The SLUGGS Survey: revisiting the correlation between X-ray luminosity
  and total mass of massive early-type galaxies
  Here we utilise recent measures of galaxy total dynamical mass and X-ray gas
luminosities (L$_{X,Gas}$) for a sample of 29 massive early-type galaxies from
the SLUGGS survey to probe L$_{X,Gas}$--mass scaling relations. In particular,
we investigate scalings with stellar mass, dynamical mass within 5 effective
radii (R$_e$) and total virial mass. We also compare these relations with
predictions from $\Lambda$CDM simulations. We find a strong linear relationship
between L$_{X,Gas}$ and galaxy dynamical mass within 5 R$_e$, which is
consistent with the recent cosmological simulations of Choi et al. that
incorporate mechanical heating from AGN. We conclude that the gas surrounding
massive early-type galaxies was shock heated as it fell into collapsing dark
matter halos so that L$_{X,Gas}$ is primarily driven by the depth of a galaxy's
potential well. Heating by an AGN plays an important secondary role in
determining L$_{X,Gas}$.
