The Impact of the Group Environment on the OVI Circumgalactic Medium
  We present a study comparing OVI $\lambda\lambda$1031, 1037 doublet
absorption found towards group galaxy environments with that of isolated
galaxies. The OVI absorption in the circumgalactic medium (CGM) of isolated
galaxies has been studied previously by the "Multiphase Galaxy Halos" survey,
where the kinematics and absorption properties of the CGM have been
investigated. We extend these studies to group environments. We define a galaxy
group to have two or more galaxies having a line-of-sight velocity difference
of no more than 1000 km/s and located within 350 kpc (projected) of a
background quasar sightline. We identified a total of six galaxy groups
associated with OVI absorption $W_{\rm r}>0.06$ {\AA} that have a median
redshift of $\langle z_{\rm gal} \rangle = 0.1669$ and a median impact
parameter of $\langle D \rangle = 134.1$ kpc. An additional 12 non-absorbing
groups were identified with a median redshift of $\langle z_{\rm gal} \rangle =
0.2690$ and a median impact parameter of $\langle D \rangle = 274.0$ kpc. We
find the average equivalent width to be smaller for group galaxies than for
isolated galaxies $(3\sigma)$. However, the covering fractions are consistent
with both samples. We used the pixel-velocity two-point correlation function
method and find that the velocity spread of OVI in the CGM of group galaxies is
significantly narrower than that of isolated galaxies $(10\sigma)$. We suggest
that the warm/hot CGM does not exist as a superposition of halos, instead, the
virial temperature of the halo is hot enough for OVI to be further ionised. The
remaining OVI likely exists at the interface between hot, diffuse gas and
cooler regions of the CGM.
