ROSAT Discovery of Asymmetrical Cluster Gas around the Radio Galaxy NGC 326
Abstract
The Position Sensitive Proportional Counter on board ROSAT is the first X-ray detector to have made a long pointed observation of the nearby radio galaxy NGC 326. The region containing the source was imaged for 5.8 hours in soft (0.1 - 2.4 keV) X-rays as part of a program to measure the X-ray emission in low-power radio galaxies not known to be in rich clusters. Unlike other radio galaxies measured as part of this program, NGC 326 is discovered to be embedded in bright asymmetrical X-ray emitting cluster gas. There is a peak in the X-ray emission consistent with the location of the radio-galaxy core, and the gas extends a few hundred kpc from this peak (H_o = 50 km s(-1) Mpc(-1) ) even averaged over directions of least extent. The presence of large-scale X-ray emitting gas is consistent with NGC 326's membership of the Zwicky cluster 0056.9+2636. NGC 326 is known to have a `dumbbell nucleus' where two galaxies are passing at about 16 kpc projected separation (Wirth, Smarr & Gallagher 1982, AJ, 87, 602); the kinematics of the dumbbell system provides a possible explanation for the apparent change in direction over time of the twin jets of the kpc-scale radio emission. We compare radio and X-ray images to assess the influence of the gas distribution on the radio structures. Support from NASA grant NAG5-1882 & contract NAS8-39073 is gratefully acknowledged.
- Publication:
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American Astronomical Society Meeting Abstracts #184
- Pub Date:
- May 1994
- Bibcode:
- 1994AAS...184.5903W