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

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; McNamara, Brian R.; Reichardt, Christian L.

Abstract

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 gsim1061 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 (${P}_{\mathrm{cav}}=(9.4\pm 5.8)\times {10}^{45}$ 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.

Citation

Calzadilla, M. S., McDonald, M., Bayliss, M., Benson, B. A., Bleem, L. E., Brodwin, M., Edge, A. C., Floyd, B., Gupta, N., Hlavacek-Larrondo, J., McNamara, B. R., & Reichardt, C. L. (2019). Discovery of a Powerful >1061 erg AGN Outburst in the Distant Galaxy Cluster SPT-CLJ0528-5300. Astrophysical Journal Letters, 887(1), Article L17. https://doi.org/10.3847/2041-8213/ab5b07

• Journal Article Type: Article
• Acceptance Date: Nov 23, 2019
• Online Publication Date: Dec 10, 2019
• Publication Date: Dec 10, 2019
• Deposit Date: Jan 22, 2020
• Publicly Available Date: Jan 22, 2020
• Journal: Astrophysical Journal
• Print ISSN: 2041-8205
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 887
• Issue: 1
• Article Number: L17
• DOI: https://doi.org/10.3847/2041-8213/ab5b07
• Public URL: https://durham-repository.worktribe.com/output/1278302