Discovery of a Powerful >1061 erg AGN outburst in the Distant Galaxy Cluster SPT-CLJ0528-5300

Journal Article · 09 December 2019 · The Astrophysical Journal. Letters

DOI: https://doi.org/10.3847/2041-8213/ab5b07 · OSTI ID:1581140

Calzadilla, Michael S.; McDonald, Michael; Bayliss, Matthew; Benson, Bradford A.; Bleem, Lindsey E.; Brodwin, Mark; Edge, Alastair C.; Floyd, Benjamin; Gupta, Nikhel; Hlavacek-Larrondo, Julie

We present ~103 ks of Chandra observations of the galaxy cluster SPT-CLJ0528-5300 (SPT0528, z = 0.768). This cluster harbors the most radio-loud (L _1.4GHz = 1.01 × 10³³ erg s^-1 Hz^-1) central active galactic nucleus (AGN) of any cluster in the South Pole Telescope (SPT) Sunyaev–Zeldovich survey with available X-ray data. We find evidence of AGN-inflated cavities in the X-ray emission, which are consistent with the orientation of the jet direction revealed by Australia Telescope Compact Array radio data. The combined probability that two such depressions—each at ~1.4–1.8σ significance, oriented ~180° apart and aligned with the jet axis—would occur by chance is 0.1%. At 10⁶¹ erg, the outburst in SPT0528 is among the most energetic known in the universe, and certainly the most powerful known at z > 0.25. This work demonstrates that such powerful outbursts can be detected even in shallow X-ray exposures out to relatively high redshifts (z ~ 0.8), providing an avenue for studying the evolution of extreme AGN feedback. The ratio of the cavity power ( erg s^-1) to the cooling luminosity (L _cool = (1.5 ± 0.5) × 10⁴⁴ erg s^-1) for SPT0528 is among the highest measured to date. If, in the future, additional systems are discovered at similar redshifts with equally high P _cav/L _cool ratios, it would imply that the feedback/cooling cycle was not as gentle at high redshifts as in the low-redshift universe.

• Research Organization: Argonne National Laboratory (ANL); Argonne National Laboratory (ANL), Argonne, IL (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: National Aeronautic and Space Administration (NASA); USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• Contributing Organization: SPT collaboration
• Grant/Contract Number: AC02-06CH11357; AC02-07CH11359
• OSTI ID: 1581140
• Report Number(s): FERMILAB-PUB--19-662-AE; arXiv:1911.12828; 157470
• Journal Information: The Astrophysical Journal. Letters, Journal Name: The Astrophysical Journal. Letters Journal Issue: 1 Vol. 887; ISSN 2041-8205
• Publisher: Institute of Physics (IOP)Copyright Statement
• Country of Publication: United States
• Language: English