We consider the impact of anisotropic radiation on the active galactic nucleus (AGN) radiative dusty feedback. The radiation pattern originating from the accretion disc is determined by the central black hole (BH) spin. Here we analyse how such BH spin-induced angular dependence affects the dynamics and energetics of the radiation pressure-driven outflows, as well as AGN obscuration and BH accretion. In addition, we explore the effect of a spatially varying dust-to-gas ratio on the outflow propagation. We obtain two distinct trends for high-spin and low-spin objects, providing a direct connection between anisotropic feedback and BH spin. In the case of maximum spin, powerful quasi-spherical outflows can propagate on large scales, at all inclination angles with fairly uniform energetics. In contrast, in the case of zero spin, only weaker bipolar outflows can be driven in the polar directions. As a result, high BH spins can efficiently clear out the obscuring gas from most directions, whereas low BH spins can only remove dusty gas from the polar regions, hence also determining the overall AGN obscuration geometry. Due to such anisotropic feedback, high BH spins can prevent accretion of gas from most directions (except in the equatorial plane), while low BH spins allow inflows to proceed from a wider range of directions. This may have important implications for the BH growth in the early Universe. Anisotropic radiative dusty feedback, ruled by the BH spin, may thus play a major role in shaping AGN evolution over cosmic time.
Radiative efficiency in radio-loud AGN is governed by the scaled accretion rate on to the central black hole rather than directly by the type of accreted matter; while it correlates with real physical differences, it does not give us unambiguous information about particular objects.
Radiative efficiency is an important physical parameter that describes the fraction of accretion material converted to radiative energy for accretion onto massive black holes (MBHs). With the simplest Sołtan argument, the radiative efficiency of MBHs can be estimated by matching the mass density of MBHs in the local universe to the accreted mass density by MBHs during AGN/QSO phases. In this paper, we estimate the local MBH mass density through a combination of various determinations of the correlations between the masses of MBHs and the properties of MBH host galaxies, with the distribution f…
The effects of Active Galactic Nuclei (AGNs) on their host-galaxies depend on the coupling between the injected energy and the interstellar medium (ISM). Here, we model and quantify the impact of long-range AGN ionizing radiation -- in addition to the often considered small-scale energy deposition -- on the physical state of the multi-phase ISM of the host-galaxy, and on its total Star Formation Rate (SFR). We formulate an AGN Spectral Energy Distribution matched with observations, which we use with the radiative transfer (RT) code Cloudy to compute AGN ionization in a simulated high-redshift …
Growing observational evidence confirms the existence of massive black holes ($M_{BH} \sim 10^9 M_{\odot}$), accreting at rates close to the Eddington limit, at very high redshifts ($z \gtrsim 6-7$) in the early Universe. Recent observations indicate that the host galaxies of the first quasars are chemically evolved systems, containing unexpectedly large amounts of dust. Such a combination of high luminosities and large dust content should form favourable physical conditions for radiative dusty feedback. We explore the impact of the active galactic nucleus (AGN) feedback, driven by radiation p…
Feedback from the active galactic nuclei (AGN) is one of the most promising heating mechanisms to circumvent the cooling-flow problem in galaxy clusters. However, the role of thermal conduction remains unclear. Previous studies have shown that anisotropic thermal conduction in cluster cool cores (CC) could drive the heat-flux driven buoyancy instabilities (HBI) that re-orient the field lines in the azimuthal directions and isolate the cores from conductive heating from the outskirts. However, how the AGN interacts with the HBI is still unknown. To understand these interwined processes, we perf…
Active galactic nucleus (AGN) feedback, driven by radiation pressure on dust, is an important mechanism for efficiently coupling the accreting black hole to the surrounding environment. Recent observations confirm that X-ray selected AGN samples respect the effective Eddington limit for dusty gas in the plane defined by the observed column density versus the Eddington ratio, the so-called $N_{\rm H} - λ$ plane. A `forbidden' region occurs in this plane, where obscuring clouds cannot be long-lived, due to the action of radiation pressure on dust. Here we compute the effective Eddington limit by…
