We investigate the formation of circumnuclear gas structures from the tidal disruption of molecular clouds in galactic nuclei, by means of smoothed particle hydrodynamics simulations. We model galactic nuclei as composed of a supermassive black hole (SMBH) and a nuclear star cluster (NSC) and consider different mass ratios between the two components. We find that the relative masses of the SMBH and the NSC have a deep impact on the morphology of the circumnuclear gas. Extended disks form only inside the sphere of influence of the SMBH. In contrast, compact rings naturally form outside the SMBH's sphere of influence, where the gravity is dominated by the NSC. This result is in agreement with the properties of the Milky Way's circumnuclear ring, which orbits outside the SMBH sphere of influence. Our results indicate that compact circumnuclear rings can naturally form outside the SMBH sphere of influence.
The cold molecular gas in the circumnuclear disk (CND) of radio galaxies provides critical information for understanding the mass accretion onto active galactic nuclei. We present the first detection and maps of HCN J=1-0 and HCO+ J=1-0 emission lines from the circumnuclear region of a nearby radio galaxy, NGC 4261, using the Northern Extended Millimeter Array. Both molecular lines are detected at a radial velocity of +-700 km/s relative to the systemic velocity of the galaxy, and they arise from a CND with an outer radius of 100 pc. The velocity fields of HCN and HCO+ are fitted with a Kepler…
Emission line observations of circumnuclear gas disks in the ALMA era have begun to resolve molecular gas tracer kinematics near supermassive black holes (BHs), enabling highly precise mass determination in the best cases. The ngVLA is capable of extremely high spatial resolution imaging of the CO(1-0) transition at 115 GHz for nearby galaxies. Furthermore, its high (anticipated) emission line sensitivity suggests this array can produce benchmark BH mass measurements. We discuss lessons learned from gas-dynamical modeling of recent ALMA data sets and also compare ALMA and ngVLA CO simulations …
We present Gemini Near-infrared Integral Field Spectrograph (NIFS) observations of the inner $1.5\times1.5$ kpc$^2$ of the narrow-line Seyfert 1 galaxy Mrk 42 at a spatial resolution of 60 pc and spectral resolution of 40 km s$^{-1}$. The emission-line flux and equivalent width maps clearly show a ring of circumnuclear star formation regions (CNSFRs) surrounding the nucleus with radius of $\sim$500 pc. The spectra of some of these regions show molecular absorption features which are probably of CN, TiO or VO, indicating the presence of massive evolved stars in the thermally pulsing asymptotic …
The host galaxy conditions for rapid supermassive black hole growth are poorly understood. Narrow-line Seyfert 1 (NLS1) galaxies often exhibit high accretion rates and are hypothesized to be prototypes of active galactic nuclei (AGN) at an early stage of their evolution. We present VLT MUSE NFM-AO observations of Mrk 1044, the nearest super-Eddington accreting NLS1. Together with archival MUSE WFM data we aim to understand the host galaxy processes that drive Mrk 1044's black hole accretion. We extract the faint stellar continuum emission from the AGN-deblended host and perform spatially resol…
Utilizing the Atacama Large Millimeter/submillimeter Array (ALMA), we present CS line maps in five rotational lines ($J_{\rm u}=7, 5, 4, 3, 2$) toward the circumnuclear disk (CND) and streamers of the Galactic Center. Our primary goal is to resolve the compact structures within the CND and the streamers, in order to understand the stability conditions of molecular cores in the vicinity of the supermassive black hole (SMBH) Sgr A*. Our data provide the first homogeneous high-resolution ($1.3'' = 0.05$ pc) observations aiming at resolving density and temperature structures. The CS clouds have si…
