The Clusters Hiding in Plain Sight (CHiPS) Survey: A First Discovery of a Massive Nearby Cluster around PKS 1353−341
The Clusters Hiding in Plain Sight (CHiPS) Survey: A First Discovery of a Massive Nearby Cluster around PKS 1353−341
复制标题
隐藏在平视视野中的星团 (CHiPS) 巡天：首次发现 PKS 1353−341 附近的大型星团
DOI：
10.3847/1538-4357/aace55
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
A. Stark
中科院分区：
文献类型：
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作者：
T. Somboonpanyakul;M. McDonald;Henry W. Lin;B. Stalder;A. Stark
我们介绍隐藏在平视中的星团 (CHiPS) 巡天的第一个结果，该巡天旨在发现附近新的大质量星系团，这些星系团在 ROSAT 全天巡天中被错误地识别为孤立的点源。我们展示了对第一个新发现的低红移（z = 0.223）星系团的钱德拉 X 射线观测，该星系团具有中央 X 射线亮点源 PKS 1353−341。去除点源对簇核心的贡献（Lnuc ∼ 1.8 × 1044 erg s−1）后，我们确定簇的各种属性。松弛的 X 射线形态、中心温度下降以及 400 Myr 左右的中心冷却时间的存在表明它是一个强大的冷核星团。中央星系似乎正在以 6.2 ± 3.6 M⊙ yr−1 的速度形成恒星，相当于经典冷却预测的 ∼1%。中央星系中的超大质量黑洞似乎以爱丁顿速率的 0.1% 吸积，总功率输出为 5 × 1045 erg s−1，几乎平均分配辐射能和机械能。我们看到在 200 kpc 半径处存在局部过量熵的微弱证据，如果属实，可能意味着核心最近发生了一次（~180 Myr）能量爆发，并已迅速上升到更大的半径。将该星团的体积特性与其他已知星团的体积特性进行比较（例如，总质量 M500 ，辐射热 X 射线光度 LX 为 7 × 1044 erg s−1），我们发现该星团的质量足够大，足以被普朗克巡天探测到（但未得到证实），而且其亮度也足够高，如果没有这样的星团，它也会在 ROSAT 全天巡天中被识别为星团。明亮的中心点光源。这一发现证明了 CHiPS 调查有可能发现具有极端中心特性的大量附近星团，而这些星团可能在之前的调查中被遗漏或错误识别。
We introduce the first result of the Clusters Hiding in Plain Sight (CHiPS) survey, which aims to discover new nearby massive galaxy clusters that were incorrectly identified as isolated point sources in the ROSAT All-sky Survey. We present a Chandra X-ray observation of our first newly discovered low-redshift (z = 0.223) galaxy cluster with a central X-ray bright point source, PKS 1353−341. After removing the point source contribution to the cluster core (Lnuc ∼ 1.8 × 1044 erg s−1), we determine various properties of the cluster. The presence of a relaxed X-ray morphology, a central temperature drop, and a central cooling time around 400 Myr indicates that it is a strong cool-core cluster. The central galaxy appears to be forming stars at the rate of 6.2 ± 3.6 M⊙ yr−1, corresponding to ∼1% of the classical cooling prediction. The supermassive black hole in the central galaxy appears to be accreting at ∼0.1% of the Eddington rate with a total power output of ∼5 × 1045 erg s−1, split nearly equally between radiative and mechanical power. We see weak evidence of localized excess entropy at a radius of 200 kpc, which, if true, could imply a recent (∼180 Myr) energetic outburst in the core that has risen buoyantly to a larger radius. Comparing the cluster’s bulk properties with those of other known clusters (e.g., the total mass M500 is , and the bolometric X-ray luminosity LX is 7 × 1044 erg s−1), we show that this cluster, which is massive enough that it was detected (but not confirmed) by the Planck survey, is also sufficiently luminous that it would have been identified as a cluster in the ROSAT All-sky Survey if it did not have such a bright central point source. This discovery demonstrates the potential of the CHiPS survey to find massive nearby clusters with extreme central properties that may have been missed or misidentified by previous surveys.