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标题：Exploring the multiphase medium in MKW 08: from the central active galaxy up to cluster scales
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作者：A. Tümer ; F. Tombesi ; H. Bourdin 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：629
页码：1-15
DOI：10.1051/0004-6361/201935660
语种：English
出版社：EDP Sciences
摘要：Context.The study of the brightest cluster galaxy (BCG) coronae embedded in noncool core (NCC) galaxy clusters is crucial to understand the BCG’s role in galaxy cluster evolution as well as the activation of the self-regulated cooling and heating mechanism in the central regions of galaxy clusters.Aims.We explore the X-ray properties of the intracluster medium (ICM) of the NCC galaxy cluster MKW 08 and the BCG corona, along with their interface region. With recent and deep archivalChandraobservations, we study the BCG corona in detail, and with archivalXMM-Newtonobservations, we investigate the implications of the central active galactic nuclei (AGN) on the BCG.Methods.We carry out imaging and spectral analyses of MKW 08 with archivalXMM-NewtonandChandraX-ray observations.Results.Our spectral analysis suggests the presence of a central AGN by a power-law with a photon index of Γ ≃ 1.8 at the core of its BCG. Although the ICM does not exhibit a cluster scale cool core, the BCG manifests itself as a mini cool core characterized by a cooling time as short as 64 Myr atr = 3 kpc centered at the galaxy. The isothermality of the BCG corona seems to favor mechanical feedback from the central AGN as the major source of gas heating. The gas pressure profile of this mini cool core suggests that the BCG coronal gas reaches pressure equilibrium with the hotter and less dense ICM inside an interface of nearly constant pressure, delimited by radii 4 ≤ r ≤ 10 kpc at the galactic center. As revealed by the presence of a metal enriched tail (Z ≃ 0.5–0.9Z⊙) extending up to 40 kpc, the BCG corona seems to be experiencing ram-pressure stripping by the surrounding ICM and/or interacting with a nearby galaxy, IC 1042.
关键词：enX-rays: galaxies: clustersgalaxies: individual: NGC 5718galaxies: clusters: individual: MKW 08galaxies: clusters: intracluster medium