Chandra Observation of 3C288 - Reheating the Cool Core of a 3 keV
  Cluster from a Nuclear Outburst at z = 0.246
  We present results from a 42 ks Chandra/ACIS-S observation of the
transitional FRI/FRII radio galaxy 3C288 at z = 0.246. We detect $\sim$3 keV
gas extending to a radius of $\sim$0.5 Mpc with a 0.5-2.0 keV luminosity of 6.6
$\times$ 10$^{43}$ ergs s$^{-1}$, implying that 3C288 lies at the center of a
poor cluster. We find multiple surface brightness discontinuities in the gas
indicative of either a shock driven by the inflation of the radio lobes or a
recent merger event. The temperature across the discontinuities is roughly
constant with no signature of a cool core, thus disfavoring either the merger
cold-front or sloshing scenarios. We argue therefore that the discontinuities
are shocks due to the supersonic inflation of the radio lobes. If they are
shocks, the energy of the outburst is $\sim$10^{60} ergs, or roughly 30% of the
thermal energy of the gas within the radius of the shock, assuming that the
shocks are part of a front produced by a single outburst. The cooling time of
the gas is $\sim$10^8 yrs, so that the energy deposited by the nuclear outburst
could have reheated and efficiently disrupted a cool core.
