To examine how active galactic nucleus (AGN) feedback shapes the intracluster medium (ICM) and fuels black hole accretion in the cool-core galaxy cluster A2597, 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 yr 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⊙ 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 Atacama Large Millimeter/submillimeter Array 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 A2597.
A Deep Chandra View of A2597: Bubbles, Shocks, Cold Fueling, and a Plasma Depletion Layer / Omoruyi, O., Tremblay, G., Baum, S.A., Clarke, T.E., Dabhade, P., Fabian, A., Gaspari, M., Gulati, S., Kharb, P., Markevitch, M., Nulsen, P., O'Dea, C.P., Randall, S., Raychaudhury, S., Vaddi, S., Vikhlinin, A., Zuhone, J.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 997:1(2026), pp. 1-24. [10.3847/1538-4357/ae2006]
A Deep Chandra View of A2597: Bubbles, Shocks, Cold Fueling, and a Plasma Depletion Layer
Gaspari M.;
2026
Abstract
To examine how active galactic nucleus (AGN) feedback shapes the intracluster medium (ICM) and fuels black hole accretion in the cool-core galaxy cluster A2597, 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 yr 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⊙ 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 Atacama Large Millimeter/submillimeter Array 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 A2597.| File | Dimensione | Formato | |
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