The Detectability of AGN Cavities in Cooling-Flow Clusters
| Autor: | L. Bi^rzan, D. A. Rafferty, B. R. McNamara, P. E. J. Nulsen, M. W. Wise, Sebastian Heinz, Eric Wilcots |
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| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Active galactic nucleus Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Cooling flow Galaxy Duty cycle Observatory Intracluster medium Ophiuchus Galaxy formation and evolution Astrophysics::Galaxy Astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics |
| Popis: | Chandra X-ray Observatory has revealed X-ray cavities in many nearby cooling flow clusters. The cavities trace feedback from the central active galactic nulceus (AGN) on the intracluster medium (ICM), an important ingredient in stabilizing cooling flows and in the process of galaxy formation and evolution. But, the prevalence and duty cycle of such AGN outbursts is not well understood. To this end, we study how the cooling is balanced by the cavity heating for a complete sample of clusters (the Brightest 55 clusters of galaxies, hereafter B55). In the B55, we found 33 cooling flow clusters, 20 of which have detected X-ray bubbles in their ICM. Among the remaining 13, all except Ophiuchus could have significant cavity power yet remain undetected in existing images. This implies that the duty cycle of AGN outbursts with significant heating potential in cooling flow clusters is at least 60 % and could approach 100 %, but deeper data is required to constrain this further. 4 pages, 2 figures; to appear in the proceedings of "The Monsters' Fiery Breath", Madison, Wisconsin 1-5 June 2009, Eds. Sebastian Heinz & Eric Wilcots; added annotation to the figure |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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