The presence of supermassive black holes (SMBHs) with masses up to $M_\bullet\sim10^9M_\odot$ at redshifts $z\simeq7.5$ suggests that their seeds may have started to grow long before the reionization in ambient medium with pristine chemical composition. During their latest 500Myr episode of growing from $z\geq10$ to $z\sim7$ the black holes shine as luminous as $10^{11}\hbox{--}10^{12}L_\odot$, with a cumulative spectrum consisting of the intrinsic continuum from hot accretion disk, nebular hydrogen and helium spectral lines and free-free continuum from gas of host halos. Here we address the question of whether such a plain spectrum would allow us to trace evolution of these growing SMBHs. In our calculations we assume that host galaxies have stellar populations with masses smaller than the mass of their central black holes -- the so-called obese black hole galaxies. Within this model we show that for a sufficiently high mass of gas in a host galaxy -- not smaller than the mass of a growing black hole, the cumulative spectrum in the far-infrared reveals a sharp transition from a quasi-blackbody Rayleigh-Jeans spectrum of the black hole $\proptoλ^{-2}$ to a flat free-free nebular continuum $λ^{0.118}$ on longer wavelength limit. Once such a transition in the spectrum is resolved, the black hole mass can be inferred as a combination of the observed wavelength at the transition $λ_k$ and the corresponding spectral luminosity. Possible observability of this effect in spectra of growing high-$z$ SMBHs and determination of their mass with the upcoming JWST and the planned space project Spektr-M is briefly discussed.
Direct collapse black holes (DCBHs) formed from the collapse of atomically-cooled primordial gas in the early Universe are strong candidates for the seeds of supermassive BHs. DCBHs are thought to form in atomic cooling haloes in the presence of a strong molecule-dissociating, Lyman-Werner (LW) radiation field. Given that star forming galaxies are likely to be the source of the LW radiation in this scenario, ionizing radiation from these galaxies may accompany the LW radiation. We present cosmological simulations resolving the collapse of primordial gas into an atomic cooling halo, including t…
Proximity zones of high-redshift quasars are unique probes of supermassive black hole formation, but simultaneously explaining proximity zone sizes and black hole masses has proved to be challenging. We study the robustness of some of the assumptions that are usually made to infer quasar lifetimes from proximity zone sizes. We show that small proximity zones can be readily explained by quasars that vary in brightness with a short duty cycle of $f_\mathrm{duty}\sim 0.1$ and short bright periods of $t_\mathrm{on}\sim 10^4$ yr, even for long lifetimes. We further show that reconciling this with b…
Though half of cosmic starlight is absorbed by dust and reradiated at long wavelengths (3$μ$m-3mm), constraints on the infrared through millimeter galaxy luminosity function (the `IRLF') are poor in comparison to the rest-frame ultraviolet and optical galaxy luminosity function, particularly at z>2.5. Here we present a backward evolution model for interpreting number counts, redshift distributions, and cross-band flux density correlations in the infrared and submillimeter sky, from 70$μ$m-2mm, using a model for the IRLF out to the epoch of reionization. Mock submillimeter maps are generated by…
The correlation between the mass of supermassive black holes (SMBHs; $\mathcal{M}_{\rm BH}$) and their host galaxies ($\mathcal{M}_\star$) in the reionization epoch provides valuable constraints on their early growth. High-redshift quasars typically have a $\mathcal{M}_{\rm BH}$/$\mathcal{M}_\star$ ratio significantly elevated in comparison to the local value. However, the degree to which this apparent offset is driven by observational biases is unclear for the most distant quasars. To address this issue, we model the sample selection and measurement biases for a compilation of 20 quasars at $…
We present the first constraint on Faraday rotation measure (RM) at submillimeter wavelengths for the nucleus of M 87. By fitting the polarization position angles ($χ$) observed with the SMA at four independent frequencies around $\sim$230 GHz and interpreting the change in $χ$ as a result of \emph{external} Faraday rotation associated with accretion flow, we determine the rotation measure of the M 87 core to be between $-$7.5$\times$10$^{5}$ and 3.4$\times$10$^{5}$ rad/m$^{2}$. Assuming a density profile of the accretion flow that follows a power-law distribution and a magnetic field that is …
