Velocity correction for Hubble constant measurements from standard
  sirens
  Gravitational wave (GW) sources are an excellent probe of the luminosity
distance and offer a novel measure of the Hubble constant, $H_0$. This
estimation of $H_0$ from standard sirens requires an accurate estimation of the
cosmological redshift of the host galaxy of the GW source, after correcting for
its peculiar velocity. Absence of an accurate peculiar velocity correction
affects both the precision and accuracy of the measurement of $H_0$,
particularly for nearby sources. We propose a framework to incorporate such a
peculiar velocity correction for GW sources. A first implementation of our
method to the event GW170817 combined with the Very Large Baseline
Interferometry (VLBI) observation leads to a revised value of $H_0= 68.3^{+
4.6}_{-4.5}$ km/s/Mpc. While this revision is minor, it demonstrates that our
method makes it possible for obtaining an unbiased and accurate measurements of
$H_0$ at the precision required for the standard siren cosmology.
