Evidence for AGN-regulated Cooling in Clusters at z ∼ 1.4: A Multiwavelength View of SPT-CL J0607-4448

Masterson, Megan; McDonald, Michael; Ansarinejad, Behzad; Bayliss, Matthew; Benson, Bradford A.; Bleem, Lindsey E.; Calzadilla, Michael S.; Edge, Alastair C.; Floyd, Benjamin; Kim, Keunho J.; Khullar, Gourav; Somboonpanyakul, Taweewat

Abstract

We present a multiwavelength analysis of the galaxy cluster SPT-CL J0607-4448 (SPT0607), which is one of the most distant clusters discovered by the South Pole Telescope at z = 1.4010 ± 0.0028. The high-redshift cluster shows clear signs of being relaxed with well-regulated feedback from the active galactic nucleus (AGN) in the brightest cluster galaxy (BCG). Using Chandra X-ray data, we construct thermodynamic profiles and determine the properties of the intracluster medium. The cool-core nature of the cluster is supported by a centrally peaked density profile and low central entropy (${K}_{0}={18}_{-9}^{+11}$ keV cm2), which we estimate assuming an isothermal temperature profile due to the limited spectral information given the distance to the cluster. Using the density profile and gas cooling time inferred from the X-ray data, we find a mass-cooling rate ${\dot{M}}_{\mathrm{cool}}={100}_{-60}^{+90}\,{M}_{\odot }$ yr−1. From optical spectroscopy and photometry around the [O ii] emission line, we estimate that the BCG star formation rate is ${\mathrm{SFR}}_{[{\rm{O}}\,{\rm\small{II}}]}={1.7}_{-0.6}^{+1.0}\,{M}_{\odot }$ yr−1, roughly two orders of magnitude lower than the predicted mass-cooling rate. In addition, using ATCA radio data at 2.1 GHz, we measure a radio jet power ${P}_{\mathrm{cav}}={3.2}_{-1.3}^{+2.1}\times {10}^{44}$ erg s−1, which is consistent with the X-ray cooling luminosity (${L}_{\mathrm{cool}}={1.9}_{-0.5}^{+0.2}\times {10}^{44}$ erg s−1 within rcool = 43 kpc). These findings suggest that SPT0607 is a relaxed, cool-core cluster with AGN-regulated cooling at an epoch shortly after cluster formation, implying that the balance between cooling and feedback can be reached quickly. We discuss the implications for these findings on the evolution of AGN feedback in galaxy clusters.

Citation

Masterson, M., McDonald, M., Ansarinejad, B., Bayliss, M., Benson, B. A., Bleem, L. E., …Somboonpanyakul, T. (2023). Evidence for AGN-regulated Cooling in Clusters at z ∼ 1.4: A Multiwavelength View of SPT-CL J0607-4448. Astrophysical Journal, 944(2), Article 164. https://doi.org/10.3847/1538-4357/acae9e

• Journal Article Type: Article
• Acceptance Date: Dec 23, 2022
• Online Publication Date: Feb 27, 2023
• Publication Date: Feb 20, 2023
• Deposit Date: Jun 20, 2023
• Publicly Available Date: Jun 20, 2023
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 944
• Issue: 2
• Article Number: 164
• DOI: https://doi.org/10.3847/1538-4357/acae9e