We present the detection of [CII] 158um emission from the Spiderweb galaxy at z=2.1612 using the Atacama Pathfinder EXperiment. The line profile splits into an active galactic nucleus (AGN) and circum galacic medium (CGM) component previously identified in CO and [CI]. We find that these individual [CII] components are consistent in terms of CO and far-IR luminosity ratios with the populations of other z>~1 AGN and dusty star-forming galaxies. The CGM component dominates the [CII] emission in the 10" APEX beam. Although we do not have spatially resolved data, the close correspondence of the velocity profile with the CO(1-0) detected only on scales of tens of kiloparsecs in CO(1-0) suggests that the [CII] emission is similarly extended, reminiscent of [CII] halos recently found around z>5 galaxies. Comparing the first four ionization states of carbon, we find that the atomic [CI] emission is dominant, which increases its reliability as a molecular mass tracer. Our [CII] detection at 601.8 GHz also demonstrates the feasibility to extend the frequency range of ALMA Band 9 beyond the original specifications.
The circumgalactic medium (CGM) of the massive Spiderweb Galaxy, a conglomerate of merging proto-cluster galaxies at z=2.2, forms an enriched interface where feedback and recycling act on accreted gas. This is shown by observations of [CI], CO(1-0) and CO(4-3) performed with the Atacama Large Millimeter Array (ALMA) and Australia Telescope Compact Array (ATCA). [CI] and CO(4-3) are detected across ~50 kpc, following the distribution of previously detected low-surface-brightness CO(1-0) across the CGM. This confirms our previous results on the presence of a cold molecular halo. The central radi…
A [CII]-158-micron Survey of DLA galaxies at z~4: Observations of Dense and Metal-Enriched Neutral Gas within the Circumgalactic Medium of Star-Forming Galaxies
We present ALMA observations of a merging system at z ~ 4.57, observed as a part of the ALMA Large Program to INvestigate [CII] at Early times (ALPINE) survey. Combining ALMA [CII] 158 micron and far-infrared continuum data with multi-wavelength ancillary data we find that the system is composed of two massive (Mstar >~ 10^10 Msun) star-forming galaxies experiencing a major merger (stellar mass ratio r_mass ~ 0.9) at close spatial (~13 kpc; projected) and velocity (delta_v < 300 km/s) separations, and two additional faint narrow [CII]-emitting satellites. The overall system belongs to a larger…
We study the efficiency of galactic feedback in the early Universe by stacking the [C II] 158 um emission in a large sample of normal star-forming galaxies at 4 < z < 6 from the ALMA Large Program to INvestigate [C II] at Early times (ALPINE) survey. Searching for typical signatures of outflows in the high-velocity tails of the stacked [C II] profile, we observe (i) deviations from a single-component Gaussian model in the combined residuals and (ii) broad emission in the stacked [C II] spectrum, with velocities of |v|<~ 500 km/s. The significance of these features increases when stacking the s…
Deep observations have detected extended Ly$α$ emission nebulae surrounding tens of quasars at redshift 2 to 6. However, the metallicity of such extended haloes is still poorly understood. We perform a detailed analysis on a large sample of 80 quasars at $z\sim3$ based on MUSE-VLT data. We find clear evidence of extended emission of the UV nebular lines such as CIV or HeII for about 20$\%$ of the sample, while CIII] is only marginally detected in a few objects. By stacking the cubes we detect emission of CIV, HeII and CIII] out to a radius of about 45 kpc. CIV and HeII show a radial decline mu…
We investigate the morphology of the [CII] emission in a sample of "normal" star-forming galaxies at $5<z<7.2$ in relation to their UV (rest-frame) counterpart. We use new ALMA observations of galaxies at $z\sim6-7$ as well as a careful re-analysis of archival ALMA data. In total 29 galaxies were analysed, 21 of which are detected in [CII]. For several of the latter the [CII] emission breaks into multiple components. Only a fraction of these [CII] components, if any, is associated with the primary UV systems, while the bulk of the [CII] emission is associated either with fainter UV components,…
Widespread Extended [CII] Emission in High-Redshift Galaxies: Insights from the FIRE-2 Cosmological Zoom-in Simulations
California Institute of Technology（加州理工学院）；CIERA and Department of Physics and Astronomy, Northwestern University（西北大学 CIERA 与物理和天文系）；IPAC, California Institute of Technology（加州理工学院 IPAC）；Department of Physics and Astronomy, University of Pennsylvania（宾夕法尼亚大学物理和天文系）
We survey the incidence and absorption strength of the metal-line transitions CII 1334 and CIV from the circumgalactic medium (CGM) surrounding z~2 quasars, which act as signposts for massive dark matter halos M_halo~10^12.5 Msun. On scales of the virial radius (Mvir~160kpc), we measure a high covering fraction fC=0.73+/-0.10 to strong CII absorption (rest equivalent width W1334>0.2A), implying a massive reservoir of cool (T~10^4K) metal enriched gas. We conservatively estimate a metal mass exceeding 10^8 Msun. We propose these metals trace enrichment of the incipient intragroup/intracluster m…
