Morphology of Star Formation Regions in Irregular Galaxies

Abstract

The location of HII regions, which indicates the locus of present star formation in galaxies, is analyzed for a large collection of 110 irregular galaxies (Irr) imaged in H$\alpha$ and nearby continuum. The analysis is primarily by visual inspection, although a two-dimensional quantitative measure is also employed. The two different analyses yield essentially identical results. HII regions appear preferentially at the edges of the light distribution, predominantly on one side of the galaxy, contrary to what is expected from stochastic self-propagating star formation scenarios. This peculiar distribution of star forming regions cannot be explained by a scenario of star formation triggered by an interaction with extragalactic gas, or by a strong one-armed spiral pattern.

28 pages, four figures, accepted for publication in MNRAS

Cited by in corpus (8)

• Star Formation in Sculptor Group Dwarf Irregular Galaxies and the Nature of "Transition" Galaxies
• Deep Near Infrared Mapping of Young and Old Stars in Blue Compact Dwarf Galaxies
• Star Formation in Dwarf Galaxies of the Nearby Centaurus A Group
• On the Structural Differences between Disk and Dwarf Galaxies
• Neutral Hydrogen Mapping of Virgo Cluster Blue Compact Dwarf Galaxies
• Lopsidedness in dwarf irregular galaxies
• Distribution of star-forming complexes in dwarf irregular galaxies
• Star Formation Rate in late-type galaxies: I- The H(alpha) and FUV integrated values