THE X-RAY ENVIRONMENT OF THE DUMBBELL RADIO GALAXY NGC-326

Citation
Dm. Worrall et al., THE X-RAY ENVIRONMENT OF THE DUMBBELL RADIO GALAXY NGC-326, The Astrophysical journal, 449(1), 1995, pp. 93-104
Citations number
40
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
0004637X
Volume
449
Issue
1
Year of publication
1995
Part
1
Pages
93 - 104
Database
ISI
SICI code
0004-637X(1995)449:1<93:TXEOTD>2.0.ZU;2-8
Abstract
We report the first detailed X-ray observations of the dumbbell radio galaxy NGC 326. The region containing the source was imaged for 5.8 hr in soft X-rays with the ROSAT PSPC as part of a program to measure th e X-ray emission in low-power radio galaxies not known to be in rich c lusters. Unlike other radio galaxies measured as part of this program, NGC 326 is discovered to be embedded in bright asymmetrical X-ray-emi tting cluster gas of temperature kT similar to 2 keV and 0.1-2.4 keV l uminosity 3.5 x 10(36) W (H-0 = 50 km s(-1) Mpc(-1)). There is a peak in the X-ray emission consistent with the location of the radio galaxy core. Five of the 10 brightest galaxies in the region are the brighte st optical objects in error circles of excess X-ray emission. In the s ame observation, ROSAT also detected the unrelated, more distant, clus ter Abell 115 and provided its first spectral measurement: kT = 7.2(-1 .9)(+9) keV. It has been suggested previously that galaxy kinematics a re responsible for the apparent change in direction over time of the t win jets of the large-scale radio emission of NGC 326. This was though t to be due either to a misalignnent between the radio beam and galaxy axes or to interaction between the two galaxies which form the dumbel l nucleus of NGC 326 and which are known to be passing at about 16 kpc projected separation. Our X-ray results support a different explanati on: that buoyancy forces have bent the outer radio structure.