Deep Chandra Observations of Edges and Bubbles in the NGC 5846 Galaxy
  Group
  We use a combined 120 ks Chandra exposure to analyze X-ray edges produced by
non-hydrostatic gas motions (sloshing) from galaxy collisions, and cavities
formed by AGN activity. Evidence for gas sloshing is seen in the spiral
morphology and multiple cold front edges in NGC 5846's X-ray surface brightness
distribution, while lack of spiral structure in the temperature map suggests
the perturbing interaction was not in the plane of the sky. Density and
spectral modeling across the edges indicate the relative motion of gas in the
cold fronts is at most transonic. Evidence for AGN activity is seen in two
inner bubbles at 0.6 kpc, filled with 5 GHz and 1.5 GHz radio plasma and
coincident with Halpha emission, and in a ghost bubble at 5.2 kpc west of NGC
5846's nucleus. The outburst energy and ages for the inner (ghost) bubbles are
~10^{55} ergs and ~2 Myr (~ 5 x 10^{55} ergs and 12 Myr), respectively,
implying an AGN duty cycle of 10 Myr. The inner bubble rims are threaded with 9
knots, whose total 0.5-2 keV X-ray luminosity is 0.3 x10^{40} ergs, a factor
~2-3 less than that of the surrounding rims, and 0.7 keV mean temperature is
indistinguishable from that of the rims. We suggest that the knots may be
transient clouds heated by the recent passage of a shock from the last AGN
outburst. We also observe gas stripping from a cE galaxy, NGC 5846A, in a 0.5
kpc long (~10^5 Msolar) hot gas tail, as it falls towards NGC 5846.
