Disturbed Fossil Group Galaxy NGC 1132
  We have analyzed the Chandra archival data of NGC 1132, a well-known fossil
group, i.e. a system expected to be old and relaxed long after the giant
elliptical galaxy assembly. Instead, the Chandra data reveal that the hot gas
morphology is disturbed and asymmetrical, with a cold front following a
possible bow shock. We discuss possible origins of the disturbed hot halo,
including sloshing by a nearby object, merger, ram pressure by external hotter
gas and nuclear outburst. We consider that the first two mechanisms are likely
explanations for the disturbed hot halo, with a slight preference for a minor
merger with a low impact parameter because of the match with simulations and
previous optical observations. In this case, NGC 1132 may be a rare example of
unusual late mergers seen in recent simulations. Regardless of the origin of
the disturbed hot halo, the paradigm of the fossil system needs to be
reconsidered.
