Centrally Concentrated H I Distribution Enhances Star Formation in Galaxies

Abstract

We use a sample of 13,511 nearby galaxies from the ALFALFA and SDSS spectroscopic surveys to study the relation between the spatial distribution of H I 21 cm emission and star formation rate (SFR). We introduce a new non-parametric quantity $K$, measured from the curve-of-growth of the line, to describe the shape of the integrated H I profile. The value of $K$ increases from double-horned to single-peaked profiles, depending on projection effects and the spatial and velocity distribution of the gas. Using carefully chosen samples to control for the competing factors that influence the integrated line profile, we argue that useful inferences can be made on the spatial distribution of the gas. We find that galaxies with a high value of $K$ tend to have more centrally concentrated H I distribution within the optical disk of the galaxy at fixed conditions, and that larger values of $K$ are associated with higher levels of total and central SFR. The results suggest that the global concentration of H I plays an important role in facilitating the conversion of neutral atomic hydrogen to molecular hydrogen gas, which, in turn, affects the star formation activity throughout the optical disk. Our sample is biased against quiescent galaxies, and thus the conclusions may not hold for galaxies with low SFR or low H I content.

Accepted by ApJ

References in corpus (35)

• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project
• Constraining the Low-Mass Slope of the Star Formation Sequence at 0.5<z<2.5
• SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and Accurate Rotation Curves
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• The Atomic to Molecular Transition in Galaxies. II: HI and H_2 Column Densities
• What is Driving the HI Velocity Dispersion?
• Molecular and atomic gas along and across the main sequence of star-forming galaxies
• The Baryon Content of Extremely Low Mass Dwarf Galaxies
• The star formation main sequence and stellar mass assembly of galaxies in the Illustris simulation
• Science With The Australian Square Kilometre Array Pathfinder
• The rotation curves shapes of late-type dwarf galaxies
• HI holes and high-velocity clouds in the spiral galaxy NGC 6946
• The Northern HIPASS catalogue - Data presentation, completeness and reliability measures
• Star formation is boosted (and quenched) from the inside out: radial star formation profiles from MaNGA
• The mass distribution in early-type disk galaxies: declining rotation curves and correlations with optical properties
• The HI content of star-forming galaxies at z = 0.24
• PHANGS CO kinematics: disk orientations and rotation curves at 150 pc resolution
• The Luminosity Dependence of the Galaxy Merger Rate
• Rotation and Mass in the Milky Way and Spiral Galaxies
• xGASS: HI fueling of star formation in disk-dominated galaxies
• Nearly all Massive Quiescent Disk Galaxies have a Surprisingly Large Atomic Gas Reservoir
• A New H I Survey of Active Galaxies
• The Effect of Local Galaxy Surface Density on Star Formation for HI selected galaxies
• Star Formation and Quenching of Central Galaxies from Stacked HI Measurements
• Spiral Structure Boosts Star Formation in Disk Galaxies
• xGASS: Robust quantification of asymmetries in global HI spectra and their relationship to environmental processes
• On the Determination of Rotation Velocity and Dynamical Mass of Galaxies Based on Integrated H I Spectra
• xGASS: passive disks do not host unexpectedly large reservoirs of cold atomic hydrogen
• What is Important? Morphological Asymmetries are Useful Predictors of Star Formation Rates of Star-forming Galaxies in SDSS Stripe 82
• Relationships between the Stellar, Gaseous, and Star Formation Disks in LITTLE THINGS Dwarf Irregular Galaxies: Indirect Evidence for Substantial Fractions of Dark Molecular Gas
• The Activation of Galactic Nuclei and Their Accretion Rates are Linked to the Star Formation Rates and Bulge-types of Their Host Galaxies
• A Simple Model for Global HI Profiles of Galaxies
• From major merger to radio galaxy: low surface-brightness stellar counterpart to the giant HI ring around B2 0648+27
• Discovery of a large HI ring around the quiescent galaxy AGC 203001

Cited by in corpus (8)

• Statistical Analysis of H I Profile Asymmetry and Shape for Nearby Galaxies
• FEASTS: IGM cooling triggered by tidal interactions through the diffuse HI phase around NGC 4631
• Probing the cold neutral medium through HI emission morphology with the scattering transform
• The ALMaQUEST Survey XV: The Dependence of the Molecular-to-Atomic Gas Ratios on Resolved Optical Diagnostics
• The Qz5 Survey (I): How the HI Mass Density of the Universe Evolves With Cosmic Time
• MUSE-ALMA Haloes XIII. Molecular gas in $z\sim 0.5$ HI-selected galaxies
• Recent Developments on the HI Gas of Low-Redshift Galaxies Seen by the 21cm Emission Lines
• The FAST Hundred-Deg${}^2$ HI Deep (HD${}^2$) Survey: Early Results from the Pilot Survey