The shape of the ambient circumnuclear medium (ACM) density profile can probe the history of accretion onto the central supermassive black hole in galaxies and the circumnuclear environment. However, due to the limitation of the instrument resolution, the density profiles of the ACM for most of galaxies remain largely unknown. In this work, we propose a novel method to measure the ACM density profile of active galactic nucleus (AGN) by the equilibrium between the radiation pressure on the warm absorbers (WAs, a type of AGN outflows) and the drag pressure from the ACM. We study the correlation …
A series of gravitational instabilities in a circumnuclear gas disk (CND) are required to trigger gas transport to a central supermassive black hole (SMBH) and ignite Active Galactic Nuclei (AGNs). A test of this scenario is to investigate whether an enhanced molecular gas mass surface density ($Σ_{\rm mol}$) is found in the CND-scale of quasars relative to a comparison sample of inactive galaxies. Here we performed sub-kpc resolution CO(2-1) observations with ALMA of four low-redshift ($z \sim 0.06$), luminous ($\sim 10^{45}$ erg s$^{-1}$) quasars with each matched to a different star-forming…
We present $\sim0.10^{\prime\prime}-$resolution Atacama Large Millimeter/submillimeter Array (ALMA) CO(2$-$1) imaging of the arcsecond-scale ($r \approx 150$ pc) dusty molecular disk in the giant elliptical galaxy NGC 3258. The data provide unprecedented resolution of cold gas disk kinematics within the dynamical sphere of influence of a supermassive black hole, revealing a quasi-Keplerian central increase in projected rotation speed rising from 280 km s$^{-1}$ at the disk's outer edge to $>400$ km s$^{-1}$ near the disk center. We construct dynamical models for the rotating disk and fit beam-…
The active galactic nucleus (AGN) phenomena results from a supermassive black hole accreting its surrounding gaseous and dusty material. The infrared (IR) regime provides most of the information to characterize the dusty structures that bridge from the galaxy to the black hole, providing clues to the black hole growth and host galaxy evolution. Over the past several decades, with the commissioning of various ground, airborne and space IR observing facilities, our interpretations of the AGN circumnuclear structures have advanced significantly through improved understanding of how their dust emi…
Numerical models of gas inflow towards a supermassive black hole (SMBH) show that star formation may occur in such an environment through the growth of a gravitationally unstable gas disc. We consider the effect of nuclear activity on such a scenario. We present the first three-dimensional grid-based radiative hydrodynamic simulations of direct collisions between infalling gas streams and a $4 \times 10^6~\text{M}_\odot$ SMBH, using ray-tracing to incorporate radiation consistent with an active galactic nucleus (AGN). We assume inflow masses of $ \approx 10^5~\text{M}_\odot$ and explore radiat…
Chemical Features in the Circumnuclear Disk of the Galactic Center
银河系中心的环核盘（CND）暴露于来自超大质量黑洞Sgr A* 和恒星活动的许多高能现象。这些高能活动可以通过与UV光子、宇宙射线、X射线和冲击波的相互作用影响CND中的化学成分。我们的目标是约束的物理条件存在于CND的化学建模所观察到的分子物种检测到的对it.We分析了一组选定的分子线数据采取对一个位置在西南瓣的CND与IRAM 30米和APEX 12米望远镜和推导出的柱密度的每个分子使用大速度梯度（LVG）分析。确定的化学成分进行比较与时间相关的气体颗粒化学模型的基础上UCL\_CHEM代码，包括冲击波的影响，不同的物理参数。检测CO、HCN、HCO $^+$、HNC、CS、SO、SiO、NO、CN、H $_2$ CO、HC $_3$ N、N $_2$ H $^+$和H $_3$ O $^+$等分子，并获得它们的柱密度。从LVG分析获得的总氢密度范围在$2 \times 10^4$和$1 \times 10^6\,$ cm $^{-3}$之间，并且大多数物种指示大约几个$\times 10^5\,$ cm $^{-3}$的值，其低于对应于罗氏极限的值，这表明CND是潮汐不稳定的。在密度为$\sim10^4\,$ cm $^{-3}$、宇宙射线电离率高、速度为$>10^{-15} \,$ s $^{-1}$或速度为$> 40\,$ km s $^{-1}$的激波的情况下，化学模型…
We perform the first three-dimensional radiation hydrodynamical simulations that investigate the growth of intermediate-mass BHs (IMBHs) embedded in massive self-gravitating, dusty nuclear accretion disks. We explore the dependence of mass accretion efficiency on the gas metallicity $Z$ and mass injection at super-Eddington accretion rates from the outer galactic disk $\dot{M}_{\rm in}$, and find that the central BH can be fed at rates exceeding the Eddington rate only when the dusty disk becomes sufficiently optically thick to ionizing radiation. In this case, mass outflows from the disk owin…
