Observations of emission lines in Active Galactic Nuclei (AGN) often find fast (~1000 km s^-1) outflows extending to kiloparsec scales, seen in ionised, neutral atomic and molecular gas. In this work we present radiative transfer calculations of emission lines in hydrodynamic simulations of AGN outflows driven by a hot wind bubble, including non-equilibrium chemistry, to explore how these lines trace the physical properties of the multiphase outflow. We find that the hot bubble compresses the line-emitting gas, resulting in higher pressures than in the ambient ISM or that would be produced by the AGN radiation pressure. This implies that observed emission line ratios such as [OIV] 25 $μ$m / [NeII] 12 $μ$m , [NeV] 14 $μ$m / [NeII] 12 $μ$m and [NIII] 57 $μ$m / [NII] 122 $μ$m constrain the presence of the bubble and hence the outflow driving mechanism. However, the line-emitting gas is under-pressurised compared to the hot bubble itself, and much of the line emission arises from gas that is out of pressure, thermal and/or chemical equilibrium. Our results thus suggest that assuming equilibrium conditions, as commonly done in AGN line emission models, is not justified if a hot wind bubble is present. We also find that >50 per cent of the mass outflow rate, momentum flux and kinetic energy flux of the outflow are traced by lines such as [NII] 122 $μ$m and [NeIII] 15 $μ$m (produced in the 10^4 K phase) and [CII] 158 $μ$m (produced in the transition from 10^4 K to 100 K).
To investigate the origins of S0 galaxies, we present a new method of analyzing their stellar kinematics from discrete tracers such as planetary nebulae. This method involves binning the data in the radial direction so as to extract the most general possible non-parametric kinematic profiles, and using a maximum likelihood fit within each bin in order to make full use of the information in the discrete kinematic tracers. Both disk and spheroid kinematic components are fitted, with a two-dimensional decomposition of imaging data used to attribute to each tracer a probability of membership in th…
We propose a novel method to constrain turbulence and bulk motions in massive galaxies, groups and clusters, exploring both simulations and observations. As emerged in the recent picture of the top-down multiphase condensation, the hot gaseous halos are tightly linked to all other phases in terms of cospatiality and thermodynamics. While hot halos (10^7 K) are perturbed by subsonic turbulence, warm (10^4 K) ionized and neutral filaments condense out of the turbulent eddies. The peaks condense into cold molecular clouds (< 100 K) raining in the core via chaotic cold accretion (CCA). We show all…
Quasar absorption-line studies in the ultraviolet (UV) can uniquely probe the nature of the multiphase cool-warm (10^4 < T < 10^6 K) gas in and around galaxy clusters, promising to provide unprecedented insights into 1) interactions between the circumgalactic medium (CGM) associated with infalling galaxies and the hot (T > 10^6 K) X-ray emitting intracluster medium (ICM), 2) the stripping of metal-rich gas from the CGM, and 3) a multiphase structure of the ICM with a wide range of temperatures and metallicities. In this work, we present results from a high-resolution simulation of a ~10^14 sol…
The physics of magnetic fields ($\textbf{B}$) and cosmic rays (CRs) have recently been included in simulations of galaxy formation. However, significant uncertainties remain in how these components affect galaxy evolution. To understand their common observational tracers, we analyze the magnetic fields in a set of high-resolution, magneto-hydrodynamic, cosmological simulations of Milky-Way-like galaxies from the FIRE-2 project. We compare mock observables of magnetic field tracers for simulations with and without CRs to observations of Zeeman splitting and rotation/dispersion measures. We find…
Mass outflow rates and loading factors are typically used to infer the quenching potential of galactic-scale outflows. However, these generally rely on observations of a single gas phase which can severely underestimate the total ejected gas mass. To address this, we use observations of high mass ($\geqslant$10$^{10}$ M$_{\odot}$), normal star-forming galaxies at $z\sim$0 from the MaNGA, xCOLD GASS, xGASS and ALFALFA surveys and a stacking of NaD, H$α$, CO(1-0) and HI 21cm tracers with the aim of placing constraints on an average, total mass outflow rate and loading factor. We find detections …
The atomic multiphase interstellar medium of galaxies in the COLIBRE simulations
