Young radio AGN are pivotal for our understanding of many of the still-debated aspects of AGN feedback. In this paper we present a study of the interstellar medium in the compact, peaked-spectrum radio galaxy PKSB1934-63 using X-shooter observations. Most of the warm ionized gas resides within a circum-nuclear disk with a radius of about 200pc that is likely to constitute the gas reservoir from which the central black hole feeds. On the other hand, we find a biconical outflow of warm ionized gas with an estimated radius of 59+/-12pc. This matches the radial extent of the radio source and suggests that the outflow is jet driven. Thanks to the superior wavelength coverage of the data, we can estimate the density of the warm ionized gas using the trans-auroral line technique, and we find that the outflowing gas has remarkably high density, up to n_e~10^5.5cm^-3 . The estimated mass outflow rate is low (M_dot=10^-3 - 10^-1 M_solar/yr) and the AGN feedback operates at relatively low efficiency (E_dot/L_bol~10^-4 - 10^-3 %), in contrast to predictions of theoretical models. In addition, optical and near-IR line ratios show that the expansion of the radio source drives fast shocks (with velocities v>500km/s) that ionize and accelerate the outflowing gas. At odds with the properties of other compact, peaked-spectrum radio sources hosting warm ionized gas outflows, we do not find signs of kinematically disturbed or outflowing gas in phases colder than the warm ionized gas. We argue that this is due to the young age of our source and thus to the recent nature of the AGN-ISM interaction, and suggest that cold gas forms within the outflowing material and the shock-ionized outflowing gas of PKSB1934-63 did not have enough time to cool down, and accumulate in a colder phase. This scenario is also supported by the multi-phase outflows of other compact and young radio sources in the literature.
Outflows from super-massive black holes (SMBHs) play an important role in the co-evolution of themselves, their host galaxies, and the larger scale environments. Such outflows are often characterized by emission and absorption lines in various bands and in a wide velocity range blueshifted from the systematic redshift of the host quasar. In this paper, we report a strong broad line region (BLR) outflow from the z~4.7 quasar BR 1202-0725 based on the high-resolution optical spectrum taken with the Magellan Inamori Kyocera Echelle (MIKE) spectrograph installed on the 6.5m Magellan/Clay telescope…
Probing outflow physics through CH$_3$CN and CH$_3$OH chemistry
INAF, Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所，阿切特里天文台）；University of Victoria（维多利亚大学）；European Southern Observatory（欧洲南方天文台）；Leiden University（莱顿大学）；Max-Planck-Institut für Astronomie (MPIA)（马克斯·普朗克天文学研究所）
A recent hydrodynamic model, "radiation-driven fountain model" (Wada et al. 2016), presented a dynamical picture that active galactic nuclei (AGNs) tori sustain their geometrical thickness by gas circulation around AGNs, and previous papers confirmed that this picture is consistent with multi-wavelength observations of nearby Seyfert galaxies. Recent near-infrared observations implied that CO rovibrational absorption lines ($ΔJ=\pm1$, $v=0-1$, $λ\sim 4.7$ $\mathrm{μm}$) could probe physical properties of the inside tori. However, the origin of the CO absorption lines has been under debate. In …
We present SOFIA/FIFI-LS observations of five prototypical, low-mass Class I outflows (HH111, SVS13, HH26, HH34, HH30) in the far-infrared [OI]63mum and [OI]145mum transitions. The obtained spectroscopic [OI]63mum and [OI]145mum maps enable us to study the spatial extent of warm, low-excitation atomic gas within outflows driven by Class I protostars. These [OI] maps may potentially allow us to measure the mass-loss rates ($\dot{M}_\text{jet}$) of this warm component of the atomic jet.
