Thursday, June 6, 2013

1306.0907 (J. Hlavacek-Larrondo et al.)

Probing the extreme realm of AGN feedback in the massive galaxy cluster, RX J1532.9+3021    [PDF]

J. Hlavacek-Larrondo, S. W. Allen, G. B. Taylor, A. C. Fabian, R. E. A. Canning, N. Werner, J. S. Sanders, C. K. Grimes, S. Ehlert, A. von der Linden
We present a detailed Chandra, XMM-Newton, VLA and HST analysis of the highly X-ray luminous galaxy cluster RX J1532.9+3021 (z=0.3613), one of the strongest cool core clusters known. Using new, deep 90 ks Chandra observations, we confirm the presence of a western X-ray cavity or bubble, and report on a newly discovered eastern X-ray cavity. The total mechanical power associated with these AGN-driven outflows is 22+/-9*10^44 erg/s, and is sufficient to offset the cooling, indicating that AGN feedback still provides a viable solution to the cooling flow problem even in extreme cool core clusters. Based on the distribution of the optical filaments, as well as a jet-like structure seen in the 325 MHz VLA radio map, we suggest that the cluster harbours older AGN-driven outflows along the north to south direction. The jet of the central AGN is therefore either precessing, or sloshing-induced motions have caused the outflows to change directions. There are also hints of an X-ray depression to the north aligned with the 325 MHz jet-like structure, which may represent an older X-ray cavity known as a ghost cavity. This would be be the highest redshift ghost cavity discovered to date. We further find evidence of a cold front (r=65 kpc) that coincides with the outermost edge of the western X-ray cavity and the edge of the radio mini-halo. The common location of the cold front with the edge of the radio mini-halo supports the idea that the latter originates from relativistic electrons being reaccelerated due to sloshing induced turbulence. Alternatively, its coexistence with the edge of the X-ray cavity may be due to cool gas being dragged out by the outburst. We confirm that the central AGN is highly sub-Eddington and conclude that a >10^10M_sun black hole or a rapidly spinning black hole is favoured to explain both the AGN radiative-inefficiency and the powerful X-ray cavities. [Abridged]
View original: http://arxiv.org/abs/1306.0907

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