Modeling the Milky Way Circumnuclear Disk: Rosettes and Rings
Northwestern University（西北大学）；Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA)（天体物理学跨学科探索与研究中心）；Department of Physics and Astronomy, Northwestern University（西北大学物理与天文系）；School of Natural Sciences, Institute for Advanced Study（高等研究院自然科学学院）
The nearby, luminous infrared galaxy (LIRG) NGC 7469 hosts a Seyfert nucleus with a circumnuclear star-forming ring and is thus the ideal local laboratory for investigating the starburst--AGN connection in detail. We present integral-field observations of the central 1.3 kpc region in NGC 7469 obtained with the JWST Mid-InfraRed Instrument. Molecular and ionized gas distributions and kinematics at a resolution of {\sim}100 pc over the 4.9 - 7.6μm region are examined to study gas dynamics influenced by the central AGN. The low-ionization [Fe II] λ5.34μm and [Ar II] λ6.99μm lines are bright on t…
We studied the magnetic field structures and dynamics of magnetized multiphase gas on parsec scales around supermassive black holes by using global 3D magnetohydrodynamics (MHD) simulations. We considered the effect of radiative cooling and X-ray heating due to active galactic nuclei (AGNs). The gas disk consists of a multiphase gas with (1) cold ($\leq 10^3$ K) and thin, and (2) warm ($\sim 10^4$ K) and thick components with a wide range of number densities. The turbulent magnetic energy at maximum is comparable to the thermal and turbulent kinetic energies in the turbulent motion. We confirm…
MICONIC: The multiphase circumnuclear region of Centaurus A as seen with JWST/MIRI MRS observations. I. Spectral inventory and properties of the warm molecular disk
Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris（索邦大学，法国国家科学研究中心，UMR 7095，巴黎天文台）；SRON Netherlands Institute for Space Research（荷兰空间研究所）；Leiden Observatory, Leiden University（莱顿天文台，莱顿大学）；Observatoire de Paris, PSL University, Sorbonne Université, LUX（巴黎天文台，PSL大学，索邦大学，LUX）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙国家研究委员会-国家航空航天技术研究所）；Department of Physics and Astronomy, Universiteit Gent（根特大学物理与天文学系）；Telespazio UK for the European Space Agency (ESA)（欧洲航天局（ESA）旗下泰雷兹阿莱尼亚太空英国分公司）；European Space Agency, c/o Space Telescope Science Institute（欧洲航天局，代管于太空望远镜科学研究所）
Massive molecular gas has been discovered in giant elliptical galaxies at the centers of galaxy clusters. To reveal its role in active galactic nucleus (AGN) feedback in those galaxies, we construct a semianalytical model of gas circulation. This model especially focuses on the massive molecular gas (interstellar cold gas on a scale of ~ 10 kpc) and the circumnuclear disk (~< 0.5 kpc). We consider the destruction of the interstellar cold gas by star formation and the gravitational instability for the circumnuclear disk. Our model can reproduce the basic properties of the interstellar cold gas …
We present 0\farcs{14}-resolution Atacama Large Millimeter/submillimeter Array (ALMA) CO(2$-$1) observations of the circumnuclear gas disk in UGC 2698, a local compact galaxy. The disk exhibits regular rotation with projected velocities rising to 450 km s$^{-1}$ near the galaxy center. We fit gas-dynamical models to the ALMA data cube, assuming the CO emission originates from a dynamically cold, thin disk, and measured the mass of the supermassive black hole (BH) in UGC 2698 to be $M_{\mathrm{BH}} = (2.46 \pm{0.07}$ [$1σ$ stat] $^{+0.70}_{-0.78}$ [sys])$\times 10^9$ $M_\odot$. UGC 2698 is part…
High-Resolution [CI] $({^3\mathrm{P}_2}\rightarrow{^3\mathrm{P}_1})$ and CO $(J=7\rightarrow6)$ Observations of Circumnuclear Disks in Nearby Seyfert Galaxies
Astronomical Institute, Tohoku University（东北大学天文研究所）；Department of Cosmosciences, Graduate School of Science, Hokkaido University（北海道大学理学研究宇宙科学科）；Department of Electrical, Electronic and Computer Engineering, Fukui University of Technology（福井工业大学电气电子计算机工程系）；School of Science and Technology, Kwansei Gakuin University（关西学院大学理工学部）；Department of Physics, Faculty of Science, Hokkaido University（北海道大学理学部物理学科）
