A Measurement of the Hubble Constant using Gravitational Waves from the Binary Merger GW190814
Abstract
We present a test of the statistical method introduced by Bernard F. Shutz in 1986 using only gravitational waves to infer the Hubble constant ($\text{H}_0$) from GW190814, the first highprobability neutronstarblackhole (NSBH) merger candidate detected by the Laser Interferometer Gravitationalwave Observatory (LIGO) and the Virgo interferometer. We apply a baseline test of this method to the binary neutron star (BNS) merger GW170817 and find $\text{H}_0 = 70^{+35.0}_{18.0}$km s$^{1}$ Mpc$^{1}$ (maximum {\it a posteriori} and 68.3\% highest density posterior interval) for a galaxy $B$band luminosity threshold of $L_B \geq 0.001 L_B^*$ with a correction for catalog incompleteness. Repeating the calculation for GW190814, we obtain $\text{H}_0 = 67^{+41.0}_{26.0}$ km s$^{1}$ Mpc$^{1}$ and $\text{H}_0 = 71^{+34.0}_{30.0}$ km s$^{1}$ Mpc$^{1}$ for $L_B \geq 0.001 L_B^*$ and $L_B \geq 0.626 L_B^*$, respectively. Combining the posteriors for both events yields $\text{H}_0 = 70^{+29.0}_{18.0}$ km s$^{1}$ Mpc$^{1}$, demonstrating the improvement on constraints when using multiple gravitationalwave events. We also confirm the results of other works that adopt this method, showing that increasing the $L_B$ threshold enhances the posterior structure and slightly shifts the distribution's peak to higher $\text{H}_0$ values. We repeat the joint inference using the lowspin PhenomPNRT (Abbott et al. 2019a) and the newly available combined (SEOBNRv4PHM + IMRPhenomPv3HM; Abbott et al. 2020) posterior samples for GW170817 and GW190814, respectively, achieving a tighter constraint of $\text{H}_0 = 69^{+29.0}_{14.0}$ km s$^{1}$ Mpc$^{1}$.
 Publication:

arXiv eprints
 Pub Date:
 July 2020
 arXiv:
 arXiv:2007.11148
 Bibcode:
 2020arXiv200711148V
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 (Received: 04/28/2020, Accepted: 09/06/2020)