Possible AGN shock heating in the cool-core galaxy cluster Abell 478

摘要: We present a detailed X-ray study of the intracluster medium (ICM) nearby cool-core galaxy cluster Abell 478 (z ¼ 0:088), based on Chandra and XMM-Newton observations. Using wavelet-smoothing hardness analysis, we derive temperature maps A478, revealing surprising amount structure for an apparently well-relaxed cluster. find broadband spectral fits yield temperatures that are significantly hotter than those obtained with XMM-Newton, but Fe ionization shows good agreement. show discrepancy is slightly reduced when comparing spectra from regions selected to enclose nearly isothermal gas. However, by simulating multitemperature fitting them single-temperature model, no significant difference between indicating nonisothermality cannot fully explain discrepancy. have discovered four hot spots located 30 50 kpc center, where gas roughly factor 2 higher in surrounding material. estimate combined excess thermal energy these be 3 � 1 ðÞ ;10 59 ergs. The location suggestive common origin within core, which hosts active galactic nucleus. This also possesses pair cavities coincident weak radio lobes, as reported previous associated less 10% spots. presence could indicate strong-shock heating central source, one first such detections high resolution Chandra, probe mass distribution coreandfind itto becharacterized bya logarithmic slopeof 0:35 0:22, whichis significantlyflatter anNFW (Navarro, Frenk, White) cusp consistent recent strong-lensing results number clusters. Subject headingg cosmology: observations — galaxies: clusters: general individual (A478) X-rays: clusters