University of Vienna（维也纳大学）；Leiden University（莱顿大学）；Università degli Studi di Milano-Bicocca（米兰比可卡大学）；University of Durham（杜伦大学）；University of Hull（赫尔大学）；University of Hertfordshire（赫特福德大学）
Ram pressure stripping of the multiphase ISM is studied in the perturbed Virgo cluster spiral galaxy NGC 4438. This galaxy underwent a tidal interaction ~100 Myr ago and is now strongly affected by ram pressure stripping. Deep VLA radio continuum observations at 6 and 20 cm are presented. We detect prominent extraplanar emission to the west of the galactic center, which extends twice as far as the other tracers of extraplanar material. The spectral index of the extraplanar emission does not steepen with increasing distance from the galaxy. This implies in situ re-acceleration of relativistic e…
The radio frequency 1.4 GHz transition of the atomic hydrogen is one of the important tracers of the diffuse neutral interstellar medium. Radio astronomical observations of this transition, using either a single dish telescope or an array interferometer, reveal different properties of the interstellar medium. Such observations are particularly useful to study the multiphase nature and turbulence in the interstellar gas. Observations with multiple radio telescopes have recently been used to study these two closely related aspects in greater detail. Using various observational techniques, the de…
Much progress has been made recently in the acceleration of $\sim10^{4}$\,K clouds to explain absorption-line measurements of the circumgalactic medium and the warm, atomic phase of galactic winds. However, the origin of the cold, molecular phase in galactic winds has received relatively little theoretical attention. Studies of the survival of $\sim10^{4}$\,K clouds suggest efficient radiative cooling may enable the survival of expelled material from galactic disks. Alternatively, gas colder than 10$^4$\,K may form within the outflow, including molecules if dust survives the acceleration proce…
Multiphase turbulence as the origin of OH+, H2O+ and H3+ column density scatter in the local ISM
Technion Israel Institute of Technology（以色列理工学院）；The Johns Hopkins University（约翰斯·霍普金斯大学）；Rutgers, The State University of New Jersey（新泽西州立罗格斯大学）；Center for Computational Astrophysics, Flatiron Institute, Simons Foundation（西蒙斯基金会平顿研究所计算天体物理学中心）
Multiphase Gas Structure in the Circumnuclear Region of NGC 5506 Observed with ALMA
International Christian University（国际基督教大学）；National Astronomical Observatory of Japan（日本国立天文台）；The Graduate University for Advanced Studies, SOKENDAI（高级研究院）；National Institute of Technology, Kure College（国立高等专门学校吴工业高等专门学校）；Kagoshima University（鹿儿岛大学）；Kogakuin University of Technology & Engineering（工學館大學）
Massive dusty multiphase outflow in local merger shows no sign of slowing on kiloparsec scales
Institute of Theoretical Astrophysics, University of Oslo（奥斯陆大学理论天体物理研究所）；Armagh Observatory and Planetarium（阿马天文台和天文馆）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；Dipartimento di Fisica e Astronomia Augusto Righi, Università degli Studi di Bologna（博洛尼亚大学奥古斯托·里基物理与天文学系）；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体物理学观测站）
Context. Massive star-formation leads to enrichment with heavy elements of the interstellar medium. On the other hand, the abundance of heavy elements is a key parameter to study the star-formation history of galaxies. Furthermore, the total molecular hydrogen mass, usually determined by converting CO or [C ii] 158 $μ$m luminosities, depends on the metallicity as well. The excitation of metallicity-sensitive emission lines, however, depends on the gas density of H ii regions, where they arise. Aims. We used spectroscopic observations from SOFIA, Herschel, and Spitzer of the nuclear region of t…
Observations of $z \gtrsim 6$ quasars provide information on the early phases of the most massive black holes (MBHs) and galaxies. Current observations at sub-mm wavelengths trace cold and warm gas, and future observations will extend information to other gas phases and the stellar properties. The goal of this study is to examine the gas life cycle in a $z \gtrsim 6$ quasar: from accretion from the halo to the galaxy and all the way into the MBH, to how star formation and the MBH itself affect the gas properties. Using a very-high resolution cosmological zoom-in simulation of a $z=7$ quasar in…
Surveying the Whirlpool at Arcseconds with NOEMA (SWAN). IV. Extent of active galactic nucleus feedback on the interstellar medium
