Deeply cooled core of the Phoenix galaxy cluster imaged by ALMA with the Sunyaev?Zel’dovich effect
Deeply cooled core of the Phoenix galaxy cluster imaged by ALMA with the Sunyaev?Zel’dovich effect
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ALMA 利用 Sunyaev?Zel’dovich 效应拍摄的凤凰星系团深冷核心
DOI：
10.1093/pasj/psaa009
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发表时间：
2020
影响因子：
2.3
通讯作者：
Yoshikawa Kohji
中科院分区：
文献类型：
--
作者：
Kitayama Tetsu;Ueda Shutaro;Akahori Takuya;Komatsu Eiichiro;Kawabe Ryohei;Kohno Kotaro;Takakuwa Shigehisa;Takizawa Motokazu;Tsutsumi Takahiro;Yoshikawa Kohji
我们在第三波段用阿塔卡马大毫米/亚毫米阵列(ALMA)测量了SPT-CL J2334-4243(菲尼克斯星系团)的热Sunyaev-Zel‘dovich效应(SZE)。SZE是用来自中央星系的墨迹在分辨率(对应于kpc的物理尺度)下成像的，峰值信噪比超过11。结合Chandra X射线图像，ALMA Sze数据进一步允许电子温度、密度和熵的非参数反投影。我们的方法可以最大限度地减少中心活动星系核和星系团内X射线吸收气体的污染，这两者都对X射线光谱有很大影响。在当前的测量误差范围内，我们没有发现SZE图像存在明显的不对称性或扰动。探测到的SZE信号显示出比其他遥远星系团更高的中心浓度，并与本地冷核星系团的平均压强分布相吻合。与任何红移的典型星团不同，气体温度向中心下降了至少5倍。我们发现冷却气体的内部温度为V。总而言之，我们的结果表明，在菲尼克斯星系团的这个半径内，气体确实在有效地冷却，并且几乎是等压的。
We present measurements of the thermal Sunyaev–Zel’dovich effect (SZE) toward SPT-CL J2334-4243 (the Phoenix galaxy cluster) atby the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 3. The SZE is imaged atresolution (corresponding to the physical scale ofkpc) withinkpc from the central galaxy, with the peak signal-to-noise ratio exceeding 11. Combined with the Chandra X-ray image, the ALMA SZE data further allow for non-parametric deprojection of electron temperature, density, and entropy. Our method can minimize contamination by the central active galactic nucleus and the X-ray absorbing gas within the cluster, both of which greatly affect the X-ray spectrum. We find no significant asymmetry or disturbance in the SZE image within the current measurement errors. The detected SZE signal shows much higher central concentration than other distant galaxy clusters and agrees well with the average pressure profile of local cool-core clusters. Unlike in typical clusters at any redshift, the gas temperature drops by at least a factor of 5 toward the center. We identifycool gas with temperaturekeV in the innerkpc. Taken together, our results imply that the gas is indeed cooling efficiently and nearly isobarically down to this radius in the Phoenix cluster.