The Resolved Sunyaev–Zel’dovich Profiles of Nearby Galaxy Groups
The Resolved Sunyaev–Zel’dovich Profiles of Nearby Galaxy Groups
复制标题
已解决的邻近星系群的孙亚耶夫-泽尔多维奇剖面
DOI：
10.3847/1538-4357/ac1796
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
J. Bregman
中科院分区：
文献类型：
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作者：
Cameron T. Pratt;Zhijie Qu;J. Bregman
星系群中的许多重子被认为是通过反馈被驱赶到很远的距离（≳R 500），但对这种扩展气体的限制性观察很少。这项工作提出了质量范围 log10(M500[M⊙])=13.6–13.9 内 10 个邻近星系群的堆叠样本的 Sunyaev-Zel'dovich (SZ) 剖面图。我们使用普朗克合作组织公开的 y 地图以及我们自己根据最新版本的普朗克数据构建的 y 地图来测量 SZ 剖面。从最新发布的数据中提取的 y 地图产生了高达 3 R 500 的显着 SZ 检测。此外，这些数据的叠加剖面与包括 AGN 反馈的模拟一致。我们使用最新普朗克数据的最佳拟合模型表明，R 500 内的重子分数约为 5.6%。这明显低于宇宙值约 16%，支持了重子已被 AGN 反馈驱动至大半径的观点。最后，我们在~2 R 500 附近发现了一个显着的（~3σ）“碰撞”特征，这很可能是内部吸积激波的特征。
Many of the baryons in galaxy groups are thought to have been driven out to large distances (≳R 500) by feedback, but there are few constraining observations of this extended gas. This work presents the resolved Sunyaev–Zel’dovich (SZ) profiles for a stacked sample of 10 nearby galaxy groups within the mass range log10(M500[M⊙])=13.6–13.9 . We measured the SZ profiles using the publicly available y-map from the Planck Collaboration as well as our own y-maps constructed from more recent versions of Planck data. The y-map extracted from the latest data release yielded a significant SZ detection out to 3 R 500. In addition, the stacked profile from these data was consistent with simulations that included AGN feedback. Our best-fit model using the latest Planck data suggested a baryon fraction ≈5.6% within R 500. This is significantly lower than the cosmic value of ≈16%, supporting the idea that baryons have been driven to large radii by AGN feedback. Lastly, we discovered a significant (∼3σ) “bump” feature near ∼2 R 500 that is most likely the signature of internal accretion shocks.