Effects of baryons on the gravitational redshift profile of {\Lambda}CDM
  halos
  Gravitational redshifts and other relativistic effects are beginning to be
studied in the context of galaxy clustering. Distortions consistent with those
expected in General Relativity have been measured in galaxy cluster redshift
profiles by Wojtak et al. and others and in the the cross-correlation function
of galaxy populations by Alam et al. On scales below ~20 Mpc/$h$ simulations
have shown that gravitational redshift dominates over other effects. However,
this signal is related to the shape and depth of gravitational potentials, and
therefore the matter density in galaxies and galaxy clusters that is
responsible for them. We investigate the effects of baryonic physics on the
gravitational redshift profiles of massive (group and cluster-sized) halos. We
compare the profiles of different components in halos taken from the
MassiveBlack-II cosmological hydrodynamic simulation and a dark matter-only
version of the same simulation. We find that inclusion of baryons, cooling,
star formation and feedback significantly alters the relevant inner density
profiles. These baryonic effects lead to overall increases in both
gravitational redshifts and the transverse relativistic Doppler effects by up
to ~50% for group size halos. We show how modified Navarro Frenk White halo
profiles can be used to parametrize these differences, and provide relevant
halo profile fits.