New populations of hyper-luminous, dust-obscured quasars have been recently discovered around the peak epoch of galaxy formation ($z \sim 2-3$), in addition to similar sources found at lower redshifts. Such dusty quasars are often interpreted as sources `in transition', from dust-enshrouded starbursts to unobscured luminous quasars, along the evolutionary sequence. Here we consider the role of the active galactic nucleus (AGN) radiative feedback, driven by radiation pressure on dust, in high-luminosity, dust-obscured sources. We analyse how the radiation pressure-driven dusty shell models, wit…
An accretion disk in an Active Galactic Nucleus (AGN) harbors and shields dust from external illumination: at the mid-plane of the disk around a $M_{\rm BH}=10^{7}M_{\odot}$ black hole, dust can exist at $0.1$pc from the black hole, compared to 0.5pc outside of the disk. We construct a physical model of a disk region approximately located between the radius of dust sublimation at the disk mid-plane and the radius at which dust sublimes at the disk surface. Our main conclusion is that for a wide range of model parameters such as local accretion rate and/or opacity, the accretion disk's own radi…
Based on two-dimensional high resolution hydrodynamic numerical simulation, we study the mechanical and radiative feedback effects from the central AGN on the cosmological evolution of an isolated elliptical galaxy. Physical processes such as star formation and supernovae are considered. The inner boundary of the simulation domain is carefully chosen so that the fiducial Bondi radius is resolved and the accretion rate of the black hole is determined self-consistently. In analogy to previous works, we assume that the specific angular momentum of the galaxy is low. It is well-known that when the…
Context: Active galactic nuclei (AGN) are anisotropic objects surrounded by an optically thick equatorial medium whose true geometry still defy observers. Aims: In this paper, we aim to explore the optical, scattering-induced, polarization emerging from clumpy and warped dusty tori to check whether they can fit with the unified model predictions. Methods: We run polarized radiative transfer simulations in a set of warped and non warped clumpy tori to explore the differences induced by distorted dust distributions. We then include warped tori in a more complex model representative of an AGN to …
Warm ionized and cold neutral outflows with velocities exceeding $100\,{\rm km\,s}^{-1}$ are commonly observed in galaxies and clusters. Theoretical studies however indicate that ram pressure from a hot wind, driven either by the central active galactic nucleus (AGN) or a starburst, cannot accelerate existing cold gas to such high speeds without destroying it. In this work we explore a different scenario, where cold gas forms in a fast, radiatively cooling outflow with temperature $T\lesssim 10^7\,{\rm K}$. Using 3D hydrodynamic simulations, we demonstrate that cold gas continuously fragments …
Observations point towards a close connection between nuclear starbursts, active galactic nuclei (AGN), and outflow phenomena. An evolutionary sequence, starting from a dust-obscured ultra-luminous infrared galaxy and eventually leading to an unobscured optical quasar, has been proposed and discussed in the literature. AGN feedback is usually invoked to expel the obscuring gas and dust in a blow-out event, but the underlying physical mechanism remains unclear. We consider AGN feedback driven by radiation pressure on dust, which directly acts on the obscuring dusty gas. We obtain that radiative…
The actual mechanism(s) powering galactic outflows in active galactic nuclei (AGN) is still a matter of debate. At least two physical models have been considered in the literature: wind shocks and radiation pressure on dust. Here we provide a first quantitative comparison of the AGN radiative feedback scenario with observations of galactic outflows. We directly compare our radiation pressure-driven shell models with the observational data from the most recent compilation of molecular outflows on galactic scales. We show that the observed dynamics and energetics of galactic outflows can be repr…