We present an analytic model for the cool, $T \approx 10^4$ K, circumgalactic medium (CGM), describing the gas distribution, thermal and ionization state. Our model assumes (total) pressure equilibrium with the ambient warm/hot CGM, photoionization by the metagalactic radiation field, and allows for non-thermal pressure support, parametrized by the ratio of thermal pressures, $η= P_{\rm hot,th}/P_{\rm cool,th}$. We apply the model to the COS-Halos data set and find that a nominal model with $η= 3$, gas distribution out to $r \approx 0.6 R_{\rm vir}$, and $M_{\rm cool} = 3 \times 10^9~{\rm M_{\…
NGC 1097 is a nearby Seyfert 1 galaxy with a bright circumnuclear starburst ring, a strong large-scale bar and an active nucleus. We present a detailed study of the spatial variation of the far infrared (FIR) [CII]158um and [OI]63um lines and mid-infrared H2 emission lines as tracers of gas cooling, and of the polycyclic aromatic hydrocarbon (PAH) bands as tracers of the photoelectric heating, using Herschel-PACS, and Spitzer-IRS infrared spectral maps. We focus on the nucleus and the ring, and two star forming regions (Enuc N and Enuc S). We estimated a photoelectric gas heating efficiency ([…
The relationship between a galaxy's properties and its circumgalactic medium (CGM) provides a unique view of how galaxies evolve. We present an interesting edge-on (i=86 degrees) disk galaxy (G1547) where the CGM is probed by a background quasar at a distance of 84 kpc and within 10 degrees of the galaxy major axis. G1547 does not have any detectable CGM absorption down to stringent limits, covering HI (EW$_r$<0.02A, log(N(HI)/cm$^{-2}$)<12.6) and a range of low and high ionisation absorption lines (OI, CII, NII, SiII, CIII, NIII, SiIII, CIV, SiIV, NV and OVI). This system is rare, given the c…
Extended [CII] gas emission in and around a massive quiescent galaxy at z=7.3
Cosmic Dawn Center (DAWN)（宇宙黎明中心）；DTU Space, Technical University of Denmark（丹麦技术大学空间研究所）；Department of Astronomy, University of Geneva（日内瓦大学天文学系）；Center for Astrophysics, Harvard & Smithsonian（哈佛与史密森尼天体物理中心）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体物理学系）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯玻尔研究所）；DARK, Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯玻尔研究所DARK中心）；Department of Physics and Astronomy and PITTPACC, University of Pittsburgh（匹兹堡大学物理与天文系及PITTPACC）
The Multiphase CGM in the Epoch of Reionization: CII and CIV absorbers around [OIII] Emitters
University of Trieste（的里雅斯特大学）；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）；IFPU - Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；Dipartimento di Fisica “Enrico Fermi”, Università di Pisa（比萨大学恩里科·费米物理系）；IUCAA（印度联合大学天体物理中心）；Università degli Studi di Milano-Bicocca（米兰比可卡大学）；Max-Planck-Institut für Ex
Motivated by integral field units (IFUs) on large ground telescopes and proposals for ultraviolet-sensitive space telescopes to probe circumgalactic medium (CGM) emission, we survey the most promising emission lines and how such observations can inform our understanding of the CGM and its relation to galaxy formation. We tie our emission estimates to both HST/COS absorption measurements of ions around $z\approx 0.2$ Milky Way mass halos and models for the density and temperature of gas. We also provide formulas that simplify extending our estimates to other samples and physical scenarios. We f…
We present new results on the kinematics and spatial distribution of metal-enriched gas within 125 kpc (physical) of Lyman Break galaxies at redshifts z~2-3. In particular, we demonstrate how rest-UV galaxy spectra can be used to obtain key spatial and spectral information more efficiently than possible with QSO sightlines. After recalibrating the measurement of galaxy systemic redshifts from their UV spectra, we investigate the kinematics of galaxy-scale outflows via the strong interstellar (IS) absorption and Lya emission lines (when present), as well as their dependence on other physical pr…
The circumgalactic medium (CGM) remains one of the least constrained components of galaxies and as such has significant potential for advancing galaxy formation theories. In this work, we vary the extragalactic ultraviolet background for a high-resolution cosmological simulation of a Milky Way-like galaxy and examine the effect on the absorption and emission properties of metals in the CGM. We find that a reduced quasar background brings the column density predictions into better agreement with recent data. Similarly, when the observationally derived physical properties of the gas are compared…
