The Hot and Energetic Universe: The formation and growth of the earliest supermassive black holes
James Aird, Andrea Comastri, Marcella Brusa, Nico Cappelluti, Alberto Moretti, Eros Vanzella, Marta Volonteri, David Alexander, Jose Manuel Afonso, Fabrizio Fio… 展开作者
James Aird, Andrea Comastri, Marcella Brusa, Nico Cappelluti, Alberto Moretti, Eros Vanzella, Marta Volonteri, David Alexander, Jose Manuel Afonso, Fabrizio Fiore, Ioannis Georgantopoulos, Kazushi Iwasawa, Andrea Merloni, Kirpal Nandra, Ruben Salvaterra, Mara Salvato, Paola Severgnini, Kevin Schawinski, Francesco Shankar, Cristian Vignali, Fabio Vito
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Supporting paper for the science theme The Hot and Energetic Universe to be implemented by the Athena+ X-ray observatory (http://www.the-athena-x-ray-observatory.eu). 8 pages, 5 figures
A crucial challenge in astrophysics over the coming decades will be to understand the origins of supermassive black holes (SMBHs) that lie at the centres of most, if not all, galaxies. The processes responsible for the initial formation of these SMBHs and their early growth via accretion - when they are seen as Active Galactic Nuclei (AGN) - remain unknown. To address this challenge, we must identify low luminosity and obscured z>6 AGNs, which represent the bulk of early SMBH growth. Sensitive X-ray observations are a unique signpost of accretion activity, uncontaminated by star formation processes, which prevent reliable AGN identification at other wavelengths (e.g. optical, infrared). The Athena+ Wide Field Imager will enable X-ray surveys to be carried out two orders of magnitude faster than with Chandra or XMM-Newton, opening a new discovery space and identifying over 400 z>6 AGN, including obscured sources. Athena+ will also play a fundamental role to enhance the scientific return of future multiwavelength facilities that will probe the physical conditions within the host galaxies of early SMBHs, which is vital for understanding how SMBHs form, what fuels their subsequent growth, and to assess their impact on the early Universe. Follow-up of samples of z>6 galaxies with the Athena+ X-ray Integral Field Unit could also reveal the presence of highly obscured AGNs, thanks to the detection of strong iron lines. Thus, Athena+ will enable the first quantitative measurements of the extent and distribution of SMBH accretion in the early Universe.
Blazars are Active Galactic Nuclei characterized by relativistic jets launched in the vicinity of the central engine (i.e. a supermassive black hole), that are oriented close to our line of sight. Their peculiar orientation makes them very efficient tracers of the overall jetted population, and due to their brightness they can be visible up to very high redshifts. A deep knowledge of these objects can provide fundamental clues to the models of formation and growth of the first supermassive black holes, but their search in the early Universe must be careful and follow a systematic approach. The…
The Universe is filled with a diffuse background of MeV gamma-rays and PeV neutrinos, whose origins are unknown. Here, we propose a scenario that can account for both backgrounds simultaneously. Low-luminosity active galactic nuclei have hot accretion flows where thermal electrons naturally emit soft gamma rays via Comptonization of their synchrotron photons. Protons there can be accelerated via turbulence or reconnection, producing high-energy neutrinos via hadronic interactions. We demonstrate that our model can reproduce the gamma-ray and neutrino data. Combined with a contribution by hot c…
Building on the insight that primordial black holes can arise from the formation and subsequent gravitational collapse of bound states of stable supermassive elementary particles during the early radiation era, we offer a comprehensive picture describing the evolution and growth of the resulting mini-black holes through both the radiation and matter dominated phases, until the onset of (small scale) inhomogeneities. This is achieved by means of an exact metric solving Einstein's equations throughout both phases. We show that, thanks to a special enhancement effect producing an effective horizo…
Radio Monitoring of the Tidal Disruption Event Swift J164449.3+573451. I. Jet Energetics and the Pristine Parsec-Scale Environment of a Supermassive Black Hole
Quasi-periodic eruptions (QPEs), which are a new kind of X-ray bursts with a recurrence time of several hours, have been detected from supermassive black holes (SMBHs) in galactic nuclei. Recently, the two QPEs discovered by the \textit{eROSITA} show asymmetric light curves with a fast rise and a slow decline. Current models cannot explain the observational characteristics of QPEs. Here we show that QPEs can be generated from the Roche lobe overflows at each periapsis passage of an evolved star orbiting an SMBH. The properties of the companion stars are constrained via analytic estimations. We…
