ALMACAL X: Constraints on molecular gas in the low-redshift circumgalactic medium
arXiv:2304.12421 · doi:10.1093/mnrasl/slad053
Abstract
Despite its crucial role in galaxy evolution, the complex circumgalactic medium (CGM) remains underexplored. Although it is known to be multi-phase, the importance of the molecular gas phase to the total CGM mass budget is, to date, unconstrained. We present the first constraints on the molecular gas covering fraction in the CGM of low-redshift galaxies, using measurements of CO column densities along sightlines towards mm-bright background quasars with intervening galaxies. We do not detect molecular absorption against the background quasars. For the individual, low-redshift, 'normal' galaxy haloes probed here, we can therefore rule out the presence of an extremely molecular gas-rich CGM, as recently reported in high-redshift protoclusters and around luminous active galactic nuclei. We also set statistical limits on the volume filling factor of molecular material in the CGM as a whole, and as a function of radius. ISM-like molecular clouds of ~30 pc in radius with column densities of N(CO) >~ 10^16 cm^-2 have volume filling factors of less than 0.2 per cent. Large-scale smooth gas reservoirs are ruled out much more stringently. The development of this technique in the future will allow deeper constraining limits to be set on the importance (or unimportance) of molecular gas in the CGM.
arXiv comment5 pages, 5 figures, accepted for publication in MNRAS
References in corpus (36)
- The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
- The SIMBAD astronomical database
- The Circumgalactic Medium
- astroquery: An Astronomical Web-Querying Package in Python
- The Large, Oxygen-Rich Halos of Star-Forming Galaxies Are A Major Reservoir of Galactic Metals
- The Baryon Census in a Multiphase Intergalactic Medium: 30% of the Baryons May Still Be Missing
- How to Calculate Molecular Column Density
- The Cosmic Baryon and Metal Cycles
- Ultraviolet Survey of CO and H_2 in Diffuse Molecular Clouds: The Reflection of Two Photochemistry Regimes in Abundance Relationships
- Figuring Out Gas & Galaxies in Enzo (FOGGIE). I. Resolving Simulated Circumgalactic Absorption at 2 < z < 2.5
- Distances to Galactic high-velocity clouds. I. Cohen Stream, complex GCP, cloud g1
- Properties of the Circumgalactic Medium in Cosmic Ray-Dominated Galaxy Halos
- The Hidden Mass and Large Spatial Extent of a Poststarburst Galaxy Outflow
- Effect of environment on galaxies mass-size distribution: unveiling the transition from outside-in to inside-out evolution
- Virialization of the inner CGM in the FIRE simulations and implications for galaxy discs, star formation and feedback
- A Universal Density Structure for Circum-Galactic Gas
- Molecular Gas in the Halo Fuels the Growth of a Massive Cluster Galaxy at High Redshift
- The effect of magnetic fields on properties of the circumgalactic medium
- ALMACAL IV: A catalogue of ALMA calibrator continuum observations
- Multi-phase Circum-Galactic Medium probed with MUSE and ALMA
- A FUSE Survey of Molecular Hydrogen in Intermediate-Velocity Clouds in the Milky Way Halo
- Molecular gas on large circumgalactic scales at z=3.47
- Discovery of molecular hydrogen in a high-velocity cloud of the Galactic halo
- The COSMOS-UltraVISTA stellar-to-halo mass relationship: new insights on galaxy formation efficiency out to
- An HST/COS survey of molecular hydrogen in DLAs & sub-DLAs at z < 1: Molecular fraction and excitation temperature
- Cosmic alignment towards the radio Einstein ring PKS 1830-211 ?
- ALMACAL VI: Molecular gas mass density across cosmic time via a blind search for intervening molecular absorbers
- SUPER. VI. A giant molecular halo around a z~2 quasar
- Emission from the circumgalactic medium: from cosmological zoom-in simulations to multiwavelength observables
- The cold circumgalactic environment of MAMMOTH-I: dynamically cold gas in the core of an Enormous Ly-alpha Nebula
- Feeding the spider with carbon -- [CII] emission from the circum galactic medium and active galactic nucleus
- MUSE-ALMA Halos VI: Coupling Atomic, Ionised & Molecular Gas Kinematics of Galaxies
- ALMA Observations of Molecular Absorption in the Gravitational Lens PMN 0134-0931
- Evidence for extended gaseous reservoirs around AGN at cosmic noon from ALMA CO(3-2) observations
- A detection of H in a high velocity cloud toward the Large Magellanic Cloud
- H_2 molecular gas absorption-selected systems trace CO molecular gas-rich galaxy overdensities