We present the results from a broadband (1 to 3 GHz), spectro-polarimetry study of the integrated emission from 100 extragalactic radio sources with the ATCA, selected to be highly linearly polarized at 1.4 GHz. We use a general purpose, polarization model-fitting procedure that describes the Faraday rotation measure (RM) and intrinsic polarization structure of up to three distinct polarized emission regions or 'RM components' of a source. Overall, 37%/52%/11% of sources are best fit by one/two/three RM components. However, these fractions are dependent on the signal-to-noise ratio (S/N) in po…
Active Galactic Nuclei (AGNs) release huge amounts of energy in their host galaxies, which, if the coupling is sufficient, can affect the interstellar medium (ISM). We use a high-resolution simulation ($\sim6$ pc) of a z $\sim2$ star-forming galaxy hosting an AGN, to study this not yet well-understood coupling. In addition to the often considered small-scale thermal energy deposition by the AGN, which is implemented in the simulation, we model long-range photo-ionizing AGN radiation in post-processing, and quantify the impact of AGN feedback on the ability of the gas to form stars. Surprisingl…
AGN radiative feedback as the main regulator of [O III] outflow activity and obscuration in X-ray AGN
Max-Planck-Institut für Extraterrestrische Physik（马克斯·普朗克地外物理研究所）；Excellence Cluster ORIGINS（ORIGINS卓越集群）；School of Physics and Astronomy, Tel Aviv University（特拉维夫大学物理与天文学学院）；INAF-Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；Centre for Extragalactic Astronomy, Department of Physics, Durham University（达勒姆大学物理系河外天文中心）
We explore the gas dynamics near the dust sublimation radius of active galactic nucleus (AGN). For the purpose, we perform axisymmetric radiation hydrodynamic simulations of a dusty gas disk of radius $\approx 1\,\mathrm{pc}$ around a supermassive black hole of mass $10^{7}\,\mathrm{M_{\odot}}$ taking into account (1) anisotropic radiation of accretion disk, (2) X-ray heating by corona, (3) radiative transfer of infrared (IR) photons reemitted by dust, (4) frequency dependency of direct and IR radiations, and (5) separate temperatures for gas and dust. As a result, we find that for Eddington r…
The Fermi Gamma-ray Space Telescope reveals two large bubbles in the Galaxy, which extend nearly symmetrically ~50 degrees above and below the Galactic center (GC). Using three-dimensional (3D) magnetohydrodynamic (MHD) simulations that self-consistently include the dynamical interaction between cosmic rays (CR) and thermal gas, and anisotropic CR diffusion along the magnetic field lines, we show that the key characteristics of the observed gamma-ray bubbles and the spatially-correlated X-ray features in ROSAT 1.5 keV map can be successfully reproduced by a recent jet activity from the central…
We study the moderate-to-high radiative luminosity active galactic nuclei (HLAGN) within the VLA-COSMOS 3 GHz Large Project. The survey covers 2.6 square degrees centered on the COSMOS field with a 1$σ$ sensitivity of 2.3 $\mathrm{μJy}$/beam across the field. This provides the simultaneously largest and deepest radio continuum survey available to date with exquisite multi-wavelength coverage. The survey yields 10,830 radio sources with signal-to-noise ratios $\geq$5. A subsample of 1,604 HLAGN is analyzed here. These were selected via a combination of X-ray luminosity and mid-infrared colors. …
The cosmic history of supermassive black hole (SMBH) growth is important for understanding galaxy evolution, reionization and the physics of accretion. Recent NuSTAR, Swift-BAT and \textit{Chandra} hard X-ray surveys have provided new constraints on the space density of heavily obscured Active Galactic Nuclei (AGN). Using the new X-ray luminosity function derived from these data, we here estimate the accretion efficiency of SMBHs and their contribution to reionization. We calculate the total ionizing radiation from active galactic nuclei (AGN) as a function of redshift, based on the X radiatio…
Feedback from accreting supermassive black holes, active galactic nuclei (AGN), is now a cornerstone of galaxy formation models. In this work, we present radiation-hydrodynamic simulations of radiative AGN feedback using the novel Arepo-RT. A central black hole emits radiation at a constant luminosity and drives an outflow via radiation pressure on dust grains. Utilising an isolated NFW halo we validate our setup in the single and multi-scattering regimes, with the simulated shock front propagation in excellent agreement with the expected analytic result. For a spherically symmetric NFW halo, …
