With Cosmicflows-4, distances are compiled for 55,877 galaxies gathered into
38,065 groups. Eight methodologies are employed, with the largest numbers
coming from the correlations between the photometric and kinematic properties
of spiral galaxies (TF) and elliptical galaxies (FP). Supernovae that arise
from degenerate progenitors (SNIa) are an important overlapping component.
Smaller contributions come from distance estimates from the surface brightness
fluctuations of elliptical galaxies (SBF) and the luminosities and expansion
rates of core collapse supernovae (SNII). Cepheid Period-Luminosity Relation
(CPLR) and Tip of the Red Giant Branch (TRGB) observations founded on local
stellar parallax measurements along with the geometric maser distance to NGC
4258 provide the absolute scaling of distances. The assembly of galaxies into
groups is an important feature of the study in facilitating overlaps between
methodologies. Merging between multiple contributions within a methodology and
between methodologies is carried out with Bayesian Markov chain Monte Carlo
procedures. The final assembly of distances is compatible with a value of the
Hubble constant of H0=75.0 km s−1 Mpc−1 with the small statistical
error ±0.8 km s−1 Mpc−1 but a large potential systematic error
~3 km s−1 Mpc−1. Peculiar velocities can be inferred from the
measured distances. The interpretation of the field of peculiar velocities is
complex because of large errors on individual components and invites analyses
beyond the scope of this study.Comment: 38 pages, 24 figures. catalogs available at edd.ifa.hawaii.edu.
Accepted to Ap