First Light And Reionization Epoch Simulations (FLARES) -- XIX: Supermassive black hole mergers in the early Universe and their environmental dependence
本研究利用 FLARES 宇宙学流体动力学放大模拟分析 $z=5$–10 的 SMBH 并合及其环境依赖，并预测 LISA 对高红移并合事件的探测率与模型敏感性。
The recent discovery of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.3 has exacerbated the time compression problem implied by the appearance of supermassive black holes only ~900 Myr after the big bang, and only ~500 Myr beyond the formation of Pop II and III stars. Aside from heralding the onset of cosmic reionization, these first and second generation stars could have reasonably produced the ~5-20 solar-mass seeds that eventually grew into z~6-7 quasars. But this process would have taken ~900 Myr, a timeline that appears to be at odds with the predictions of LCDM without …
The cosmic history of supermassive black hole (SMBH) growth is important for understanding galaxy evolution, reionization and the physics of accretion. Recent NuSTAR, Swift-BAT and \textit{Chandra} hard X-ray surveys have provided new constraints on the space density of heavily obscured Active Galactic Nuclei (AGN). Using the new X-ray luminosity function derived from these data, we here estimate the accretion efficiency of SMBHs and their contribution to reionization. We calculate the total ionizing radiation from active galactic nuclei (AGN) as a function of redshift, based on the X radiatio…
We search for high-redshift (z>4.5) X-ray AGNs in the deep central (off-axis angle <5.7') region of the 7 Ms Chandra Deep Field-South X-ray image. We compile an initial candidate sample from direct X-ray detections. We then probe more deeply in the X-ray data by using pre-selected samples with high spatial resolution NIR/MIR (HST 1.6 micron and Spitzer 4.5 micron) and submillimeter (ALMA 850 micron) observations. The combination of the NIR/MIR and submillimeter pre-selections allows us to find X-ray sources with a wide range of dust properties and spectral energy distributions (SEDs). We use t…
We present observations of [NII] 205 $μ$m, [OIII] 88 $μ$m and dust emission in a strongly-lensed, submillimeter galaxy (SMG) at $z=6.0$, G09.83808, with the Atacama Large Millimeter/submillimeter Array (ALMA). Both [NII] and [OIII] line emissions are detected at $>12σ$ in the 0.8$"$-resolution maps. Lens modeling indicates that the spatial distribution of the dust continuum emission is well characterized by a compact disk with an effective radius of 0.64$\pm$0.02 kpc and a high infrared surface brightness of $Σ_\mathrm{IR}=(1.8\pm0.3)\times10^{12}~L_\odot$ kpc$^{-2}$. This result supports that…
The paper presents a catalog of supermassive black holes (SMBH) shapened for the interferometric observations in millimeter and submillimeter wavelength ranges and based on the open sources. The catalog includes the name of the object, coordinates, angular distance, the mass, the angular size of the gravitational radius of SMBH, the integral flux of radiosource, related with SMBH, in the range $20÷900$~GHz which is considered to be used in Event Horizon Telescope, future space mission Millimetron and others. The catalog is intended for use during the planning of the interferometric observation…
Motivated by recent measurements of the number density of faint AGN at high redshift, we investigate the contribution of quasars to reionization by tracking the growth of central supermassive black holes in an update of the Meraxes semi-analytic model. The model is calibrated against the observed stellar mass function at $z\sim0.6-7$, the black hole mass function at $z\lesssim0.5$, the global ionizing emissivity at $z\sim2-5$ and the Thomson scattering optical depth. The model reproduces a Magorrian relation in agreement with observations at $z<0.5$ and predicts a decreasing black hole mass to…
We examine the contribution of high-redshift (z>6) active galactic nuclei (AGNs) to cosmic hydrogen reionization, by tracing the growth and ionizing output of the first generation of supermassive black holes (SMBHs). Our calculations are anchored to the observed population of z~6 quasars, and trace back the evolving spectral energy distributions (SEDs) of the accretion flows that power these early AGNs and consider a variety of growth histories, including super-Eddington accretion. Compared to a fixed-shape SED, the evolving thin disks can produce ionizing radiation that is higher by up to ~80…