We characterize the physical properties of the cool T ~10^4 K circumgalactic medium surrounding z ~2-3 quasar host galaxies, which are predicted to evolve into present day massive ellipticals. Using a statistical sample of 14 quasar pairs with projected separation < 300 kpc and high dispersion, high S/N spectra, we find extreme kinematics with low metal ion lines typically spanning ~ 500 km/s, exceeding any previously studied galactic population. The CGM is significantly enriched, even beyond the virial radius, with a median metallicity [M/H] ~ -0.6. The alpha/Fe abundance ratio is enhanced, s…
We study the nature of the low-redshift CGM in the Simba cosmological simulations as traced by ultraviolet absorption lines around galaxies in bins of stellar mass ($M_\star>10^{10}M_\odot$) for star-forming, green valley and quenched galaxies at impact parameters $r_\perp\leq 1.25r_{200}$. We generate synthetic spectra for HI, MgII, CII, SiIII, CIV, and OVI, fit Voigt profiles to obtain line properties, and estimate the density, temperature, and metallicity of the absorbing gas. We find that CGM absorbers are most abundant around star forming galaxies with $M_\star < 10^{11}M_\odot$, while th…
We explore the impact of cosmic rays (CRs) on cosmological adaptive-mesh refinement simulations of a forming 10^12 Msolar halo, focusing on the circumgalactic medium (CGM), and its resulting low-redshift structure and composition. In contrast to a run with star formation and energetic feedback but no CRs, the CR-inclusive runs feature a CGM substantially enriched with CRs and with metals to roughly 0.1 Zsolar, thanks to robust, persistent outflows from the disk. The CR-inclusive CGMs also feature more diffuse gas at lower temperatures, down to 10^4 K, than the non-CR run, with diffuse material…
Active galactic nuclei (AGN) are thought to play a critical role in shaping galaxies, but their effect on the circumgalactic medium (CGM) is not well studied. We present results from the COS-AGN survey: 19 quasar sightlines that probe the CGM of 20 optically-selected AGN host galaxies with impact parameters $80 < ρ_{imp} < 300$ kpc. Absorption lines from a variety of species are measured and compared to a stellar mass and impact parameter matched sample of sightlines through non-AGN galaxies. Amongst the observed species in the COS-AGN sample (HI, CII, SiII, SiIII, CIV, SiIV, NV), only Ly$α$ s…
To characterize the absorption properties of this circumgalactic medium (CGM) and its relation to the LG we present the so-far largest survey of metal absorption in Galactic high-velocity clouds (HVCs) using archival ultraviolet (UV) spectra of extragalactic background sources. The UV data are obtained with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST) and are supplemented by 21 cm radio observations of neutral hydrogen. Along 270 sightlines we measure metal absorption in the lines of SiII, SiIII, CII, and CIV and associated HI 21 cm emission in HVCs in the vel…
The properties of molecular gas, the fuel that forms stars, inside the cavity of the circumnuclear disk (CND) are not well constrained. We present results of a velocity-resolved submillimeter scan (~480 to 1250 GHz}) and [CII]158um line observations carried out with Herschel/HIFI toward Sgr A*; these results are complemented by a ~2'x2' CO (J=3-2) map taken with the IRAM 30 m telescope at ~7'' resolution. We report the presence of high positive-velocity emission (up to about +300 km/s) detected in the wings of CO J=5-4 to 10-9 lines. This wing component is also seen in H2O (1_{1,0}-1_{0,1}) a …
The angular resolution (~10") achieved by the Herschel Space Observatory ~3.5m telescope at FIR wavelengths allowed us to roughly separate the emission toward the inner parsec of the galaxy (the central cavity) from that of the surrounding circumnuclear disk (the CND). The FIR spectrum toward SgrA* is dominated by intense [Oiii], [Oi], [Cii], [Niii], [Nii], and [Ci] fine-structure lines (in decreasing order of luminosity) arising in gas irradiated by the strong UV field from the central stellar cluster. The high-J CO rotational line intensities observed at the interface between the inner CND a…
Disc galaxies like the Milky Way are expected to be surrounded by massive coronae of hot plasma that may contain a significant fraction of the so-called missing baryons. We investigate whether the local (|vLSR|<400 km/s) warm-hot absorption features observed towards extra-Galactic sources or halo stars are consistent with being produced by the cooling of the Milky Way's corona. In our scheme, cooling occurs at the interface between the disc and the corona and it is triggered by positive supernova feedback. We combine hydrodynamical simulations with a dynamical 3D model of the galactic fountain…
The birth of the intracluster medium: the evolution of multiphase gas and Lyman-$α$ haloes in a simulated $z\sim3$ protocluster
University of Nottingham（诺丁汉大学）；The University of Texas at Dallas（德克萨斯大学达拉斯分校）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；University of Cambridge（剑桥大学）
