2025/11/17 by Omoruyi, Osase, Tremblay, Grant, Baum, Stefi A. +14
Physics and Astronomy · #Accretion (finance) #Active galactic nucleus #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics of Galaxies (astro-ph.GA) #Cluster (spacecraft) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #High Energy Astrophysical Phenomena (astro-ph.HE) #Intracluster medium #Plasma #Radiative cooling #Surface brightness
paper · doi:10.48550/arxiv.2511.13817
openalex publication_date 2025/11/17 · openalex created_date 2025/11/20 · openalex updated_date 2026/07/28
To examine how AGN feedback shapes the intracluster medium (ICM) and fuels black hole accretion in the cool-core galaxy cluster Abell 2597, we present deep (∼600 ks) Chandra X-ray observations complemented by archival GMRT radio and SINFONI near-infrared data. Radio-mode AGN activity has inflated seven X-ray cavities and driven one to three potential weak shocks (M ∼ 1.05-1.14) extending to ∼ 150 kpc, suggesting recurrent outbursts occurring on ∼ 107 year timescales. We also detect a narrow, ∼57 kpc X-ray surface brightness deficit-a potential plasma depletion layer-likely shaped by residual sloshing motions that amplified magnetic fields and/or displaced gas within the cluster core. Although the AGN injects ∼ 1044 erg s-1 of energy, comparable to the cluster's cooling luminosity, radiative cooling persists at ∼15 M\odot yr-1, replenishing the billion solar mass cold gas reservoir at the heart of the brightest cluster galaxy. Sustaining this level of activity requires a continuous fuel supply, yet the estimated Bondi accretion power (∼ 2 × 1043 erg s-1) falls an order of magnitude short of the observed cavity power, suggesting that "hot" gas fueling is insufficient. Instead, archival ALMA observations continue to support a chaotic cold accretion scenario, where turbulence-driven condensation fuels the AGN at rates exceeding Bondi accretion, sustaining a self-regulated feedback cycle that repeatedly shapes the core of Abell 2597.