We present a sub-kpc localization of the sites of supermassive black hole (SMBH) growth in three active galactic nuclei (AGN) at $z \sim 3$ in relation to the regions of intense star formation in their hosts. These AGNs are selected from Karl G. Jansky Very Large Array (VLA) and Atacama Large Millimeter/submillimeter Array (ALMA) observations in the HUDF and COSMOS, with the centimetric radio emission tracing both star formation and AGN, and the sub/millimeter emission by dust tracing nearly pure star formation. We require radio emission to be $\geqslant5\times$ more luminous than the level as…
While low mass, star forming galaxies are often considered as the primary driver of reionization, their actual contribution to the cosmic ultraviolet background is still uncertain, mostly because the escape fraction of ionizing photons is only poorly constrained. Theoretical studies have shown that efficient supernova feedback is a necessary condition to create paths through which ionizing radiation can escape into the intergalactic medium. We investigate the possibility that accreting supermassive black holes in early dwarf galaxies may provide additional feedback and enhance the leakage of i…
Supermassive black hole (SMBH) masses can be measured by resolving the dynamical influences of the SMBHs on spatially-resolved tracers of the central potentials. Modern long-baseline interferometers have enabled the use of molecular gas as such a tracer. We present here Atacama Large Millimeter/submillimeter Array observations of the elliptical galaxy NGC 7052 at 0.11 arcseconds (37 pc) resolution in the 12CO(2-1) line and 1.3mm continuum emission. This resolution is sufficient to resolve the region in which the potential is dominated by the SMBH. We forward model these observations, using a m…
WISDOM Project -- XXVIII. Molecular gas measurement of the supermassive black hole mass of the galaxy NGC 1387
University of Oxford（牛津大学）；European Southern Observatory（欧洲南方天文台）；Zentrum für Astronomie der Universität Heidelberg（海德堡大学天文学中心）；Cardiff University（卡迪夫大学）
We present a positive correlation between the mass of dense molecular gas ($M_{\rm dense}$) of $\sim 100$ pc scale circumnuclear disks (CNDs) and the black hole mass accretion rate ($\dot{M}_{\rm BH}$) in total 10 Seyfert galaxies, based on data compiled from the literature and an archive (median aperture $θ_{\rm med}$ = 220 pc). A typical $M_{\rm dense}$ of CNDs is 10$^{7-8}$ $M_\odot$, estimated from the luminosity of the dense gas tracer, the HCN($1-0$) emission line. Because dense molecular gas is the site of star formation, this correlation is virtually equivalent to the one between nucle…
As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project, we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotating early-type galaxy NGC4697. This estimate is based on Atacama Large Millimeter/submillimeter Array (ALMA) cycle-3 observations of the 12CO(2-1) emission line with a linear resolution of 29 pc (0.53"). We find that NGC4697 hosts a small relaxed central molecular gas disc with a mass of 1.6x10^7 Msun, co-spatial with the obscuring dust disc visible in optical Hubble Space Telescope (HST) imaging. We also resolve …
As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotating early-type galaxy NGC4429, that is barred and has a boxy/peanut-shaped bulge. This estimate is based on Atacama Large Millimeter/submillimeter Array (ALMA) cycle-2 observations of the 12CO(3-2) emission line with a linear resolution of ~13 pc (0"18x0"14). NGC4429 has a relaxed, flocculent nuclear disc of molecular gas that is truncated at small radii, likely due to the combined effects of gas stability and tida…
We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection of the [O III] 88 $μ$m line and rest-frame 90 $μ$m dust continuum emission in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier Field cluster MACS J0416.1-2403. This [O III] detection confirms the LBG with a spectroscopic redshift of $z = 8.3118 \pm 0.0003$, making this object one of the furthest galaxies ever identified spectroscopically. The observed 850 $μ$m flux density of $137 \pm 26$ $μ$Jy corresponds to a de-lensed total infrared (IR) luminosity of $L_{\rm IR} = (1.7 \pm 0.3) \times 1…
