Deep ROSAT HRI Observations of the NGC 1399/NGC 1404 Region: Morphology and Structure of the X-Ray Halo

摘要: We present the analysis of a deep (167 ks) ROSAT HRI observation cD galaxy NGC 1399 in Fornax Cluster, comparing it with previous work on this and recent Chandra data. find, agreement observations, an extended asymmetric gaseous halo luminosity (in 0.1-2.4 keV energy band) LX = (5.50 ± 0.04) × 1041 ergs s-1 within 46 kpc (assuming distance D 19 Mpc). Using both and, at larger radii, archival PSPC data, we find that radial behavior X-ray surface brightness profile is not consistent simple β-model suggests instead three distinct components. use multicomponent bidimensional model to study detail these components, which identify respectively cooling flow region, galactic halo, cluster halo. From data derive binding mass distribution suggested by optical dynamical indicators, inner core dominated luminous matter dark differently distributed scales. The preliminary public allow us detect significant density fluctuations discuss possible nonequilibrium scenarios explain hot structure, including tidal interactions neighboring galaxies, ram stripping from intracluster medium, merging events. In innermost region 1399, comparison between radio emission radio-emitting plasma displacing producing shocks X-ray-emitting gas. do nuclear source X-rays, pose upper limit ~4 1039 (0.1-2.4 keV) its luminosity. found 1404 well represented single symmetric follows stellar light 8 kpc. similar "central" component At pressure gas produces strong asymmetries Finally, properties point-source population, finding evidence correlation excess 1399.