We study the mass assembly and spin evolution of supermassive black holes (BHs) across cosmic time as well as the impact of gravitational recoil on the population of nuclear and wandering black holes (wBHs) by using the semi-analytical model LGalaxies run on top of Millennium merger trees. We track spin changes that BHs experience during both coalescence events and gas accretion phases. For the latter, we assume that spin changes are coupled with the bulge assembly. This assumption leads to predictions for the median spin values of z=0 BHs that depend on whether they are hosted by pseudobulges, classical bulges or ellipticals, being a ~ 0.9, 0.7 and 0.4, respectively. The outcomes of the model display a good consistency with z<4 quasar luminosity functions and the z=0 BH mass function, spin values and black hole-bulge mass correlation. Regarding the wBHs, we assume that they can originate from both the disruption of satellite galaxies (orphan wBH) and ejections due to gravitational recoils (ejected wBH). The model points to a number density of wBHs that increases with decreasing redshift, although this population is always ~2 dex smaller than the one of nuclear black holes. At all redshifts, wBHs are typically hosted in M_{halo}>10^{13} M_{\odot} and M_{stellar}>10^{10} M_{\odot}, being orphan wBHs the dominant type. Besides, independently of redshift and halo mass, \textit{ejected} wBHs inhabit the central regions (<0.3R_{200}) of the host DM halo, while orphan wBHs linger at larger scales (>0.5R_{200}). Finally, we find that gravitational recoils cause a progressive depletion of nuclear BHs with decreasing redshift and stellar mass. Moreover, ejection events lead to changes in the predicted local black hole-bulge relation, in particular for BHs in pseudobulges, for which the relation is flattened at M_{bulge}>10^{10.2} M{\odot} and the scatter increase up to ~3dex.
Though smooth, extended spheroidal stellar outskirts have long been observed around nearby dwarf galaxies, it is unclear whether dwarfs generically host an extended stellar halo. We use imaging from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) to measure the shapes of dwarf galaxies out to four effective radii for a sample of dwarfs at 0.005<z<0.2 and 10^7<M_star/M_sun<10^9.6. We find that dwarfs are slightly triaxial, with a <B/A> >~ 0.75 (where the ellipsoid is characterized by three principle semi-axes constrained by C<=B<=A). At M_star>10^8.5 M_sun, the galaxies grow from thick…
We present the first metal abundance profiles for a representative sample of massive clusters. Our measures extend to $R_{500}$ and are corrected for a systematic error plaguing previous outskirt estimates. Our profiles flatten out at large radii, admittedly not a new result, however the radial range and representative nature of our sample extends its import well beyond previous findings. We find no evidence of segregation between cool-core and non-cool-core systems beyond $\sim 0.3 R_{500}$, implying that, as was found for thermodynamic properties (Ghirardini et al, 2019), the physical state …
We present results from deep and very spatially extended CTIO/DECam $g$ and $r$ photometry (reaching out to $\sim$ 2 mag below the oldest MSTO and covering $\sim$ 20 deg$^2$) around the Sextans dSph. We use this data-set to study the structural properties of Sextans overall stellar population and its different stellar evolutionary phases, as well as to search for signs of tidal disturbance from the MW, which would indicate departure from dynamical equilibrium. We perform the most accurate structural analysis to-date of Sextans' stellar components by applying Bayesian MCMC methods to the indivi…
VST-SMASH: VST Survey of Mass Assembly and Structural Hierarchy I. Survey presentation and deep photometry of IC 5332: tracing the mass assembly in the challenging faintest-end regime
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）；INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）；Sterrenkundig Observatorium, Universiteit Gent（根特大学天文台）；Department of Astronomy, Indiana University（印第安纳大学天文学系）；INAF - Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天文空间科学观测站）；Università di Salerno（萨莱诺大学）；INFN – Gruppo Collegato di Salerno – Sezione di Napoli（意大利国家核物理研究所萨莱诺协作组那不勒斯分部）；Department of Physics and Astronomy, University of Padua（帕多瓦大学物理与天文学系）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）
The 31 brightest galaxies (m_B < 15 mag) inside the virial radius of the Fornax cluster were observed from the centres to the outskirts with the Multi Unit Spectroscopic Explorer on the Very Large Telescope. These observations provide detailed high-resolution maps of the line-of-sight kinematics and line strengths of the stars and ionised gas reaching 2-3 Re for 21 early-type galaxies and 1-2 Re for 10 late-type galaxies. The majority of the galaxies are regular rotators, with eight hosting a kinematically distinct core. Only two galaxies are slow rotators. The mean age, total metallicity, and…