Probing AGN Feedback in Dwarf Galaxies with Spatially Resolved NIR Coronal Lines from JWST
University of California, Riverside（加州大学河滨分校）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Ehime University（爱媛大学）；George Mason University（乔治梅森大学）；California Institute of Technology（加州理工学院）；Steward Observatory, University of Arizona（亚利桑那大学斯图尔德天文台）；University of California, Los Angeles（加州大学洛杉矶分校）
Probing neutral outflows in z ~ 2 galaxies using JWST observations of Ca II H and K absorption lines
Università di Bologna（博洛尼亚大学）；INAF, Osservatorio di Astrofisica e Scienza dello Spazio（意大利国家天体物理研究所，天文与空间科学观测站）；Swinburne University of Technology（斯威本科技大学）；ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)（ARC三维全天空天体物理学卓越中心（ASTRO 3D））；Center for Astrophysics — Harvard & Smithsonian（哈佛-史密森尼天体物理中心）；The Pennsylvania State University（宾夕法尼亚州立大学）
We examine the kinematics of the gas in the environments of galaxies hosting quasars at $z\sim2$. We employ 148 projected quasar pairs to study the circumgalactic gas of the foreground quasars in absorption. The sample selects foreground quasars with precise redshift measurements, using emission-lines with precision $\lesssim300\,{\rm km\,s^{-1}}$ and average offsets from the systemic redshift $\lesssim|100\,{\rm km\,s^{-1}}|$. We stack the background quasar spectra at the foreground quasar's systemic redshift to study the mean absorption in \ion{C}{2}, \ion{C}{4}, and \ion{Mg}{2}. We find tha…
Dusty quasars might be in a young stage of galaxy evolution with prominent quasar feedback. A recently discovered population of luminous, extremely red quasars at $z\sim$~2--4 has extreme spectral properties related to exceptionally powerful quasar-driven outflows. We present Keck/KCWI observations of the reddest known ERQ, at $z=$\,2.3184, with extremely fast [\ion{O}{III}]~$λ$5007 outflow at $\sim$6000~km~s$^{-1}$. The Ly$α$ halo spans $\sim$100~kpc. The halo is kinematically quiet, with velocity dispersion $\sim$300~km~s$^{-1}$ and no broadening above the dark matter circular velocity down …
We present the first spatially resolved mass outflow rate measurements ($\dot M_{out}$) of the optical emission line gas in the narrow line region (NLR) of a Seyfert 2 galaxy, Markarian 573. Using long slit spectra and [O III] imaging from the Hubble Space Telescope and Apache Point Observatory in conjunction with emission line diagnostics and Cloudy photoionization models, we find a peak outflow rate of $\dot M_{out} \approx$ 3.4 $\pm$ 0.5 $M_{\odot}$ yr$^{-1}$ at a distance of 210 pc from the central supermassive black hole (SMBH). The outflow extends to distances of 600 pc from the nucleus …
Galactic-scale outflows regulate the stellar mass growth and chemical enrichment of galaxies, yet key outflow properties such as the chemical composition and mass loss rate remain largely unknown. We address these properties with Keck/ESI echellete spectra of nine gravitationally lensed z=2-3 star forming galaxies, probing a range of absorption transitions. Interstellar absorption in our sample is dominated by outflowing material, with typical velocities -150 km/s. Approximately 80% of the total column density is associated with a net outflow. Mass loss rates in the low ionization phase are co…
In this paper, we build from previous work (Bustard et al. 2018) and present simulations of recent (within the past Gyr), magnetized, cosmic ray driven outflows from the Large Magellanic Cloud (LMC), including our first attempts to explicitly use the derived star formation history of the LMC to seed outflow generation. We run a parameter set of simulations for different LMC gas masses and cosmic ray transport treatments, and we make preliminary comparisons to published outflow flux estimates, neutral and ionized hydrogen observations, and Faraday rotation measure maps. We additionally report o…
