Anatomy of a Cooling Flow: The Feedback Response to Pure Cooling in the Core of the Phoenix Cluster

• Main Authors: McDonald, M. (Author), McNamara, B. R. (Author), Voit, G. M. (Author), Bayliss, Matthew B (Author), Benson, B. A. (Author), Brodwin, M. (Author), Canning, R. E. A. (Author), Florian, M. K. (Author), Garmire, G. P. (Author), Gaspari, M. (Author), Gladders, M. D. (Author), Hlavacek-Larrondo, J. (Author), Kara, Erin A (Author), Reichardt, C. L. (Author), Russell, H. R. (Author), Saro, A. (Author), Sharon, K. (Author), Somboonpanyakul, T. (Author), Tremblay, G. R. (Author), Weeren, R. J. van (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), MIT Kavli Institute for Astrophysics and Space Research (Contributor)
• Format: Article
• Language: English
• Published: American Astronomical Society, 2020-11-18T22:35:21Z.
• Subjects: Article
• Online Access: Get fulltext

 We present new, deep observations of the Phoenix cluster from Chandra, the Hubble Space Telescope, and the Karl Jansky Very Large Array. These data provide an order-of-magnitude improvement in depth and/or angular resolution over previous observations at X-ray, optical, and radio wavelengths. We find that the one-dimensional temperature and entropy profiles are consistent with expectations for pure-cooling models. In particular, the entropy profile is well fit by a single power law at all radii, with no evidence for excess entropy in the core. In the inner ∼10 kpc, the cooling time is shorter than any other known cluster by an order of magnitude, while the ratio of the cooling time to freefall time (t cool/t ff) approaches unity, signaling that the intracluster medium is unable to resist multiphase condensation on kpc scales. The bulk of the cooling in the inner ∼20 kpc is confined to a low-entropy filament extending northward from the central galaxy, with t cool/t ff ∼ 1 over the length of the filament. In this filament, we find evidence for ∼1010 M o in cool (∼104 K) gas (as traced by the [O ii]λλ3726,3729 doublet), which is coincident with the low-entropy filament and absorbing soft X-rays. The bulk of this cool gas is draped around and behind a pair of X-ray cavities, presumably bubbles that have been inflated by radio jets. These data support a picture in which active galactic nucleus feedback is promoting the formation of a multiphase medium via uplift of low-entropy gas, either via ordered or chaotic (turbulent) motions.