Testing the Limits of AGN Feedback and the Onset of Thermal Instability in the Most Rapidly Star-forming Brightest Cluster Galaxies
Testing the Limits of AGN Feedback and the Onset of Thermal Instability in the Most Rapidly Star-forming Brightest Cluster Galaxies
复制标题
DOI：
10.3847/1538-4357/ac9790
复制
发表时间：
2022-07
期刊：
影响因子：
--
通讯作者：
M. Calzadilla;M. McDonald;M. Donahue;B. McNamara;K. Fogarty;M. Gaspari;M. Gitti;H. Russell;G. Tremblay;G. Voit;F. Ubertosi
中科院分区：
文献类型：
--
作者：
M. Calzadilla;M. McDonald;M. Donahue;B. McNamara;K. Fogarty;M. Gaspari;M. Gitti;H. Russell;G. Tremblay;G. Voit;F. Ubertosi
我们提出了新的，深，窄和宽带哈勃太空望远镜观测的七个最恒星形成最明亮的星系团（BCGs）。连续谱相减[OII]图揭示了这些BCGs中温暖（T = 104 K）电离气体细丝的详细复杂结构，使我们能够测量空间分辨的星星形成速率（SFR）为1060 -600 M/yr−1。我们比较了这些系统和文献中其他系统的SFR与它们的簇内介质冷却速率（M今冷），这些速率是从钱德拉X射线档案数据测量的，发现最佳拟合关系为log（SFR）=（1.66±0.17）log（M今冷）+（−3.22 ± 0.38），固有散射为0.39 ± 0.09 dex。这个比单位斜率更陡的斜率意味着随着M的冷却，热气体（T = 107 K）转化为年轻恒星的效率越来越高，或者相反，在最强的冷核心中，活动星系核反馈的有效性逐渐降低。我们还试图了解我们在集群核心中观察到的这些多相细丝的物理范围。我们表明，对于第一次，多相气体的平均程度总是小于半径，在该半径处的冷却时间达到1 Gyr，t冷却/t ff的配置文件的tcool，并观察到X射线腔。这意味着多相细丝、冷却核心的热力学和X射线气泡的动力学之间存在密切联系。有趣的是，我们发现一个一对一的相关性之间的平均程度冷多相丝和半径在冷却时间达到0.5 Gyr，这可能是一个普遍的凝聚时标在集群核心的指示。
We present new, deep, narrow- and broadband Hubble Space Telescope observations of seven of the most star-forming brightest cluster galaxies (BCGs). Continuum-subtracted [OII] maps reveal the detailed, complex structure of warm (T ∼ 104 K) ionized gas filaments in these BCGs, allowing us to measure spatially resolved star formation rates (SFRs) of ∼60–600 M ⊙yr−1. We compare the SFRs in these systems and others from the literature to their intracluster medium cooling rates ( Ṁcool ), measured from archival Chandra X-ray data, finding a best-fit relation of log(SFR)=(1.66±0.17)log(Ṁcool) + (−3.22 ± 0.38) with an intrinsic scatter of 0.39 ± 0.09 dex. This steeper-than-unity slope implies an increasingly efficient conversion of hot (T ∼ 107 K) gas into young stars with increasing Ṁcool , or conversely a gradual decrease in the effectiveness of AGN feedback in the strongest cool cores. We also seek to understand the physical extent of these multiphase filaments that we observe in cluster cores. We show, for the first time, that the average extent of the multiphase gas is always smaller than the radii at which the cooling time reaches 1 Gyr, the t cool/t ff profile flattens, and that X-ray cavities are observed. This implies a close connection between the multiphase filaments, the thermodynamics of the cooling core, and the dynamics of X-ray bubbles. Interestingly, we find a one-to-one correlation between the average extent of cool multiphase filaments and the radius at which the cooling time reaches 0.5 Gyr, which may be indicative of a universal condensation timescale in cluster cores.