The NANOGrav 15-year Data Set: Constraints on Supermassive Black Hole Binaries from the Gravitational Wave Background

Abstract

The NANOGrav 15-year data set shows evidence for the presence of a low-frequency gravitational-wave background (GWB). While many physical processes can source such low-frequency gravitational waves, here we analyze the signal as coming from a population of supermassive black hole (SMBH) binaries distributed throughout the Universe. We show that astrophysically motivated models of SMBH binary populations are able to reproduce both the amplitude and shape of the observed low-frequency gravitational-wave spectrum. While multiple model variations are able to reproduce the GWB spectrum at our current measurement precision, our results highlight the importance of accurately modeling binary evolution for producing realistic GWB spectra. Additionally, while reasonable parameters are able to reproduce the 15-year observations, the implied GWB amplitude necessitates either a large number of parameters to be at the edges of expected values, or a small number of parameters to be notably different from standard expectations. While we are not yet able to definitively establish the origin of the inferred GWB signal, the consistency of the signal with astrophysical expectations offers a tantalizing prospect for confirming that SMBH binaries are able to form, reach sub-parsec separations, and eventually coalesce. As the significance grows over time, higher-order features of the GWB spectrum will definitively determine the nature of the GWB and allow for novel constraints on SMBH populations.

Accepted by Astrophysical Journal Letters as part of Focus on NANOGrav's 15-year Data Set and the Gravitational Wave Background. For questions or comments, please email [email protected]. Edited to fix two equation typos (Eq.13 & 21), and minor text typos

References in corpus (57)

• The NumPy array: a structure for efficient numerical computation
• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• The NANOGrav 15-year Data Set: Search for Signals from New Physics
• The NANOGrav 12.5-year Data Set: Search For An Isotropic Stochastic Gravitational-Wave Background
• The stochastic gravitational-wave background from massive black hole binary systems: implications for observations with Pulsar Timing Arrays
• A Compact Supermassive Binary Black Hole System
• The NANOGrav 15-year Data Set: Observations and Timing of 68 Millisecond Pulsars
• The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background
• On the evidence for a common-spectrum process in the search for the nanohertz gravitational-wave background with the Parkes Pulsar Timing Array
• The Population of Viscosity- and Gravitational Wave-Driven Supermassive Black Hole Binaries Among Luminous AGN
• Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: Inferences in the stochastic gravitational-wave background search
• Gravitational waves from resolvable massive black hole binary systems and observations with Pulsar Timing Arrays
• Supermassive black hole binaries in gaseous and stellar circumnuclear discs: orbital dynamics and gas accretion
• Bulge mass is king: The dominant role of the bulge in determining the fraction of passive galaxies in the Sloan Digital Sky Survey
• Expected properties of the first gravitational wave signal detected with pulsar timing arrays
• The Structures of Distant Galaxies I: Galaxy Structures and the Merger Rate to z~3 in the Hubble Ultra-Deep Field
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• Dynamics of triple black hole systems in hierarchically merging massive galaxies
• The Local Nanohertz Gravitational-Wave Landscape From Supermassive Black Hole Binaries
• The NANOGrav 15-Year Data Set: Detector Characterization and Noise Budget
• Self consistent model for the evolution of eccentric massive black hole binaries in stellar environments: implications for gravitational wave observations
• Hydrodynamic Torques in Circumbinary Accretion Disks
• Orbital Evolution of Equal-mass Eccentric Binaries due to a Gas Disk: Eccentric Inspirals and Circular Outspirals
• Black hole mergers from dwarf to massive galaxies with the NewHorizon and Horizon-AGN simulations
• Astrophysics Milestones For Pulsar Timing Array Gravitational Wave Detection
• A consistent measure of the merger histories of massive galaxies using close-pair statistics I: Major mergers at $z<3.5$
• Electromagnetic Counterparts to Massive Black Hole Mergers
• Long-Term Profile Variability of Double Peaked Emission Lines in Active Galactic Nuclei
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• The Effect of Orbital Eccentricity on Gravitational Wave Background Radiation from Supermassive Black Hole Binaries
• Prospects for gravitational-wave detection and supermassive black hole astrophysics with pulsar timing arrays
• Interactions between multiple supermassive black holes in galactic nuclei: a solution to the final parsec problem
• Constraining the Orbit of Supermassive Black Hole Binary 0402+379
• Massive Close Pairs Measure Rapid Galaxy Assembly in Mergers at High Redshift
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• The Search for Binary Supermassive Black Holes Amongst Quasars with Offset Broad Lines Using the Very Long Baseline Array
• Predictions for LISA and PTA based on SHARK galaxy simulations

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