tension, with physically motivated population modifications further improving agreement.
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Investigating the Spectral Properties of Dual Nuclei in Galaxy Mergers from the GOTHIC survey: Supermassive Black Hole Growth, metal enrichment and Dual AGN
Spectroscopic analysis of dual nuclei shows SMBH masses higher in galaxy mergers than single nuclei at fixed stellar mass.