Constraining spins of supermassive black holes from TeV variability. II. fully general relativistic calculations
观测到了来自M87中心的TeV能量光子的快速变化，为估算超大质量黑洞（SMBH）的自旋提供了新的线索.我们扩展了Wang et al.（2008）的研究，包括所有的广义相对论效应。通过数值求解辐射无效吸积流的相对论流体动力学方程组，得到了黑洞周围的辐射场。在Kerr度规中计算了TeV光子对产生的辐射场的光学深度。我们发现，光学深度强烈依赖于：（1）吸积率为$\tautev\propto \dot{M}^{2.5-5.0}$;（2）黑洞自旋;（3）TeV源的位置。结合光学厚度和RIAF辐射的光谱能量分布，可以大大缓解RIAF模型中自旋与其他自由参数的强烈退化。我们将这个模型应用到M87中，发现黑洞的最小比角动量为$a\sim0.8$。本方法适用于M87类源与未来的TeV的排放量的检测，以限制SMBHs的自旋。
Stellar Stripping and Disruption in Disks around Supermassive Black Hole Binaries: Repeating nuclear transients prior to LISA events
Space Telescope Science Institute（太空望远镜科学研究所）；Johns Hopkins University（约翰斯·霍普金斯大学）；Niels Bohr International Academy, Niels Bohr Institute（尼尔斯·玻尔国际学院，尼尔斯·玻尔研究所）；Chungbuk National University（忠北国立大学）；Aoyama Gakuin University（青山学院大学）；University of Zurich（苏黎世大学）
The newly launched X-ray satellite, eRosita, has recently revealed two gigantic bubbles extending to ~80 degrees above and below the Galactic center. The morphology of these "eRosita bubbles" bears a remarkable resemblance to the Fermi bubbles previously discovered by the Fermi Gamma-ray Space Telescope and its counterpart, the microwave haze. The physical origin of these striking structures has been intensely debated; however, because of their symmetry about the Galactic center, they likely originate from some energetic outbursts from the Galactic center in the past. Here we propose a theoret…
Disk truncation triggers relativistic jet launching of a highly accreting supermassive black hole
Tohoku University（东北大学）；Nagoya City University（名古屋市立大学）；National Astronomical Observatory of Japan（日本国立天文台）；University of Miyazaki（宫崎大学）；The University of Osaka（大阪大学）；Shibaura Institute of Technology（芝浦工业大学）；National Institute of Technology, Ichinoseki College（国立工学期仙学院）
In radio-loud active galactic nuclei (AGNs), ultra-fast outflows (UFOs) were detected at the inclination angle of $\sim10^{\rm o}$--$70^{\rm o}$ away from jets. Except for the inclination angle of UFOs, the UFOs in radio-loud AGNs have similar properties to that in radio-quiet AGNs. The UFOs with such low inclination cannot be explained in the line-force mechanism. The magnetic-driving mechanism is suggested to explain the UFOs based on a self-similar solution with radiative transfer calculations. However, the energetics of self-similar solution need to be further confirmed based on numerical …
Tidal disruption events (TDEs) occur when a star is destroyed by a supermassive black hole at the center of a galaxy, temporarily increasing the accretion rate onto the black hole and producing a bright flare across the electromagnetic spectrum. Radio observations of TDEs trace outflows and jets that may be produced. Radio detections of the outflows from TDEs are uncommon, with only about one third of TDEs discovered to date having published radio detections. Here we present over two years of comprehensive, multi-radio frequency monitoring observations of the tidal disruption event AT2019azh t…
A population of highly energetic transient events in the centres of active galaxies
最近的全天巡天观测发现了新的瞬变现象。这些包括被中心超大质量黑洞破坏的恒星，以及能量比典型超新星高10-100倍的超新星。然而，在宿主星系的最内部区域明显发生的更有活力的瞬变现象的本质是激烈争论的。在这里，我们报告了迄今为止发现的最具能量的：PS1-10adi，总辐射能量约为2.3 x 10^52 erg。其光变曲线的缓慢演化和持续3年以上的窄谱线与已知的周期性黑洞变化类型不一致。所观察到的性质意味着由膨胀材料和大量周围致密物质之间的冲击相互作用提供动力。这种膨胀物质的合理来源是一颗被中心黑洞潮汐破坏的恒星，或者是一颗超新星。两者都可以满足能源预算。对于前者，我们将不得不援引一种新的、迄今为止还未发现的潮汐破裂恒星的变体，而超新星的起源则主要依赖于其核位置所产生的环境效应。值得注意的是，我们还发现PS1-10adi并不是一个孤立的案例。因此，我们推测，这一新的瞬态人口以前被忽视，由于不正确的关联与潜在的中央黑洞活动。
Energetic nuclear outbursts have been discovered in luminous and ultraluminous infrared galaxies (U/LIRGs) at unexpectedly high rates. To investigate this population of transients, we performed a search in mid-IR data from the Wide-field Infrared Survey Explorer (WISE) satellite and its NEOWISE survey to detect and characterise luminous and smoothly evolving transients in a sample of 215 U/LIRGs. We report three new transients, all with $ΔL > 10^{43}$ erg s$^{-1}$, in addition to two previously known cases. Their host galaxies are all part of major galaxy mergers, and through radiative transfe…
Stellar Collisions from Self-consistent Stellar Dynamics Around Growing Supermassive black Holes
Guangzhou University（广州大学）；Key Laboratory for Astronomical Observation and Technology of Guangzhou（广州市天文观测与技术重点实验室）；Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province（广东省教育厅天文学科学与技术研究实验室）；Universitat Politècnica de València（瓦伦西亚理工大学）；Max-Planck-Institute for Extraterrestrial Physics（马克斯·普朗克地外物理研究所）；Kavli Institute for Astronomy and Astrophysics（卡弗里天体物理学研究所）
