AGN feeding and feedback in M84: from kiloparsec scales to the Bondi radius
AGN feeding and feedback in M84: from kiloparsec scales to the Bondi radius
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DOI：
10.1093/mnras/stad824
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发表时间：
2023-01
影响因子：
4.8
通讯作者：
C. J. Bambic;H. Russell;C. Reynolds;A. Fabian;B. McNamara;P. Nulsen
中科院分区：
文献类型：
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作者：
C. J. Bambic;H. Russell;C. Reynolds;A. Fabian;B. McNamara;P. Nulsen
我们介绍了迄今为止对室女座星系团中的M84星系进行的最深入的钱德拉观测，包括由遗留观测提供的超过840kS的数据和最近的730kS活动。增加的信噪比使我们能够从X射线晕的千帕秒尺度到邦迪半径Rb来研究供给M84中心超大质量黑洞的吸积流的来源。获得了M84‘S活动星系核延伸到邦迪半径的四个扇区的温度、金属丰度和出射密度分布。吸积流不是由黑洞的势能决定的，而是受到活动星系核的双极射电喷流的强烈影响。沿喷流轴线，密度分布符合Ne∝r−1，但垂直于喷流，密度分布变平。无线电喷流在流动中产生了显著的不对称性，违反了邦迪吸积的一个关键假设。内部千帕秒内的温度基本不变，只有从0.6 keV到0.7 keV的微小上升，接近Rb，没有证据表明黑洞造成了温度上升。邦迪吸积率比从活动星系核光度和喷流功率推断的速率高出四个数量级以上。在垂直于喷流的扇区，测量结果一致；然而，在沿喷流的北区，吸积率低>；4σ，这可能是由于X射线气体中的空洞所致。我们的测量提供了对负责星系团中射电模式反馈的活动星系核的燃料的独特洞察。
We present the deepest Chandra observation to date of the galaxy M84 in the Virgo Cluster, with over 840 ks of data provided by legacy observations and a recent 730 ks campaign. The increased signal-to-noise ratio allows us to study the origins of the accretion flow feeding the supermassive black hole in the centre of M84 from the kiloparsec scales of the X-ray halo to the Bondi radius, RB. Temperature, metallicity, and deprojected density profiles are obtained in four sectors about M84’s active galactic nucleus (AGN), extending into the Bondi radius. Rather than being dictated by the potential of the black hole, the accretion flow is strongly influenced by the AGN’s bipolar radio jets. Along the jet axis, the density profile is consistent with ne ∝ r−1; however, the profiles flatten perpendicular to the jet. Radio jets produce a significant asymmetry in the flow, violating a key assumption of Bondi accretion. Temperature in the inner kiloparsec is approximately constant, with only a slight increase from 0.6 to 0.7 keV approaching RB, and there is no evidence for a temperature rise imposed by the black hole. The Bondi accretion rate $\dot{M}_{\rm B}$ exceeds the rate inferred from AGN luminosity and jet power by over four orders of magnitude. In sectors perpendicular to the jet, $\dot{M}_{\rm B}$ measurements agree; however, the accretion rate is >4σ lower in the North sector along the jet, likely due to cavities in the X-ray gas. Our measurements provide unique insight into the fuelling of AGN responsible for radio mode feedback in galaxy clusters.