2023ApJ...943...56P

We present a new constraint on the Hubble constant H₀ using a sample of well-localized gravitational-wave (GW) events detected during the first three LIGO/Virgo observing runs as dark standard sirens. In the case of dark standard sirens, a unique host galaxy is not identified, and the redshift information comes from the distribution of potential host galaxies. From the third LIGO/Virgo observing run detections, we add the asymmetric-mass binary black hole GW190412 and the high-confidence GW candidates S191204r, S200129m, and S200311bg to the sample of dark standard sirens analyzed in Palmese et al. Our sample contains the top 20% (based on localization) GW events and candidates to date with significant coverage by the Dark Energy Spectroscopic Instrument Legacy Survey. We combine the H₀ posterior for eight dark siren events, finding ${H}_{0}={79.8}_{-12.8}^{+19.1}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ (68% highest density interval) for a prior in H₀ uniform between [20, 140] km s^–1 Mpc^–1. This result shows that a combination of eight well-localized dark sirens combined with an appropriate galaxy catalog is able to provide an H₀ constraint that is competitive (∼20% versus 18% precision) with a single bright standard siren analysis (i.e., assuming the electromagnetic counterpart) using GW170817. When combining the posterior with that from GW170817, we obtain ${H}_{0}={72.77}_{-7.55}^{+11.0}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$. This result is broadly consistent with recent H₀ estimates from both the cosmic microwave background and supernovae.