We report ALMA Cycle 0 observations at 1.3mm of LESS J033229.4-275619 (XID403), an Ultraluminous Infrared Galaxy at $z=4.75$ in the Chandra Deep Field South hosting a Compton-thick QSO. The source is not resolved in our data at a resolution of $\sim$0.75 arcsec, placing an upper-limit of 2.5 kpc to the half-light radius of the continuum emission from heated-dust. After deconvolving for the beam size, however, we found a $\sim3σ$ indication of an intrinsic source size of $0.27\pm0.08$ arcsec (Gaussian FWHM), which would correspond to $r_{half}\sim0.9\pm0.3$ kpc. We build the far-IR SED of XID40…
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…
A galaxy halo may contain a large number of intermediate mass black holes (IMBHs) with masses in the range of 10^{2-6} solar mass. We propose to directly detect these IMBHs by observing multiply imaged QSO-galaxy or galaxy-galaxy strong lens systems in the submillimeter bands with high angular resolution. The silhouette of an IMBH in the lensing galaxy halo would appear as either a monopole-like or a dipole-like variation at the scale of the Einstein radius against the Einstein ring of the dust-emitting region surrounding the QSO. We use a particle tagging technique to dynamically populate a M…
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…
16 new quasars at the end of the reionization unveiled by self-supervised learning
Max Planck Institut für Astronomie（马克斯·普朗克天文学研究所）；Pontificia Universidad Católica de Chile（智利天主教 Pontificia 大学）；Universität Heidelberg（海德堡大学）；Millennium Institute of Astrophysics (MAS)（天体物理学千年研究所）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio（意大利国家天体物理研究所空间科学与天体物理观测站）；Instituto de Alta Investigación, Universidad de Tarapacá（塔拉帕卡大学高级研究所）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Universidad Diego Portales（迭戈·波特莱斯大学）
We review the current status of knowledge concerning the early phases of star formation during cosmic dawn. This includes the first generations of stars forming in the lowest mass dark matter halos in which cooling and condensation of gas with primordial composition is possible at very high redshift ($z > 20$), namely metal-free Population III stars, and the first generation of massive black holes forming at such early epochs, the so-called black hole seeds. The formation of black hole seeds as end states of the collapse of Population III stars, or via direct collapse scenarios, is discussed. …
We present measurements of black hole masses and Eddington ratios for a sample of 38 bright (M$_{1450}$ < -24.4 mag) quasars at 5.8 < z < 7.5, derived from VLT/X-shooter near-IR spectroscopy of their broad CIV and MgII emission lines. The black hole masses (on average M$_{BH}$ ~ 4.6 x 10$^9$ M$_{\odot}$) and accretion rates (with Eddington ratios ranging between 0.1 and 1.0) are broadly consistent with that of similarly luminous 0.3 < z < 2.3 quasars, but there is evidence for a mild increase in the median Eddington ratio going towards z > 6. Combined with deep ALMA observations of the [CII] 1…
We report the discovery of a luminous quasar, J1007+2115 at $z=7.515$ ("Pōniuā'ena"), from our wide-field reionization-era quasar survey. J1007+2115 is the second quasar now known at $z>7.5$, deep into the reionization epoch. The quasar is powered by a $(1.5\pm0.2)\times10^9$ $M_{\odot}$ supermassive black hole (SMBH), based on its broad MgII emission-line profile from Gemini and Keck near-IR spectroscopy. The SMBH in J1007+2115 is twice as massive as that in quasar J1342+0928 at $z=7.54$, the current quasar redshift record holder. The existence of such a massive SMBH just 700 million years af…
Hierarchical models of galaxy formation predict that galaxy mergers represent a significant transitional stage of rapid supermassive black hole (SMBH) growth. Yet, the connection between the merging process and enhanced active galactic nuclei (AGN) activity as well as the timescale of SMBH mergers remains highly uncertain. The breakthrough in reconciling the importance of galaxy mergers with black hole growth lies in a thoroughly-studied census of dual AGN across cosmic history, which will be enabled by next-generation observational capabilities, theoretical advances, and simulations. This whi…
