Linked evolution of gas and star formation in galaxies over cosmic history

Abstract

We compare the cosmic evolution of star formation rates in galaxies with that of their neutral hydrogen densities. We highlight the need for neutral hydrogen to be continually replenished from a reservoir of ionized gas to maintain the observed star formation rates in galaxies. Hydrodynamic simulations indicate that the replenishment may occur naturally through gas infall, although measured rates of gas infall in nearby galaxies are insufficient to match consumption. We identify an alternative mechanism for this replenishment, associated with expanding supershells within galaxies. Pre-existing ionized gas can cool and recombine efficiently in the walls of supershells, molecular gas can form in situ in shell walls, and shells can compress pre-existing molecular clouds to trigger collapse and star formation. We show that this mechanism provides replenishment rates sufficient to maintain both the observed HI mass density and the inferred molecular gas mass density over the redshift range 0<z<5.

5 pages, 2 figures, accepted by ApJ Letters

References in corpus (13)

• Cold gas accretion in galaxies
• The star formation histories of galaxies in the Sloan Digital Sky Survey
• Science With The Australian Square Kilometre Array Pathfinder
• From the warm magnetized atomic medium to molecular clouds
• The Evolution of Stellar Mass and the Implied Star Formation History
• Bursting and Quenching in Massive Galaxies without Major Mergers or AGNs
• A Model for Star Formation, Gas Flows and Chemical Evolution in Galaxies at High Redshifts
• The HI content of star-forming galaxies at z = 0.24
• The Source of Ionization along the Magellanic Stream
• Searching for Low Surface-brightness Galaxies in the Hubble Ultra Deep Field: Implications for the Star Formation Efficiency in Neutral Gas at z ~ 3
• Where is the Molecular Hydrogen in Damped Lyman-Alpha Absorbers?
• The star formation rate of CaII and damped Lyman-alpha absorbers at 0.4<z<1.3
• The "Carina Flare" Supershell: Probing the Atomic and Molecular ISM in a Galactic Chimney

Cited by in corpus (18)

• Gas accretion from minor mergers in local spiral galaxies
• Galaxy And Mass Assembly (GAMA): Gas Fuelling of Spiral Galaxies in the Local Universe I. - The Effect of the Group Environment on Star Formation in Spiral Galaxies
• Cloudy with A Chance of Rain: Accretion Braking of Cold Clouds
• X-ray emission from the nuclear region of Arp 220
• Galaxy And Mass Assembly (GAMA): Timescales for galaxies crossing the green valley
• Revealing the Ionization Properties of the Magellanic Stream using Optical Emission
• Coevolution of metallicity and star formation in galaxies to z=3.7: II. A theoretical model
• Fountain-driven gas accretion feeding star formation over the disc of NGC 2403
• Simulating Gas Inflow at the Disk-Halo Interface
• The Complete Local Volume Groups Sample -- IV. Star formation and gas content in group-dominant galaxies
• The Bluedisk Survey: molecular gas distribution and scaling relations in the context of galaxy evolution
• An Expanding Neutral Hydrogen Supershell Evacuated by Multiple Supernovae in M101
• Proximate molecular quasar absorbers: Chemical enrichment and kinematics of the neutral gas
• Testing the Radio-Selection Method of Dual Active Galactic Nuclei in the Stripe 82 Field
• Neural Infalling Cloud Equations (NICE): Increasing the Efficacy of Subgrid Models and Scientific Equation Discovery using Neural ODEs and Symbolic Regression
• Measuring Cosmic Density of Neutral Hydrogen via Stacking the DINGO-VLA Data
• Simulating High-Velocity Clouds in the Observational Plane: An Initial Study with the Smith Cloud
• Stellar Abundances at the Center of Early Type Galaxies with Fine Structure