The outskirts of galaxies have been studied from multiple perspectives for the past few decades. However, it is still unknown if all galaxies have clear-cut edges like everyday objects. We address this question by developing physically motivated criteria to define the edges of galaxies. Based on the gas density threshold required for star formation, we define the edge of a galaxy as the outermost radial location associated with a significant drop in either past or ongoing in-situ star formation. We explore $\sim$1000 low-inclination galaxies with a wide range in morphology (dwarfs to elliptica…
We present analysis on three intervening H I-C IV absorption systems tracing gas within galaxy group/cluster environments, identified in the $HST$/COS far-UV spectra of the background quasars PG $1148+549$ ($z_{abs}=0.00346$), SBS~$1122+594$ ($z_{abs}=0.00402$) and RXJ~$1230.8+0115$ ($z_{abs}=0.00574$). The ionization models are consistent with the origin of metal lines and H I from a cool and diffuse photoionized gas phase with $T \lesssim 4 \times 10^{4}$ K and $n_{\mathrm{H}} \lesssim 5 \times 10^{-4}$ cm$^{-3}$. The three absorbers have $89$, $51$ and $17$ galaxies detected within $1$ Mpc …
Ams: We study the 12C/13C isotopic ratio in the disk of the central molecular zone and in the halo to trace gas accretion toward the Galactic center region in the Milky Way. Methods: Using the IRAM 30m telescope, we observe the J=1-0 rotational transition of HCO+, HCN, HNC and their 13C isotopic substitutions in order to measure the 12C/13C isotopic ratio. We observe 9 positions selected throughout the Galactic center region, including clouds at high latitude; locations where the X1 and X2 orbits associated with the barred potential are expected to intersect; and typical Galactic center molecu…
Upcoming wide-field surveys are well-suited to studying the growth of galaxy clusters by tracing galaxy and gas accretion along cosmic filaments. We use hydrodynamic simulations of volumes surrounding 324 clusters from \textsc{The ThreeHundred} project to develop a framework for identifying and characterising these filamentary structures, and associating galaxies with them. We define 3-dimensional reference filament networks reaching $5R_{200}$ based on the underlying gas distribution and quantify their recovery using mock galaxy samples mimicking observations such as those of the WEAVE Wide-F…
Recent evidence of extremely metal-rich stars found in the Sombrero galaxy (M104) halo suggests that this galaxy has undergone a recent major merger with a relatively massive galaxy. In this paper, we present wide-field deep images of the M104 outskirts obtained with a 18-cm amateur telescope with the purpose of detecting any coherent tidal features from this possible major merger. Our new data, together with a model of the M104 inner halo and scattered light from stars around the field, allow us to trace for the first time the full path of the stream on both sides of the disk of the galaxy. W…
We study the evolution of baryonic gas in cosmologically growing dark matter halos. To accurately model both the inner and outer regions of the halos, we use a dark matter density profile that transitions smoothly from the NFW profile within the virial radius to a more realistic flat profile far beyond the halo. We construct a dark matter gravitational potential consistent with this density profile, and we use a "cosmological" potential that accounts for gas evolution consistent with Hubble expansion at large radii. Gas is initialized with a density $\approx$ 0.2 times the dark matter density,…
The Infrared Glow of Galactic Outskirts: A New Window with NASIM
University of Southampton（南安普顿大学）；Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Universidad de La Laguna（拉古纳大学）；Centro de Estudios de Física del Cosmos de Aragón (CEFCA)（阿拉贡宇宙物理研究中心）；INAF-Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；IFPU, Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）
NASIM 是一种自动化近红外处理管线，用于恢复 VISTA 数据中的低表面亮度结构，其表面亮度极限比 2MASS 深 67 倍，为研究星系外围和微弱宇宙提供了新窗口。
For type-1 active galactic nuclei (AGNs) for which the equatorial scattering is the dominant broad line polarization mechanism, it is possible to measure the supermassive black hole mass by tracing the Keplerian motion across the polarization plane positionangle. So far this method has been used for 30 objects but only for H$α$ emission line. We explore the possibilities this method for determining SMBH masses using polarization in broad emission lines by applying it for the first time to Mg II$λ$2798AA spectral line. We use 3D Monte Carlo radiative transfer code stokes for simultaneous modeli…
