Revisiting the X-ray - Mass scaling relations of Early-type Galaxies
  with the Mass of their Globular Cluster Systems as a Proxy for the Total
  Galaxy Mass
  Using globular cluster (GC) kinematics and photometry data, we calibrate the
scaling relation between the total galaxy mass (M_TOT including dark matter)
and total globular cluster system mass (M_GCS) in a sample of 30 early-type
galaxies (ETG), confirming a nearly linear relationship between the two
physical parameters. Using samples of 83 and 57 ETGs, we investigate this
scaling relation in conjunction with the previously known relations between
M_TOT and the ISM X-ray luminosity and temperature, respectively. We confirm
that M_GCS can be effectively used as a proxy of M_TOT. We further find that
the L_X,GAS - M_TOT relation is far tighter in the subsample of core ETGs, when
compared to cusp ETGs. In core ETGs (old, passively evolving stellar systems)
M_TOT is significantly larger than the total stellar mass M_STAR and the
correlation with the hot gas properties is driven by their dark matter mass
M_DM. Cusp ETGs have typically lower LX,GAS than core ETGs. In cusp ETGs, for a
given M_DM, higher L_X,GAS is associated with higher M_STAR, suggesting stellar
feedback as an important secondary factor for heating the ISM. Using the M_GCS-
M_TOT scaling relations we compare 272 ETGs with previous estimates of the
stellar-to-halo mass relation of galaxies. Our model-independent estimate of
M_TOT results in a good agreement around halo masses of 10^12 Mo, but suggest
higher star formation efficiency than usually assumed both at the low and at
the high halo mass ends.
