The environments of the radio galaxy population in SIMBA
  We investigate the environmental properties of the radio galaxy population
using the Simba cosmological hydrodynamic simulation. We identify centrals and
satellites from a population of high and low excitation radio galaxies (HERGs
and LERGs) in Simba, and study their global properties. We find that $\sim
20\%$ of radio galaxies are satellites and that there are insignificant
differences in the global properties of LERGs based on its central/satellite
classification. Satellite HERGs display lower values of star formation, 1.4GHz
radio luminosity, and Eddington fraction. We further investigate the
environments of radio galaxies and show that HERGs typically live in underdense
environments, similar to star-forming galaxies. The environments of high-mass
LERGs are similar to non-radio galaxies, but low-mass LERGs live in underdense
environments similar to HERGs. At all black hole masses, LERGs live in
environments similar to that of quenched and normal galaxies while HERGs live
in environments similar to that of star-forming galaxies. The richness of a
LERGs environment decreases with increasing Eddington fraction, and the
environments of all radio galaxies do not depend on radio luminosity for
$P_{1.4GHz}$ < $10^{24}$ W Hz$^{-1}$. Complementing these results, we find that
LERGs cluster on the same scale as the total galaxy population while HERGs are
unlikely to be found within the same dark matter halo. Finally, we show that
there is no environmental preference for radio galaxies at $z=2$. Simba
predicts that with more sensitive surveys, we will find populations of radio
galaxies in environments much similar to the total galaxy population.
