Gas accretion from halos to disks: observations, curiosities, and problems

Abstract

Accretion of gas from the cosmic web to galaxy halos and ultimately their disks is a prediction of modern cosmological models but is rarely observed directly or at the full rate expected from star formation. Here we illustrate possible large-scale cosmic HI accretion onto the nearby dwarf starburst galaxy IC10, observed with the VLA and GBT. We also suggest that cosmic accretion is the origin of sharp metallicity drops in the starburst regions of other dwarf galaxies, as observed with the 10-m GTC. Finally, we question the importance of cosmic accretion in normal dwarf irregulars, for which a recent study of their far-outer regions sees no need for, or evidence of, continuing gas buildup.

5 pages, 3 figures, IAU Symposium 317, Honolulu HI August 2015

References in corpus (6)

• Deriving model-based T${}_e$-consistent chemical abundances in ionised gaseous nebulae
• Localized starbursts in dwarf galaxies produced by impact of low metallicity cosmic gas clouds
• Metallicity inhomogeneities in local star-forming galaxies as sign of recent metal-poor gas accretion
• A Star Formation Law for Dwarf Irregular Galaxies
• Gaseous infall triggering starbursts in simulated dwarf galaxies
• The HI Chronicles of LITTLE THINGS BCDs II: The Origin of IC 10's HI Structure