We present an estimate of the mass of the supermassive black hole (SMBH) in the nearby type-1 Seyfert galaxy \object{NGC 1097} using Atacamma Large Millimeter/Submillimeter Array (ALMA) observations of dense gas kinematics. Dense molecular gas dynamics are traced with ${\rm HCN} (J=1-0)$ and ${\rm HCO^{+}} (J=1-0)$ emission lines. Assuming a host galaxy inclination of $46^{\circ}$, we derive a SMBH mass, $M_{\rm BH}=1.40^{+0.27}_{-0.32} \times 10^{8}M_{\odot}$, and an I-band mass to light ratio to be $5.14^{+0.03}_{-0.04}$, using ${\rm HCN} (J=1-0)$. The estimated parameters are consistent bet…
Unveiling the properties of galaxy cores excavated by supermassive black hole binaries with SHARP
INAF – Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；INAF – Osservatorio Astronomico d’Abruzzo（意大利国家天体物理研究所阿布鲁佐天文台）；Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova（帕多瓦大学伽利略物理与天文系）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；School of Mathematics and Physics, University of Surrey（萨里大学数理学院）
The Millimeter/X-ray Relation in Rapidly Accreting Supermassive Black Holes at $z < 0.16$
Universidad Diego Portales（迭戈·波特莱斯大学）；University of Geneva（日内瓦大学）；Peking University（北京大学）；Chalmers University of Technology（查尔姆斯理工大学）；Liège Université（列日大学）；Universiteit Gent（根特大学）；Leibniz-Institut für Astrophysik Potsdam (AIP)（波茨坦阿斯特罗物理学会莱布尼茨研究所）；Joint ALMA Observatory（ALMA联合天文台）
A radio source at the Galactic center Sgr A* is a prime supermassive black hole candidate and therefore key to developing our understanding of them. Time variations in the 230 GHz band flux of Sgr A* have been found with the Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 5 observations. Measuring the flux density of Sgr A* in 1 min snapshots at 217.5, 219.5, and 234.0 GHz, we obtained light curves for ten 70 min periods. The light curves show variations at a few tens of minutes and hourly scales. The shorter timescale is similar to the orbital period of the innermost stable circular…
It is well established that a dominant phase in the growth of massive galaxies occurred at high redshift and was heavily obscured by gas and dust. Many studies have explored the stellar growth of massive galaxies but few have combined these constraints with the growth of the supermassive black hole (SMBH; i.e., identified as AGN activity). In this brief contribution we highlight our work aimed at identifying AGNs in z~2 luminous dust-obscured galaxies. Using both sensitive X-ray and infrared (IR)-submillimeter (submm) observations, we show that AGN activity is common in z~2 dust-obscured syste…
We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 3 observations of CO(2-1) emission from the circumnuclear disk in the E/S0 galaxy NGC 1332 at 0.044" resolution. The disk exhibits regular rotational kinematics and central high-velocity emission (+/-500 km/s) consistent with the presence of a compact central mass. We construct models for a thin, dynamically cold disk in the gravitational potential of the host galaxy and black hole, and fit the beam-smeared model line profiles directly to the ALMA data cube. Model fits successfully reproduce the disk kinematics out to r=200 p…
We report a detailed modeling of a mass profile of a $z = 0.2999$ massive elliptical galaxy using 30 milli-arcsecond resolution 1-mm Atacama Large Millimeter/submillimeter Array (ALMA) images of the galaxy-galaxy lensing system SDP.81. The detailed morphology of the lensed multiple images of the $z = 3.042$ infrared-luminous galaxy, which is found to consist of tens of $\lesssim 100$-pc-sized star-forming clumps embedded in a $\sim 2$ kpc disk, are well reproduced by a lensing galaxy modeled by an isothermal ellipsoid with a 400 pc core. The core radius is consistent with that of the visible s…
We present our ongoing work of using two independent tracers to estimate the supermassive black hole mass in the nearby early-type galaxy NGC 6958; namely integrated stellar and molecular gas kinematics. We used data from the Atacama Large Millimeter/submillimeter Array (ALMA), and the adaptive-optics assisted Multi-Unit Spectroscopic Explorer (MUSE) and constructed state-of-the-art dynamical models. The different methods provide black hole masses of $(2.89\pm 2.05) \times 10^8M_{\odot}$ from stellar kinematics and $(1.35\pm 0.09) \times 10^8M_{\odot}$ from molecular gas kinematics which are c…