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…
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…
The large-scale overdensities of galaxies at z~2-7 known as protoclusters are believed to be the sites of cluster formation, and deep, wide survey projects such as the Large Synoptic Survey Telescope (LSST) and the Wide Field Infrared Survey Telescope (WFIRST) will deliver significant numbers of these interesting structures. Spectroscopic confirmation and interpretation of these targets, however, is still challenging, and will require wide-field multi-plexed spectroscopy on >20 m-class telescopes in the optical and near-infrared. In the coming decade, detailed studies of protoclusters will ena…
We present the first fully relativistic prediction of the electromagnetic emission from the surrounding gas of a supermassive binary black hole system approaching merger. Using a ray-tracing code to post-process data from a general relativistic 3-d MHD simulation, we generate images and spectra, and analyze the viewing angle dependence of the light emitted. When the accretion rate is relatively high, the circumbinary disk, accretion streams, and mini-disks combine to emit light in the UV/EUV bands. We posit a thermal Compton hard X-ray spectrum for coronal emission; at high accretion rates, it…
We study the link between supermassive black hole growth and the stellar mass assembly of their host galaxies in the state-of-the-art Romulus suite of simulations. The cosmological simulations Romulus25 and RomulusC employ innovative recipes for the seeding, accretion, and dynamics of black holes in the field and cluster environments respectively. We find that the black hole accretion rate traces the star formation rate among star-forming galaxies. This result holds for stellar masses between 10^8 and 10^12 solar masses, with a very weak dependence on host halo mass or redshift. The inferred r…
Supermassive Black Hole Winds in X-rays: SUBWAYS IV. Tracing Radio Emission and Unveiling the Role of Winds
Università di Bologna（博洛尼亚大学）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）；INAF – Istituto di Astrofisica e Planetologia Spaziali（意大利国家天体物理研究所天体物理学和行星科学研究所）；INAF - Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天体物理学与空间科学观测站）；ASTRON, the Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）；Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡普坦天文研究所）；Technion（以色列理工学院）；Tor Vergata Universi（托尔维尔加塔大学）
Models of galaxy formation in a cosmological context predict that massive disk galaxies should have structured extended stellar halos. Recent studies in integrated light, however, report a few galaxies, including the nearby disk galaxy M101, that have no measurable stellar halos to the detection limit. We aim to quantify the stellar content and structure of M101's outskirts by resolving its stars. We present the photometry of its stars based on deep F606W and F814W images taken with Hubble Space Telescope as part of the GHOSTS survey. The constructed CMDs of stars reach down to two magnitudes …
Recycled Gas Dominates the Metal-rich Fuel of Supermassive Black Holes
University of Seoul（首尔大学）；Flatiron Institute（平托研究所）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理研究所）；Ecole Polytechnique Fédérale de Lausanne（洛桑联邦理工学院）；Sejong University（世宗大学）；Seoul National University（首尔国立大学）
Tracing Galaxy Bias Through the Cosmic Web: The Role of Filaments
Universidad Técnica Federico Santa María（弗雷德里克·Santa Maria 技术大学）；Pontificia Universidad Católica de Valparaíso（瓦爾帕萊索天主教大學）；The University of Tokyo（東京大學）；University of Pennsylvania（賓夕法尼亞大學）；The Abdus Salam International Center for Theoretical Physics（阿卜杜斯·薩拉姆國際理論物理中心）；Universidad Nacional de Córdoba（科爾多瓦國立大學）；CONICET-UNC（阿根廷國家科學技術研究委員會-科爾多瓦大學）
Here we present a short overview and main results of our investigations of several effects which can induce shifts in the broad Fe K$α$ line emitted from relativistic accretion disks around single and binary supermassive black holes. We used numerical simulations based on ray-tracing method in the Kerr metric to study the role of classical Doppler shift, special relativistic transverse Doppler shift and Doppler beaming, general relativistic gravitational redshift, and perturbations of the disk emissivity in the formation of the observed Fe K$α$ line profiles. Besides, we also investigated whet…
