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Title: Deep Chandra , HST-COS, and megacam observations of the Phoenix cluster: Extreme star formation and AGN feedback on hundred kiloparsec scales

In this study, we present new ultraviolet, optical, and X-ray data on the Phoenix galaxy cluster (SPT-CLJ2344-4243). Deep optical imaging reveals previously undetected filaments of star formation, extending to radii of ~50–100 kpc in multiple directions. Combined UV-optical spectroscopy of the central galaxy reveals a massive (2 × 10 9 M ), young (~4.5 Myr) population of stars, consistent with a time-averaged star formation rate of 610 ± 50 M yr –1. We report a strong detection of O vi λλ1032,1038, which appears to originate primarily in shock-heated gas, but may contain a substantial contribution (>1000 M yr –1) from the cooling intracluster medium (ICM). We confirm the presence of deep X-ray cavities in the inner ~10 kpc, which are among the most extreme examples of radio-mode feedback detected to date, implying jet powers of 2 – 7 × 10 45 erg s –1. We provide evidence that the active galactic nucleus inflating these cavities may have only recently transitioned from "quasar-mode" to "radio-mode," and may currently be insufficient to completely offset cooling. A model-subtracted residual X-ray image reveals evidence for prior episodes of strong radio-mode feedback at radii of ~100 kpc, with extended "ghost" cavities indicating amore » prior epoch of feedback roughly 100 Myr ago. This residual image also exhibits significant asymmetry in the inner ~200 kpc (0.15R 500), reminiscent of infalling cool clouds, either due to minor mergers or fragmentation of the cooling ICM. Taken together, these data reveal a rapidly evolving cool core which is rich with structure (both spatially and in temperature), is subject to a variety of highly energetic processes, and yet is cooling rapidly and forming stars along thin, narrow filaments.« less
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [1] ;  [6] ;  [7] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ;  [3] ;  [13] ;  [1] ;  [14] ;  [15] ;  [1]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  2. Univ. of Waterloo, Waterloo, ON (Canada); Perimeter Institute for Theoretical Physics, Waterloo (Canada)
  3. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  4. Argelander-Institut fur Astronomie, Bonn (Germany)
  5. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Harvard Univ., Cambridge, MA (United States)
  6. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)
  7. Univ. of Chicago, Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
  8. Univ. of Kentucky, Lexington, KY (United States)
  9. Durham Univ., Durham (United Kingdom)
  10. Institute of Astronomy, Cambridge (United Kingdom)
  11. Huntingdon Institute for X-ray Astronomy, Huntingdon, PA (United States)
  12. Univ. de Montreal, Montreal, Quebec (Canada)
  13. Univ. of Chicago, Chicago, IL (United States)
  14. Univ. of Hawaii, Honolulu, HI (United States)
  15. Univ. of Maryland, College Park, MD (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1538-4357; arXiv eprint number arXiv:1508.05941
Grant/Contract Number:
AC02-07CH11359; AC02-06CH11357
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 811; Journal Issue: 2; Journal ID: ISSN 1538-4357
Institute of Physics (IOP)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; galaxies: active; galaxies: starburst; X-rays: galaxies: clusters; ultraviolet: galaxies; X-rays; galaxies; active; clusters; starburst; ultraviolet
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1249109