We study the relation between obscuration and supermassive black hole (SMBH) growth using a large sample of hard X-ray selected Active Galactic Nuclei (AGN). We find a strong decrease in the fraction of obscured sources above the Eddington limit for dusty gas ($\log λ_{\rm Edd}\gtrsim -2$) confirming earlier results, and consistent with the radiation-regulated unification model. This also explains the difference in the Eddington ratio distribution functions (ERDFs) of type 1 and type 2 AGN obtained by a recent study. The break in the ERDF of nearby AGN is at $\log λ_{\rm Edd}^{*}=-1.34\pm0.07$…
Cool-Core Destruction in Merging Clusters with AGN Feedback and Radiative Cooling
National Taiwan University（台湾大学）；California Institute of Technology（加州理工学院）；National Tsing Hua University（清华大学）；National Center for Theoretical Sciences（国家理论科学中心）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密松天体物理中心）；University of Modena and Reggio Emilia（摩德纳和雷焦艾米利亚大学）
The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN continuum luminosity, a technique known as reverberation mapping. The IR response is the convolution of the AGN ultraviolet/optical light curve with a transfer function that contains information about the size, geometry, and structure of the torus. Here, we describe a new computer model that simulates the reverberation response of a clumpy torus. Given an input…
We study a sample of 1,604 moderate-to-high radiative luminosity active galactic nuclei (HLAGN) selected at 3 GHz within the VLA-COSMOS 3 GHz Large Project. These were classified by combining multiple AGN diagnostics: X-ray data, mid-infrared data and broad-band spectral energy distribution fitting. We decompose the total radio 1.4 GHz luminosity ($\mathrm{L_{1.4\ GHz,TOT}}$) into the emission originating from star formation and AGN activity by measuring the excess in $\mathrm{L_{1.4\ GHz,TOT}}$ relative to the infrared-radio correlation of star-forming galaxies. To quantify the excess, for ea…
Centres of galaxy clusters must be efficiently reheated to avoid a cooling catastrophe. One potential reheating mechanism is anisotropic thermal conduction, which could transport thermal energy from intermediate radii to the cluster center. However, if fields are not re-randomised, anisotropic thermal conduction drives the heat buoyancy instability (HBI) which reorients magnetic field lines and shuts off radial heat fluxes. We revisit the efficiency of thermal conduction under the influence of spin-driven AGN jets in idealised magneto-hydrodynamical simulations with anisotropic thermal conduct…
We study the obscuring structure of circumnuclear disks (CNDs) by considering supernova (SN) feedbacks from nuclear starburst and the effect of anisotropic radiative pressure from AGNs. We suppose that the mass accretion onto a central supermassive black hole (SMBH) is triggered by SN-driven turbulence within CNDs, and we explore how the structures of CNDs depend on the BH mass ($M_{\rm BH}$) and AGN luminosity ($L_{\rm AGN}$). We find that the obscuring fraction ($f_{\rm obs}$) peaks at $\sim10\%$ of the Eddington luminosity ($L_{\rm Edd}$), and its maximal value is $f_\mathrm{obs} \sim 0.6$ …
Cool outflows are now commonly observed in galaxies, but their physical origin and driving mechanism remain unclear. Active galactic nucleus (AGN) feedback can potentially accelerate cool galactic outflows via cosmic rays (CR) and radiation pressure on dust. Here we investigate the relative importance of CR and radiation feedback in AGNs, and we analyse the physical conditions for outflow launching as a function of the black hole accretion flow mode. We assume CRs from AGN jet origin and consider the analogy with Galactic X-ray binaries, whereby the jet is prominent at low accretion rates (har…
The nuclear obscurer of Active Galactic Nuclei (AGN) is poorly understood in terms of its origin, geometry and dynamics. We investigate whether physically motivated geometries emerging from hydro-radiative simulations can be differentiated with X-ray reflection spectroscopy. For two new geometries, the radiative fountain model of Wada (2012) and a warped disk, we release spectral models produced with the ray tracing code XARS. We contrast these models with spectra of three nearby AGN taken by NuSTAR and Swift/BAT. Along heavily obscured sight-lines, the models present different 4-20keV continu…
