Xray cavities in a sample of 83 SPT-selected clusters galaxies. Tracing the evolution of AGN feedback in clusters of galaxies out to z=1.2

Journal Article · Mon May 18 00:00:00 EDT 2015 · The Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/805/1/35· OSTI ID:1326609

Hlavacek-Larrondo, J. ; McDonald, M. ; Benson, B. A.; Forman, W. R.; Allen, S. W.; Bleem, L. E.; Ashby, M. L. N.; Bocquet, S. ; Brodwin, M. ; Dietrich, J. P.; Jones, C.; Liu, J.; Reichardt, C. L.; Saliwanchik, B. R.; Saro, A.; Schrabback, T.; Song, J.; Stalder, B.; Vikhlinin, A.; Zenteno, A.

X-ray cavities are key tracers of mechanical (or radio mode) heating arising from the active galactic nuclei (AGNs) in brightest cluster galaxies (BCGs). We report on a survey for X-ray cavities in 83 massive, high-redshift ($$0.4\lt z\lt 1.2$$) clusters of galaxies selected by their Sunyaev-Zel’dovich signature in the South Pole Telescope data. Based on Chandra X-ray images, we find a total of six clusters having symmetric pairs of surface brightness depressions consistent with the picture of radio jets inflating X-ray cavities in the intracluster medium (ICM). The majority of these detections are of relatively low significance and require deeper follow-up data in order to be confirmed. Further, this search will miss small (<10 kpc) X-ray cavities that are unresolved by Chandra at high ($$z\gtrsim 0.5$$) redshift. Despite these limitations, our results suggest that the power generated by AGN feedback in BCGs has remained unchanged for over half of the age of the universe ($$\gt 7$$ Gyr at $$z\sim 0.8$$). On average, the detected X-ray cavities have powers of $$(0.8-5)\times {{10}^{45}}\ {\rm erg}\ {{{\rm s}}^{-1}}$$, enthalpies of $$(3-6)\times {{10}^{59}}\ {\rm erg}$$, and radii of ~17 kpc. Integrating over 7 Gyr, we find that the supermassive black holes in BCGs may have accreted 10(8) to several $${{10}^{9}}\,{{M}_{\odot }}$$ of material to power these outflows. This level of accretion indicates that significant supermassive black hole growth may occur not only at early times, in the quasar era, but at late times as well. We also find that X-ray cavities at high redshift may inject an excess heat of 0.1–1.0 keV per particle into the hot ICM above and beyond the energy needed to offset cooling. Although this result needs to be confirmed, we note that the magnitude of excess heating is similar to the energy needed to preheat clusters, break self-similarity, and explain the excess entropy in hot atmospheres.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: SPT
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1326609
• Report Number(s): FERMILAB-PUB-14-547-AE; arXiv:1410.0025; 1319598
• Journal Information: The Astrophysical Journal (Online), Vol. 805, Issue 1; ISSN 1538-4357
• Publisher: Institute of Physics (IOP)
• Country of Publication: United States
• Language: English

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79 ASTRONOMY AND ASTROPHYSICS