We use Gemini Near-Infrared Integral Field Spectrograph (NIFS) observations of the inner 3.5$\times$3.5 kpc$^2$ of the radio galaxy Cygnus A to map the gas excitation and kinematics at a spatial resolution of 200 pc. The emission of the ionised gas shows a biconical morphology, with half-opening angle of 45$^\circ$ and oriented along the position angle of the radio jet. Coronal line emission is seen within the cone, up to 1.75 kpc from the nucleus, with higher ionisation gas observed in the easterly side. The H$_2$ and [Fe II] emission lines are consistent with excitation by the central AGN, w…
The complex structure of gas, metals, and dust in the interstellar and circumgalactic medium (ISM and CGM, respectively) in star-forming galaxies can be probed by Ly$α$ emission and absorption, low-ionization interstellar (LIS) metal absorption, and dust reddening E(B-V). We present a statistical analysis of the mutual correlations among Ly$α$ equivalent width (EW$_{Lyα}$), LIS equivalent width (EW$_{LIS}$), and E(B-V) in a sample of 157 star-forming galaxies at $z\sim2.3$. With measurements obtained from individual, deep rest-UV spectra and spectral-energy distribution (SED) modeling, we find…
Observations of UV metal absorption lines have provided insight into the structure and composition of the circumgalactic medium (CGM) around galaxies. We compare these observations with the low-redshift ($z \leq 0.3$) CGM around dwarf galaxies in high-resolution cosmological zoom-in runs in the FIRE-2 simulation suite. We select simulated galaxies that match the halo mass, stellar mass, and redshift of the observed samples. We produce absorption measurements using Trident for UV transitions of C IV, O VI, Mg II and Si III. The FIRE equivalent width (EW) distributions and covering fractions for…
The MUSE Ultra Deep Field (MUDF) VIII. The cool gas distribution surrounding galaxies at redshifts z ~ 0.5-2
Università degli Studi di Milano-Bicocca（米兰比可卡大学）；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）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；IUCAA（印度联合大学宇宙学及应用天文学中心）；INAF – Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；Space Telescope Science Institute（太空望远镜科学研究所）；Johns Hopkins University（约翰斯·霍普金斯大学）
利用MUDF调查的深MUSE数据，研究红移0.5 < z < 2星系周围低温气体分布，通过径向和横向分析探讨气体出流与星系际介质特性。
We study the interstellar medium in a sample of 27 high-redshift quasar host galaxies at z>6, using the [CII] 158um emission line and the underlying dust continuum observed at ~1kpc resolution with ALMA. By performing uv-plane spectral stacking of both the high and low spatial resolution data, we investigate the spatial and velocity extent of gas, and the size of the dust-emitting regions. We find that the average surface brightness profile of both the [CII] and the dust continuum emission can be described by a steep component within a radius of 2kpc, and a shallower component with a scale len…
Active Galactic Nuclei (AGN) display complex X-ray spectra which exhibit a variety of emission and absorption features, that are commonly interpreted as a combination of i) a relativistically smeared reflection component, resulting from the irradiation of an accretion disk by a compact hard X-ray source, ii) one or several warm/ionized absorption components produced by AGN-driven outflows crossing our line of sight, and iii) a non relativistic reflection component produced by more distant material. Disentangling these components via detailed model fitting can thus be used to constrain the blac…
The characterization of the large amount of gas residing in the galaxy halos, the so called circumgalactic medium (CGM), is crucial to understand galaxy evolution across cosmic time. We focus here on the the cool ($T\sim10^4$ K) phase of this medium around star-forming galaxies in the local universe, whose properties and dynamics are poorly understood. We developed semi-analytical parametric models to describe the cool CGM as an outflow of gas clouds from the central galaxy, as a result of supernova explosions in the disc (galactic wind). The cloud motion is driven by the galaxy gravitational …
