Implications for the supermassive black hole binaries from the NANOGrav 15-year data set
Abstract
Several pulsar timing array (PTA) collaborations, including NANOGrav, EPTA, PPTA, and CPTA, have announced the evidence for a stochastic signal consistent with a stochastic gravitational wave background (SGWB). Supermassive black hole binaries (SMBHBs) are supposed to be the most promising gravitational-wave (GW) sources for this signal. In this paper, we use the NANOGrav 15-year data set to constrain the parameter space in an astro-informed formation model for SMBHBs. Our results prefer a large turn-over eccentricity of the SMBHB orbit when GWs begin to dominate the SMBHB evolution. Furthermore, the SGWB spectrum is extrapolated to the space-borne GW detector frequency band by including inspiral-merge-cutoff phases of SMBHBs, indicating that the SGWB from SMBHBs should be detected by LISA, Taiji and TianQin in the near future.
- Publication:
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Science China Physics, Mechanics, and Astronomy
- Pub Date:
- December 2023
- DOI:
- 10.1007/s11433-023-2252-4
- arXiv:
- arXiv:2307.00722
- Bibcode:
- 2023SCPMA..6620402B
- Keywords:
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- Astrophysics - Cosmology and Nongalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Phenomenology
- E-Print:
- 8 pages, 3 figures, 3 tables