Shaken Snow Globes: Kinematic Tracers of the Multiphase Condensation Cascade in Massive Galaxies, Groups, and Clusters
Shaken Snow Globes: Kinematic Tracers of the Multiphase Condensation Cascade in Massive Galaxies, Groups, and Clusters
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DOI：
10.3847/1538-4357/aaaa1b
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发表时间：
2017-09
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通讯作者：
M. Gaspari;M. McDonald;S. Hamer;F. Brighenti;P. Temi;M. Gendron-Marsolais;J. Hlavacek-Larrondo;A. Edge;N. Werner;P. Tozzi;M. Sun;J. Stone;G. Tremblay;M. Hogan;D. Eckert;S. Ettori;H. Yu;V. Biffi;S. Planelles
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作者：
M. Gaspari;M. McDonald;S. Hamer;F. Brighenti;P. Temi;M. Gendron-Marsolais;J. Hlavacek-Larrondo;A. Edge;N. Werner;P. Tozzi;M. Sun;J. Stone;G. Tremblay;M. Hogan;D. Eckert;S. Ettori;H. Yu;V. Biffi;S. Planelles
我们提出了一种新的方法来约束大质量星系、星系群和星系团中的湍流和体运动，探索模拟和观测。正如最近出现的自上而下的多相冷凝，热气体晕在共空间性和热力学方面与所有其他相紧密相连。当热晕（~ 107 K）受到亚音速湍流的扰动时，热（~ 104 K）电离和中性细丝从湍流漩涡中凝结出来。这些峰通过混沌冷吸积(CCA)凝结成冷分子云(<100 K)在核心中降雨。我们表明，所有相位都是紧密联系在一起的系综（大孔径）速度色散沿着视线。这种相关性出现在互补的长期AGN反馈模拟和高分辨率CCA运行中，并得到了Hitomi和Perseus星系团中新的积分场单元测量结果的证实。系综多相气体分布（从紫外波段到射电波段）具有明显的谱线展宽（σv,los≈100-200）和轻微的谱线位移。另一方面，铅笔束探测（作为对AGN背光的H吸收）对小尺度云进行采样，显示出较小的宽度和显著的线移（对于那些落向AGN的云），由于湍流间歇性而增加了散射。我们提出了72个观测到的星团/群核心中温暖的Hα+[N ii]气体的损失的新集合σv：约束与模拟一致，可以用作湍流速度的可靠代理，特别是对于具有挑战性的热等离子体（否则需要极长时间的x射线照射）。最后，我们证明了物理驱动判据C≡tcool/teddy≈1最好地描述了观察到的星团和团中的凝聚程度区域和多相气体的存在。该方法可以应用于许多可用的光谱数据集，并可以在下一代多波长任务中大大提高我们对多相晕的理解。
We propose a novel method to constrain turbulence and bulk motions in massive galaxies, galaxy groups, and clusters, exploring both simulations and observations. As emerged in the recent picture of top-down multiphase condensation, hot gaseous halos are tightly linked to all other phases in terms of cospatiality and thermodynamics. While hot halos (∼107 K) are perturbed by subsonic turbulence, warm (∼104 K) ionized and neutral filaments condense out of the turbulent eddies. The peaks condense into cold molecular clouds (<100 K) raining in the core via chaotic cold accretion (CCA). We show that all phases are tightly linked in terms of the ensemble (wide-aperture) velocity dispersion along the line of sight. The correlation arises in complementary long-term AGN feedback simulations and high-resolution CCA runs, and is corroborated by the combined Hitomi and new Integral Field Unit measurements in the Perseus cluster. The ensemble multiphase gas distributions (from the UV to the radio band) are characterized by substantial spectral line broadening (σv,los ≈ 100–200 ) with a mild line shift. On the other hand, pencil-beam detections (as H i absorption against the AGN backlight) sample the small-scale clouds displaying smaller broadening and significant line shifts of up to several 100 (for those falling toward the AGN), with increased scatter due to the turbulence intermittency. We present new ensemble σv,los of the warm Hα+[N ii] gas in 72 observed cluster/group cores: the constraints are consistent with the simulations and can be used as robust proxies for the turbulent velocities, in particular for the challenging hot plasma (otherwise requiring extremely long X-ray exposures). Finally, we show that the physically motivated criterion C ≡ tcool/teddy ≈ 1 best traces the condensation extent region and the presence of multiphase gas in observed clusters and groups. The ensemble method can be applied to many available spectroscopic data sets and can substantially advance our understanding of multiphase halos in light of the next-generation multiwavelength missions.