摘要
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 Tian Qin in the near future.
基金
supported by the National Natural Science Foundation of China(Grant Nos.12250010,11975019,11991052,and 12047503)
the Key Research Program of Frontier Sciences,CAS(Grant No.ZDBS-LY-7009)
the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-006)
the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB15)
supported by the National Natural Science Foundation of China(Grant Nos.12247176,and 12247112)
the China Postdoctoral Science Foundation Fellowship(Grant No.2022M710429)。
