Title: Disturbed Fossil Group Galaxy NGC 1132 Author: Dong-Woo Kim, Craig Anderson, Doug Burke, Giuseppina Fabbiano, Antonella Fruscione, Jen Lauer, Michael McCollough, Doug Morgan, Amy Mossman, Ewan O'Sullivan, Alessandro Paggi, Saeqa Vrtilek, Ginevra Trinchieri
We have analysed 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 galaxy, ram pressure by external hotter gas, merger and nuclear outburst. We consider that a minor merger with a low impact parameter is the most likely origin: 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.
NGC 1132 (also UGC 2359, SDSS J025251.83-011629.1, MCG 0-8-40 and PGC 10891) is a magnitude +12.3 elliptical giant galaxy located 316 ±22 million light-years away in the constellation Eridanus.
Small dwarf galaxies surround the galaxy. NGC 1132 also lies in a huge halo of dark matter. The X-ray light from NGC 1132 extends over an area ten times greater than the length of the galaxy. NGC 1132 has a radius of 120,000 light years.
NGC 1132 was discovered by British astronomer John Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflector at Windsor Road, Slough, on the 23rd November 1827.
Right ascension02h 52m 51.81s, Declination-01° 16' 28.8"
The Hubble Space Telescope has added a new view of the giant elliptical galaxy NGC 1132, filling out our picture of a huge depository of dark matter that may have coalesced from smaller galaxies or somehow formed in isolation as a "lone wolf" in the cosmos.
The elliptical galaxy NGC 1132 reveals the final result of what may have been a group of galaxies that merged together in the recent past. Another possibility is that the galaxy formed in isolation as a "lone wolf" in a universe ablaze with galaxy groups and clusters. This image of NGC 1132 was taken with Hubble's Advanced Camera for Surveys. Data obtained in 2005 and 2006 through green and near-infrared filters were used in the composite. NGC 1132 is located approximately 318 million light-years away in the constellation Eridanus, the River.