Driving hot and cold gas flows in galaxies with feedback from massive black holes

利用大质量黑洞的反馈驱动星系中的热气流和冷气流

• 批准号: ST/P004636/2
• 负责人: Helen Russell
• 金额: $ 43.15万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FP004636%2F2
• 关键词: Driving; hot; cold; gas; flows

Modern astronomy seeks to understand how the galaxies and large clusters of galaxies that we see in the local universe formed in the thirteen billion years since the Big Bang. Computer simulations that include the key physics of gravity and gas cooling can successfully reproduce the distribution of galaxies and clusters on large scales. However, these models fail to recover the structure of individual galaxies. In particular, the models predict too much gas cooling in galaxies producing large cold gas reservoirs and huge bursts of star formation, which are not observed. A heating mechanism is required to prevent this. Whilst low mass galaxies can be heated by winds from stars and supernovae, massive galaxies require the much more powerful jets of high-energy particles launched in the strong gravitational environment around a supermassive black hole. These black holes are a million to several billion times the mass of our Sun and sit at the centre of every galaxy, including our Milky Way. However, we do not yet understand how a black hole that is the size of the solar system is able to heat an entire galaxy and its surroundings on scales roughly a billion times larger. Energetic feedback from a supermassive black hole is one of the most important unsolved problems in galaxy evolution and is the focus of this proposal.Both the star formation and black hole activity are fuelled by cold gas at the centres of massive galaxies, whose detailed structure can now be resolved by the new ALMA Observatory. ALMA is a large array of 66 high precision radio dishes located in the Atacama Desert of Chile that is transforming our understanding of galaxy evolution by providing the most incredibly detailed view of cold gas in the nearby and distant universe. Over ALMA's four years of science operations, I have led the analyses of five of the most massive gas-rich galaxies that were observed at 'high priority' during the early science phase of the commissioning. I am the PI of three new programs, a co-author of a further six programs and I have led the analysis of observations from each of the four ALMA observing cycles so far. In five of the six galaxies observed, large filaments of cold molecular gas extend a distance equivalent to the diameter of the Milky Way, and form bright, cold rims around giant bubbles of radio-emitting plasma inflated by the jet. The inflation of these huge bubbles pumps a substantial amount of heat into the surroundings that suppresses gas cooling, but my results now show that the bubbles also lift massive gas flows from the galaxy centre. The gas later falls back in a circulating flow feeding central gas disks. These cold gas disks fuel supermassive black holes, thereby sustaining jets and limiting star formation in the host galaxies.Over the next five years, I will expand my pathfinder observations to a large sample of galaxies with the primary goals of understanding the origin of the cold gas, tracing gas inflows that feed supermassive black holes and determining how the jet-blown bubbles regulate star formation and black hole activity by lifting gas from the galaxy's core. My analysis will focus on mapping the gas velocities in the extended filaments to determine how they can be lifted by the bubbles and identifying correlations between the jet power and the mass, velocity and extent of gas outflows that can be incorporated into galaxy simulations. I will also study the structure of subsequent inflows of gas feeding central disks to show how this feedback from a supermassive black hole can be sustained to restrict the growth of galaxies.

现代天文学试图了解我们在宇宙中看到的星系和大型星系团是如何在大爆炸后的130亿年中形成的。包括重力和气体冷却的关键物理学的计算机模拟可以成功地再现大尺度上星系和星系团的分布。然而，这些模型无法恢复单个星系的结构。特别是，这些模型预测星系中过多的气体冷却会产生大量的冷气库和巨大的星星形成爆发，而这些都没有被观察到。需要加热机制来防止这种情况。虽然低质量星系可以被来自恒星和超新星的风加热，但大质量星系需要在超大质量黑洞周围的强引力环境中发射更强大的高能粒子射流。这些黑洞的质量是我们太阳的一百万到几十亿倍，位于每个星系的中心，包括我们的银河系。然而，我们还不明白一个太阳系大小的黑洞如何能够加热整个星系及其周围的环境，其规模大约是太阳系的十亿倍。超大质量黑洞的能量反馈是星系演化中最重要的未解决的问题之一，也是本提案的重点。星星的形成和黑洞活动都是由大质量星系中心的冷气体提供燃料的，新的阿尔马天文台现在可以解决其详细结构。阿尔马是位于智利阿塔卡马沙漠的66个高精度射电天线的大型阵列，它通过提供附近和遥远宇宙中最令人难以置信的冷气体详细视图来改变我们对星系演化的理解。在阿尔马四年的科学运作中，我领导了对五个最大质量的富含气体的星系的分析，这些星系在调试的早期科学阶段被“高度优先”观察到。我是三个新项目的PI，另外六个项目的合著者，到目前为止，我已经领导了对四个阿尔马观测周期中每个周期的观测结果的分析。在观测到的六个星系中的五个星系中，冷分子气体的大细丝延伸的距离相当于银河系的直径，并在喷射膨胀的无线电发射等离子体的巨大气泡周围形成明亮，寒冷的边缘。这些巨大气泡的膨胀将大量的热量泵入周围环境，抑制气体冷却，但我现在的结果表明，气泡也从星系中心提升了大量的气体流。气体随后以循环流的形式回落到福尔斯中，供给中央气盘。这些冷气盘为超大质量黑洞提供燃料，从而维持喷流并限制宿主星系中的星星形成。在接下来的五年里，我将把我的探路者观测扩展到大样本星系，主要目标是了解冷气的起源，追踪供给超大质量黑洞的气体流入，并确定喷流-吹出的气泡通过提升星系核心的气体来调节星星的形成和黑洞的活动。我的分析将集中在绘制扩展细丝中的气体速度，以确定气泡如何提升它们，并确定喷射功率与气体流出的质量，速度和程度之间的相关性，这些相关性可以纳入星系模拟。我还将研究随后流入的气体供给中心盘的结构，以显示来自超大质量黑洞的反馈如何能够持续限制星系的生长。

项目成果

Testing the Limits of AGN Feedback and the Onset of Thermal Instability in the Most Rapidly Star-forming Brightest Cluster Galaxies

• DOI: 10.3847/1538-4357/ac9790
• 发表时间: 2022-07
• 期刊: The Astrophysical Journal
• 作者: M. Calzadilla;M. McDonald;M. Donahue;B. McNamara;K. Fogarty;M. Gaspari;M. Gitti;H. Russell;G. Tremblay;G. Voit;F. Ubertosi

AGN feeding and feedback in M84: from kiloparsec scales to the Bondi radius

• DOI: 10.1093/mnras/stad824
• 发表时间: 2023-01
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: C. J. Bambic;H. Russell;C. Reynolds;A. Fabian;B. McNamara;P. Nulsen

Turbulent magnetic fields in merging clusters: a case study of Abell 2146

合并星团中的湍流磁场：阿贝尔 2146 的案例研究

• DOI: 10.1093/mnras/stac594
• 发表时间: 2022
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Chadayammuri U

Atmospheric pressure and molecular cloud formation in early-type galaxies

早期星系中的大气压力和分子云形成

• 发表时间: 2021
• 期刊: arXiv e-prints
• 作者: Babyk Iurii

Weighing merging galaxy clusters with idealised simulations

通过理想化模拟权衡合并星系团

• DOI: 10.5281/zenodo.4911781
• 发表时间: 2021
• 期刊: Galaxy Cluster Formation II
• 作者: Chadayammuri Urmila