To facilitate the study of black hole fueling, star formation, and feedback in galaxies, we outline a method for treating the radial forces on interstellar gas due to absorption of photons by dust grains. The method gives the correct behavior in all of the relevant limits (dominated by the central point source; dominated by the distributed isotropic source; optically thin; optically thick to UV/optical; optically thick to IR) and reasonably interpolates between the limits when necessary. The method is explicitly energy conserving so that UV/optical photons that are absorbed are not lost, but a…
We present an analysis of the spatial distribution of metal-rich gas in ten galaxy clusters using deep observations from the Chandra X-ray Observatory. The brightest cluster galaxies have experienced recent AGN activity in the forms of bright radio emission, cavities, and shock fronts embedded in the hot atmospheres. The heavy elements are distributed anisotropically and are aligned with the large-scale radio and cavity axes. They are apparently being transported from the halo of the brightest cluster galaxy into the intracluster medium along large-scale outflows driven by the radio jets. The …
Understanding how baryonic processes shape the intracluster medium (ICM) is of critical importance to the next generation of galaxy cluster surveys. However, most models of structure formation neglect potentially important physical processes, like anisotropic thermal conduction (ATC). In this letter, we explore the impact of ATC on the prevalence of cool-cores (CCs) using 12 pairs of magnetohydrodynamical galaxy cluster simulations, simulated using the IllustrisTNG model with and without ATC. Although the impact of ATC varies from cluster to cluster and with CC criterion, its inclusion produce…
This paper presents the first measurement of the radio luminosity function of 'jet-mode' (radiatively-inefficient) radio-AGN out to z=1, in order to investigate the cosmic evolution of radio-AGN feedback. Eight radio source samples are combined to produce a catalogue of 211 radio-loud AGN with 0.5<z<1.0, which are spectroscopically classified into jet-mode and radiative-mode (radiatively-efficient) AGN classes. Comparing with large samples of local radio-AGN from the Sloan Digital Sky Survey, the cosmic evolution of the radio luminosity function of each radio-AGN class is independently derived…
Dust emission, an important diagnostic of star formation and ISM mass throughout the Universe, can be powered by sources unrelated to ongoing star formation. In the framework of the DustPedia project we have set out to disentangle the radiation of the ongoing star formation from that of the older stellar populations. This is done through detailed, 3D radiative transfer simulations of face-on spiral galaxies. In this particular study, we focus on NGC 1068, which contains an active galactic nucleus (AGN). The effect of diffuse dust heating by AGN (beyond the torus) was so far only investigated f…
We present the ultraviolet to submillimetre spectral energy distributions (SEDs) of the HERschel Ultra Luminous Infrared Galaxy Survey (HERUS) sample of 42 local ultraluminous infrared galaxies (ULIRGs) and fit them with a Markov chain Monte Carlo (MCMC) code using the CYprus models for Galaxies and their NUclear Spectra (CYGNUS) radiative transfer models for starbursts, active galactic nucleus (AGN) tori and host galaxy. The Spitzer IRS spectroscopy data are included in the fitting. Our bayesian SED fitting method takes comparable time to popular energy balance methods but it is more physical…
Recent observations provide evidence that some cool-core clusters (CCCs) host quasars in their brightest cluster galaxies (BCGs). Motivated by these findings we use 3D radiation-hydrodynamic simulations with the code Enzo to explore the joint role of the kinetic and radiative feedback from supermassive black holes (SMBHs) in BCGs. We implement kinetic feedback as sub-relativistic plasma outflows and model radiative feedback using the ray-tracing radiative transfer or thermal energy injection. In our simulations the central SMBH transitions between the radiatively efficient and radiatively inef…
We have simulated the formation of a massive galaxy cluster (M$_{200}^{\rm crit}$ = 1.1$\times$10$^{15}h^{-1}M_{\odot}$) in a $Λ$CDM universe using 10 different codes (RAMSES, 2 incarnations of AREPO and 7 of GADGET), modeling hydrodynamics with full radiative subgrid physics. These codes include Smoothed-Particle Hydrodynamics (SPH), spanning traditional and advanced SPH schemes, adaptive mesh and moving mesh codes. Our goal is to study the consistency between simulated clusters modeled with different radiative physical implementations - such as cooling, star formation and AGN feedback. We co…
