Disturbed Fossil Group Galaxy NGC 1132

Journal
Date Issued
2018
Author(s)
Kim, Dong-Woo
•
Anderson, Craig
•
Burke, Doug
•
Fabbiano, Giuseppina
•
•
Lauer, Jen
•
McCollough, Michael
•
Morgan, Doug
•
Mossman, Amy
•
O’Sullivan, Ewan
•
•
Vrtilek, Saeqa
•
DOI
Abstract
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.
Volume
853
Issue
2
Start page
129
Uri
Url
Issn Identifier
0004-637X
Ads BibCode
2018ApJ...853..129K
Rights
open.access
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