Capability for detection of GW190521-like binary black holes with\n TianQin

Abstract

The detection of GW190521 gains huge attention because it is the most massive\nbinary that LIGO and Virgo ever confidently detected until the release of\nGWTC-3 (GW190426_190642 is more massive), and it is the first black hole merger\nwhose remnant is believed to be an intermediate mass black hole. Furthermore,\nthe primary black hole mass falls in the black hole mass gap, where the\npair-instability supernova prevents the formation of astrophysical black holes\nin this range. In this paper, we systematically explore the prospect of TianQin\non detecting GW190521-like sources. For sources with small orbital\neccentricities, (i) TianQin could resolve up to a dozen of sources with\nsignal-to-noise ratio (SNR) larger than 8. Even if the signal-to-noise ratio\nthreshold increases to 12, TianQin could still detect GW190521-like binaries.\n(ii) The parameters of sources merging within several years would be precisely\nrecovered. The precision of coalescence time and sky localization closes to $1\\\n{\\rm s}$ and $1\\ {\\rm deg^{2}}$ respectively. This indicates that TianQin could\nprovide early warnings for ground-based gravitational waves detectors and\nelectromagnetic telescopes for these sources. Furthermore, TianQin could\ndistinguish the formation channels of these sources by measuring the orbital\neccentricities with a relative precision of $10^{-4}$. (iii) TianQin could\nconstrain the Hubble constant with a $10\\%$ precision with GW190521-like\nsources. Finally, for very eccentric GW190521-like sources, although their\ngravitational wave signal might be too weak for TianQin to detect, even the\nnull detection of TianQin could still present a significant contribution to the\nunderstanding of the underlying science.\n