  Conformity denotes the correlation of properties between pairs of galaxies as
a function of separation. Correlations between properties such as star
formation rate (SFR), stellar mass, and specific star formation rate (sSFR)
have implications for the impact of environment upon galaxy formation and
evolution. Conformity between primary galaxies and satellites within the same
dark matter halo has been well documented in simulations and observations.
However, the existence of conformity at greater distances - known as two-halo
conformity - remains uncertain. We investigate whether galaxies in the Local
Volume to a distance of 4 Mpc show conformity by examining SFR, sSFR, stellar
mass, and quenched fraction as a function of physical separation. Making use of
the star formation histories of these galaxies, we then extend this analysis
back in time to offer the first probe of conformity inside our past light cone.
At the present day, we find that the stellar mass or sSFR of a galaxy
correlates with the median SFR of neighboring galaxies at a separation of 2 to
3 Mpc. At a lookback time of 1 Gyr, we find a correlation with the quenched
fraction of neighboring galaxies, again at 2 to 3 Mpc separation. These signals
of conformity likely arise from the differences between the recent star
formation histories of Local Group dwarf galaxies and those outside the Local
Group. As current and future missions including JWST, Rubin, and Roman expand
the sample of Local Volume galaxies, tests of conformity using star formation
histories will provide an important tool for exploring spatio-temporal
correlations between galaxies.