In Wada, Tsukamoto, and Kokubo (2019), we proposed for the first time that a new class of planets, "blanets" (i.e., black hole planets), can be formed around supermassive black holes (SMBHs) in the galactic center. Here, we investigate the dust coagulation processes and physical conditions of the blanet formation outside the snow line ($r_{snow} \sim $ several parsecs) in more detail, especially considering the effect of the radial advection of the dust aggregates. We found that a dimensionless parameter $α= v_t^2/c_s^2$, where $v_t$ is the turbulent velocity and $c_s$ is the sound velocity, d…
We combine results from deep ALMA observations of massive ($M_*>10^{10}\;M_{\odot}$) galaxies at different redshifts to show that the column density of their inter stellar medium (ISM) rapidly increases towards early cosmic epochs. Our analysis includes objects from the ASPECS and ALPINE large programs, as well as individual observations of $z\sim 6$ QSO hosts. When accounting for non-detections and correcting for selection effects, we find that the median surface density of the ISM of the massive galaxy population evolves as $\sim(1+z)^{3.3}$. This means that the ISM column density towards th…
As part of the Measuring Black Holes in Below Milky Way-mass (M$^\star$) galaxies (MBHBM$^\star$) Project, we present a dynamical measurement of the supermassive black hole (SMBH) mass in the nearby lenticular galaxy NGC 3593, using cold molecular gas $^{12}$CO(2-1) emission observed at an angular resolution of $\approx0''.3$ ($\approx10$ pc) with the Atacama Large Millimeter/submillimeter Array (ALMA). Our ALMA observations reveal a circumnuclear molecular gas disc (CND) elongated along the galaxy major axis and rotating around the SMBH. Using dynamical modelling, the molecular gas kinematics…
We present near-infrared 1.1-1.3 and 1.3-1.6 $μ$m spectra of the Ly$α$-luminous quasar PSO J006.1240+39.2219 at $z=6.617$ obtained with the NIRSPEC spectrograph at the Keck-II telescope. The spectra cover the CIV $λ$1549, CIII] $λ$1909 emission lines and part of the UV continuum of the quasar. From the NIRSPEC observations of PSO J006.1240+39.2219, we constrain the spectral slope of its UV continuum to be $α_λ=-1.35\pm0.26$ and measure an absolute magnitude of $M_{1450}=-25.60$. Using the scaling relation between black hole mass, width of the CIV line and ultraviolet continuum luminosity, we d…
We present 1"-resolution ALMA observations of the circumnuclear disk (CND) and the environment around SgrA*. The images unveil the presence of small spatial scale CO (J=3-2) molecular "cloudlets" within the central pc of the Milky Way, moving at high speeds, up to 300 km/s along the line-of-sight. The CO-emitting structures show intricate morphologies: extended and filamentary at high negative-velocities (v_LSR < -150 km/s), more localized and clumpy at extreme positive-velocities (v_LSR > +200 km/s). Based on the pencil-beam CO absorption spectrum toward SgrA* synchrotron emission, we also pr…
ALMA CO(2-1) Gas Dynamics in NGC 315: A Multi-Method Benchmark for Supermassive Black Hole Mass Measurement
University of Michigan（密歇根大学）；Brigham Young University（杨百翰大学）；University of Science, VNU-HCM（越南国立大学胡志明市分校科学大学）；Viet Nam National University Ho Chi Minh City（越南国立大学胡志明市）；University of Vienna（维也纳大学）
Radio emission from the high- and super-Eddington accreting active galactic nuclei (AGNs) has various origins: a persistent jet, the magnetized corona and the wind-like outflows. It is now still unclear which is the leading mechanism responsible for the observed radio emission and how the radio emission is related to other characteristic parameters such as the Eddington ratio and black hole mass. In this paper, we present the 5 GHz Very Large Array (VLA) observational results of a sample of 25 extremely high Eddington accreting supermassive black holes (EESBHs, the Eddington ratio close to or …