Anisotropic Radiation in Super-Eddington Active Galactic Nuclei: The Responsivity of Broad-Line Regions to Continuum Variability
State Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences（高能物理研究所粒子天体物理国家重点实验室）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）
Using measurements of the [O III], H$α$ and [N II] emission line fluxes originating in the cool (T $\sim10^4$ K) gas that populates the halos of massive early-type galaxies with stellar mass greater than $10^{10.4}$ M$_\odot$, we explore the recent conjecture that active galactic nucleus (AGN) activity preferentially removes the circumgalactic medium (CGM) along the polar (minor-axis) direction. We find deficits in the mean emission line flux of [O III] and H$α$ (65 and 43%, respectively) along the polar vs. planar directions, although due to the large uncertainties in these difficult measurem…
Photoionization modeling of certain low-ionization broad absorption lines in quasars implies very compact (Delta R~0.01 pc), galaxy-scale (R kpc) absorbers blueshifted by several 1000 km s^-1. While these are likely signatures of quasar outflows, the lifetimes of such compact absorbers are too short for them to be direct ejecta from a nuclear wind. Instead, I argue that the absorbing clouds must be transient and created in situ. Following arguments detailed by Faucher-Giguere, Quataert, & Murray (2011), I show that a model in which the cool absorbers form in radiative shocks arising when a qua…
We use a phenomenological model to show that black hole growth in the local Universe (z < 0.1) can be described by two separate, mass independent Eddington ratio distribution functions (ERDFs). We assume that black holes can be divided into two independent groups: those with radiatively efficient accretion, primarily hosted by optically blue and green galaxies, and those with radiatively inefficient accretion, which are mainly found in red galaxies. With observed galaxy stellar mass functions as input, we show that the observed AGN luminosity functions can be reproduced by using mass independe…
We explore the multiwavelength properties of AGN host galaxies for different classes of radio-selected AGN out to z$\lesssim$6 via a multiwavelength analysis of about 7700 radio sources in the COSMOS field. The sources were selected with the Very Large Array (VLA) at 3 GHz (10 cm) within the VLA-COSMOS 3 GHz Large Project, and cross-matched with multiwavelength ancillary data. This is the largest sample of high-redshift (z$\lesssim$6) radio sources with exquisite photometric coverage and redshift measurements available. We constructed a sample of moderate-to-high radiative luminosity AGN (HLAG…
We recently used hydro-chemical simulations to demonstrate that molecular outflows observed in luminous quasars can be explained by molecule formation within the AGN wind. However, these simulations cover a limited parameter space, due to their computational cost. We have therefore developed an analytic model to follow cooling in the shocked ISM layer of an AGN wind. We explore different ambient densities ($1-10^{4} \, \rm{cm}^{-3}$), density profile slopes ($0-1.5$), AGN luminosities ($10^{44}-10^{47} \, \rm{erg} \, \rm{s}^{-1}$), and metallicities ($0.1-3 \rm{Z}_{\odot}$). The swept up gas m…
We present three-dimensional hydrodynamical simulations showing the effect of kinetic and radiative AGN feedback on a model galaxy representing a massive quiescent low-redshift early-type galaxy of $M_* = 8.41\times 10^{10} M_\odot$, harbouring a $M_\mathrm{BH} = 4\times 10^8 M_\odot $ black hole surrounded by a cooling gaseous halo. We show that, for a total baryon fraction of $\sim 20\%$ of the cosmological value, feedback from the AGN can keep the galaxy quiescent for about 4.35 Gyr and with properties consistent with black hole mass and X-ray luminosity scaling relations. However, this can…
We explore the properties of ionized gas in the nuclear and circumnuclear environment of the narrow-line Seyfert 1 galaxy NGC 4051 using spectroscopic and imaging observations from the Hubble Space Telescope (HST) and Apache Point Observatory (APO)'s ARC 3.5m Telescope. We identify an unresolved moderate-density intermediate width component and a high-density broad component in the optical emission lines from the active nucleus, as well as spatially-resolved emission extending up to $\sim$1 kpc in the AGN ionized narrow-line region (NLR) and $\sim$8 kpc in the stellar ionized host galaxy. The …