We present an overview of the ALMA chemical survey of disk-outflow sources in Taurus (ALMA-DOT), a campaign devoted to the characterization of the molecular emission from partly embedded, young stars. The project aims at better understanding the gaseous products that are delivered to planets by means of high-resolution maps of assorted lines probing disks at the time of the planet formation (less than 1 Myr). Nine different molecules are surveyed by our observations of six Class I/flat-spectrum sources. A series of accompanying articles analyze specific targets and molecules. Here we describe …
Probing the Metal Enrichment of the Intergalactic Medium at $z=5-6$ Using the Hubble Space Telescope
我们使用哈勃太空望远镜（HST）ACS斜坡窄带滤波器探测$z=5$ -6上四个强星系际CIV吸收体的关联星系，检验星系外流模型。四种强CIV吸收剂位于$z=5.74$、$5.52$、$4.95$和$4.87$，柱密度范围为$N_{\rm{CIV}}=10^{13.8}$ cm $^{-2}$至$10^{14.8}$ cm $^{-2}$。在$z=5.74$，我们检测到一个i-dropout Ly $α$发射体（LAE）候选者，其预计影响参数为42物理kpc，来自CIV吸收体。该LAE候选物的基于Ly $α$的恒星形成率（SFR $_{\rm{Lyα}}$）为2 $M_\odot$ yr $^{-1}$，基于UV的SFR为4 $M_\odot$ yr $^{-1}$。虽然我们不能完全排除这个$i$ -dropout发射体可能是一个[OII]闯入者，但它的测量特性与$z=5.74$的CIV动力星系一致。对于CIV吸收体在$z=4.95$和$z=4.87$，虽然我们检测到两个LAE候选人的影响参数为160 kpc和200 kpc，这样的距离大于从模拟预测。因此，我们将其视为未检测。对于在$z=5.52$的系统，我们没有检测到LAE候选，将SFR $_{\rm{Lyα}}\approx 1.5\ M_\odot$ yr $^{-1}$的3- $σ$上限。总之，在这4例病例中，我们仅在$z=…
We present a sample of 34 weak metal line absorbers at $z< 0.3$ complied via the simultaneous detections ($3σ$) of the SiII$\lambda1260$ and CII$\lambda1334$ absorption lines, with $W_{r}$(SiII)$<0.2$ Å and $W_{r}$(CII)$<0.3$ Å, in archival HST/COS spectra. Our sample increases the number of known low-$z$ "weak absorbers" by a factor of $>5$. The column densities of HI and low-ionization metal lines obtained from Voigt profile fitting are used to build simple photoionization models using CLOUDY. The inferred densities and total hydrogen column densities are in the ranges of $-3.3 < \log n_{\rm…
Observational searches for intermediate-mass black holes (IMBHs; $10^2 - 10^6$ $M_\odot$) include relatively isolated dwarf galaxies. For those that host active galactic nuclei (AGNs), the IMBH nature may be discerned through the accretion - jet activity. We present radio observations of four AGN-hosting dwarf galaxies (which potentially harbor IMBHs). Very large array (VLA) observations indicate steep spectra (indices of $-$0.63 to $-$1.05) between 1.4 and 9 GHz. A comparison with the 9 GHz in-band spectral index however shows a steepening for GH047 and GH158 (implying older/relic emission) a…
Submillimetre and millimetre observations are important in probing the properties of the molecular gas and dust around obscured active galactic nuclei (AGNs) and their feedback. With very high-resolution (0."02x0."03 (2x3 pc)) ALMA 345 GHz observations of CO 3-2, HCO$^+$ 4-3, HCN 4-3 $ν_2$=1$f$, and continuum we have studied the molecular outflow and nucleus of the extremely radio-quiet lenticular galaxy NGC1377. The outflow is resolved, revealing a 150 pc long, clumpy, high-velocity, collimated molecular jet. The molecular emission is emerging from the spine of the jet with an average diamete…
We present RadioAstron Space VLBI imaging observations of the BL Lac object S5 0716+71 made on January 3-4 2015 at a frequency of 22 GHz (wavelength $λ=1.3$ cm). The observations were made in the framework of the AGN Polarization Key Science Program. The source was detected on projected space-ground baselines up to 70 833 km (5.6 Earth diameters) for both, parallel hand and cross-hand interferometric visibilities. We have used these detections to obtain a full-polarimetric image of the blazar at an unprecedented angular resolution of 24 $μ$as, the highest for this source to date. This enabled …
Energy Partition in AGN-driven Bubbles of NGC 4438: From Nuclear Bubbles to a Galaxy-scale Outflow
Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；Department of Astronomy, University of Science and Technology of China（中国科学技术大学天文系）；School of Astronomy and Space Science, University of Science and Technology of China（中国科学技术大学天文与空间科学学院）；Hamburger Sternwarte, Universität Hamburg（汉堡天文台，汉堡大学）；Xiangtan University（湘潭大学）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Department of Astronomy, University of Massachusetts, Amherst（马萨诸塞大学阿默斯特分校天文学系）
本研究以 NGC 4438 为对象，通过多波段分析明确 AGN 驱动气泡的能量分配随尺度的变化，发现小尺度核区气泡与大尺度外流的喷流功率关联存在差异，揭示了 AGN 反馈的尺度依赖性。