Recent observations have shown that a large portion of the mid--infrared (MIR) spectrum of active galactic nuclei (AGN) stems from the polar regions. In this paper, we investigate the effects of this polar gas on the X-ray spectrum of AGN using ray-tracing simulations. Two geometries for the polar gas are considered, (1) a hollow cone corresponding to the best fit MIR model and (2) a filled cone, both with varying column densities (ranging from $10^{21}-10^{22.5}$ cm$^{-2}$) along with a torus surrounding the central X-ray source. We find that the polar gas leads to an increase in the equivale…
Tracing the star formation history in circumnuclear regions (CNRs) is a key step towards understanding the starburst-AGN connection. However, bright nuclei outshining the entire host galaxy prevent the analysis of the stellar populations of CNRs around type-I AGNs. Obscuration of the nuclei by the central torus provides an unique opportunity to study the stellar populations of AGN host galaxies. We assemble a sample of 10, 848 type-II AGNs with a redshift range of $0.03\le z\le 0.08$ from the Sloan Digital Sky Survey's Data Release 4, and measure the mean specific star formation rates (SSFRs) …
Galaxy clusters undergo mergers that can generate extended radio sources called radio relics. Radio relics are the consequence of merger-induced shocks that propagate in the intra cluster medium (ICM). In this paper we analyse the radio, optical and X-ray data from a candidate galaxy cluster that has been selected from the radio emission coming from a candidate radio relic detected in NRAO VLA Sky Survey (NVSS). Our aim is to clarify the nature of this source and prove that under certain conditions radio emission from radio relics can be used to trace relatively low-mass galaxy clusters. We ha…
X-ray cavities are key tracers of mechanical (or radio mode) heating arising from the active galactic nuclei (AGN) in brightest cluster galaxies. We report on a survey for X-ray cavities in 83 massive, high-redshift (0.4<z<1.2) clusters of galaxies selected by their Sunyaev-Zel'dovich signature in the South Pole Telescope data. Based on Chandra X-ray images, we find a total of 6 clusters having symmetric pairs of surface brightness depressions consistent with the picture of radio jets inflating X-ray cavities in the intracluster medium. The majority of these detections are of relatively low si…
Recent X-ray observations have revealed remarkable correlations between the masses of central supermassive black holes (SMBHs) and the X-ray properties of the hot atmospheres permeating their host galaxies, thereby indicating the crucial role of the atmospheric gas in tracing SMBH growth in the high-mass regime. We examine this topic theoretically using the IllustrisTNG cosmological simulations and provide insights to the nature of this SMBH -- gaseous halo connection. By carrying out a mock X-ray analysis for a mass-selected sample of TNG100 simulated galaxies at $z=0$, we inspect the relatio…
Tracing small-scale structure formation through cosmic time with strong gravitational lensing: A case for a next-generation sub-millimetre/millimetre interferometer
European Southern Observatory (ESO)（欧洲南方天文台）；Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡普坦天文研究所）；South African Radio Astronomy Observatory (SARAO)（南非射电天文观测台）；Department of Physics, University of Pretoria（比勒陀利亚大学物理系）；Pole Scientific, Catholic University of Lyon（里昂天主教大学科学部门）；Instituto de Física y Astronomía, Universidad de Valparaíso（瓦尔帕莱索大学物理与天文学研究所）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；Department of Physics, University of Oxford（牛津大学物理系）；Observatoire de Paris, LUX, Collège de France, CNRS, PSL University, Sorbonne University（巴黎天文台，卢克斯，法兰西公学院，法国国家科学研究中心，巴黎文理研究大学，索邦大学）；Dipartimento di Fisica e Astronomia Augusto Righi , Università di Bologna（博洛尼大学奥古斯托·里吉物理与天文学系）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚空间科学与天文学观测台）；INFN – Sezione di Bologna（意大利国家核物理研究所博洛尼亚分部）
FLAMINGO: Tracing the co-evolution of hot gas and black holes in galaxy groups and clusters
Astrophysics Research Institute, Liverpool John Moores University（利物浦约翰摩尔斯大学天体物理研究所）；Institute for Computational Cosmology, Department of Physics, University of Durham（杜伦大学物理学院计算宇宙学研究所）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Lorentz Institute for Theoretical Physics, Leiden University（莱顿大学洛伦兹理论物理研究所）
Tracing the Cosmic web across Cosmic time through SKA observations of radio galaxies
National Centre for Nuclear Research（国家核研究中心）；University of Tartu（塔尔图大学）；Assam Don Bosco University（阿萨姆唐博斯科大学）；Observatoire de Paris（巴黎天文台）；Collège de France（法兰西公学院）；PSL University（PSL大学）；Sorbonne University（索邦大学）