Universität Bonn（波恩大学）；Observatorio Astronómico Nacional (IGN)（国家天文台（西班牙地理与测绘研究所））；The Ohio State University（俄亥俄州立大学）；Center for Cosmology and Astro-Particle Physics, Ohio State University（俄亥俄州立大学宇宙学与天体粒子物理中心）；National Astronomical Observatory of Japan（日本国立天文台）；Max Planck Institute for Radio Astronomy（马克斯·普朗克射电天文研究所）；University of Arkansas（阿肯色大学）
Faraday tomography of a field centred on the extragalactic point source 3C 196 with the LOw Frequency ARray (LOFAR) revealed an intertwined structure of diffuse polarised emission with straight depolarisation canals and tracers of the magnetized and multi-phase interstellar medium (ISM), such as dust and line emission from atomic hydrogen (HI). This study aims at extending the multi-tracer analysis of LOFAR data to three additional fields in the surroundings of the 3C 196 field. For the first time, we study the three-dimensional structure of the LOFAR emission by determining the distance to th…
Multiple molecular lines are useful for studying the physical properties of multiphase star-forming gas in different types of galaxies. We probe the molecular gas throughout the disc of the spiral galaxy NGC~5033, hosting an active galactic nucleus (AGN), using multiple low-$J$ CO lines [$^{12}$CO(1-0, 2-1, 3-2 and $^{13}$CO(1-0, 2-1)] and dense gas tracers [HCN(1-0) and HCO$^{+}$(1-0)]. Firstly, we determine the ratios of the integrated intensity maps and the ratio of intensities in position velocity diagrams. Secondly, we obtain the ratios of CO lines and high-density tracers at the centre; …
Star formation depends critically on cooling mechanisms in the interstellar medium (ISM); however, thermal properties of gas in galaxies at the peak epoch of star formation (z ~ 2) remain poorly understood. A limiting factor in understanding the multiphase ISM is the lack of multiple tracers detected in the same galaxies, such as Polycyclic Aromatic Hydrocarbon (PAH) emission, a tracer of a critical photoelectric heating mechanism in interstellar gas, and [C II] 158μm fine-structure emission, a principal coolant. We present ALMA Band 9 observations targeting [C II] in six z ~ 2 star-forming ga…
Imprints of the Neutral Interstellar Medium on Polarized Synchrotron Emission and Faraday Rotation
Stanford University（斯坦福大学）；University of South Carolina（南卡罗来纳大学）；Observatoire de Paris, Université PSL, Sorbonne Université, CNRS（巴黎天文台，巴黎文理研究大学，索邦大学，法国国家科学研究中心）；Laboratoire de Physique de l’École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, Observatoire de Paris（巴黎高等师范学院物理实验室，ENS，巴黎文理研究大学，法国国家科学研究中心，索邦大学，巴黎西岱大学，巴黎天文台）；INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所 - 阿切特里天文台）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Research School of Astronomy & Astrophysics, The Australian National University（澳大利亚国立大学天文学与天体物理学研究学院）；Dunlap Institute for Astronomy and Astrophysics, University of Toronto（多伦多大学邓普勒天文学与天体物理研究所）
Tracing gas outflows in molecular gas-rich galaxies with the SKA
University Catholic of Lyon- University of Lyon（里昂天主教大学-里昂大学）；Indian Institute of Astrophysics（印度天体物理研究所）；Amity University Uttar Pradesh（阿美提北方邦大学）；National Centre for Radio Astrophysics - Tata Institute of Fundamental Research（国家射电天体物理学中心-塔塔基础研究所）；Indian Institute of Science（印度科学学院）
JWST resolves jet-driven H2 and ionized outflows in radio galaxy 3C305
Space Telescope Science Institute（太空望远镜科学研究所）；CNRS, Institut d’Astrophysique de Paris（法国国家科学研究中心，巴黎天体物理学研究所）；The College of New Jersey（新泽西学院）；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）；Instituto de Astrofísica de La Plata (CONICET–UNLP)（拉普拉塔天体物理研究所（阿根廷国家科学研究委员会-拉普拉塔国立大学））；Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata（拉普拉塔国立大学天文与地球科学学院）；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体物理观测台）；National Radio Astronomy Observatory (Associated Universities, Inc.)（美国国家射电天文台）；Observatorio Astronómico Nacional (IGN)（西班牙国家天文台（隶属于国家地理研究所））；Department of Physics and Astronomy, University of Sheffield（谢菲尔德大学物理与天文学系）
Fine-structure Line Atlas for Multi-wavelength Extragalactic Study (FLAMES) I: Comprehensive Low and High Redshift Catalogs and Empirical Relations for Probing Gas Conditions
Aims: The large abundances of CH$^+$ in the diffuse interstellar medium (ISM) are a long standing issue of our understanding of the thermodynamical and chemical states of the gas. We investigate, here, the formation of CH+ in turbulent and multiphase environments, where the heating of the gas is almost solely driven by the photoelectric effect. Methods: The diffuse ISM is simulated using the magnetohydrodynamic (MHD) code RAMSES which self-consistently computes the dynamical and thermal evolution of the gas along with the time-dependent evolutions of the abundances of H$^+$, H, and H$_2$. The …