We show the significance of the super-Eddington accretion for the cosmic growth of supermassive black holes (SMBHs) with a semi-analytical model for galaxy and black hole evolution. The model explains various observed properties of galaxies and active galactic nuclei at a wide redshift range. By tracing the growth history of individual SMBHs, we find that the fraction of the SMBH mass acquired during the super-Eddington accretion phases to the total SMBH mass becomes larger for less massive black holes and at higher redshift. Even at z = 0, SMBHs with > 1e+9 Msun have acquired more than 50% of…
BAQARO: Tracing Stochastic Black Hole Growth Histories and Quasar Lightcurves in a Cosmological Context
Center for Astrophysics | Harvard & Smithsonian（天体物理中心 | 哈佛与史密森尼学会）；Leiden Observatory, Leiden University（莱顿天文台，莱顿大学）；Department of Physics, University of California, Santa Barbara（加州大学圣塔芭芭拉分校物理系）
We carry out a comprehensive Bayesian correlation analysis between hot halos and direct masses of supermassive black holes (SMBHs), by retrieving the X-ray plasma properties (temperature, luminosity, density, pressure, masses) over galactic to cluster scales for 85 diverse systems. We find new key scalings, with the tightest relation being the $M_\bullet-T_{\rm x}$, followed by $M_\bullet-L_{\rm x}$. The tighter scatter (down to 0.2 dex) and stronger correlation coefficient of all the X-ray halo scalings compared with the optical counterparts (as the $M_\bullet-σ_{\rm e}$) suggest that plasma …
In 2019, the Event Horizon Telescope Collaboration (EHTC) has published the first image of a supermassive black hole (SMBH) obtained via the Very Large Baseline Interferometry (VLBI) technique. In the future, it is expected that additional and more sensitive VLBI observations will be pursued for other nearby Active Galactic Nuclei (AGN), and it is therefore important to understand which possible features can be expected in such images. In this paper, we post-process General Relativistic Magneto-Hydrodynamical (GR-MHD) simulations which include resistivity, thus providing a self-consistent jet …
Recent stellar population analysis of early-type galaxy spectra has demonstrated that the low-mass galaxies in cluster centers have high [$α/\rm Fe$] and old ages characteristic of massive galaxies and unlike the low-mass galaxy population in the outskirts of clusters and fields. This phenomenon has been termed "coordinated assembly" to highlight the fact that the building blocks of massive cluster central galaxies are drawn from a special subset of the overall low-mass galaxy population. Here we explore this idea in the IllustrisTNG simulations, particularly the TNG300 run, in order to unders…
The direct collapse model of supermassive black hole seed formation provides an attractive solution to the origin of the quasars now routinely observed at $z \gtrsim 6$. We use the adaptive mesh refinement code Enzo to simulate the collapse of gas at high redshift, including a nine species chemical model of H, He, and H$_2$. The direct collapse model requires that the gas cools predominantly via atomic hydrogen. To this end we simulate the effect of an anisotropic radiation source on the collapse of a halo at high redshift. The radiation source is placed at a distance of 3 kpc (physical) from …
We examine the effects of SMBH feedback on the CGM using a cosmological hydrodynamic simulation \citep[{\sc Romulus25};][]{Tremmel2017} and a set of four zoom-in `genetically modified' Milky Way-mass galaxies sampling different evolutionary paths. By tracing the distribution of metals in the circumgalactic medium (CGM), we show that \ion{O}{6} is a sensitive indicator of supermassive black hole (SMBH) feedback. First, we calculate the column densities of \ion{O}{6} in simulated Milky Way-mass galaxies and compare them with observations from the COS-Halos Survey. Our simulations show column den…
Hunting the first Cosmic Giants: formation and detectability of Direct Collapse Black Holes around high-redshift quasars
University of Edinburgh（爱丁堡大学）；Università degli Studi dell’Insubria（因苏布利亚大学）；INAF/Osservatorio Astronomico di Roma（罗马天文台国家 Astrophysics 研究所）；INFN, Sezione di Milano-Bicocca（米兰比可卡大学 INFN 分部）；Institute of Science and Technology Austria (ISTA)（奥地利科学与理工学院）；Columbia University（哥伦比亚大学）；Institut d’Astrophysique de Paris, Sorbonne Université（巴黎天体物理研究所，索邦大学）
We investigate the consequences of superkicks on the population of supermassive black holes (SMBHs) in the Universe residing in brightest cluster galaxies (BCGs). There is strong observational evidence that BCGs grew prominently at late times (up to a factor 2-4 in mass from z=1), mainly through mergers with satellite galaxies from the cluster, and they are known to host the most massive SMBHs ever observed. Those SMBHs are also expected to grow hierarchically, experiencing a series of mergers with other SMBHs brought in by merging satellites. Because of the net linear momentum taken away from…
