Starbursts and Extra-planar H-alpha from SINGG [article]

Gerhardt R. Meurer
2003 arXiv   pre-print
The NOAO Survey for Ionization in Neutral Gas Galaxies (SINGG) is the largest star formation survey of an HI selected sample. Since the selection is made without regard to optical morphology, it is not biased toward or against "interesting" types of galaxies; thus SINGG is an ideal sample for studying galaxy demographics. Of a sample of 90 extra-galactic sources observed in photometric conditions, all are detected in H-alpha. This indicates that dormant galaxies, those containing an appreciable
more » ... ISM but no star formation, are at best rare. We have made first pass morphological surveys for starbursts, as judged by H-alpha surface brightness, and outflows as judged by extra-planar H-alpha. We find that about 15% of the sources contain starbursts, with little dependence on the neutral hydrogen mass MHI. Nearly one half of a sample ~35 edge-on galaxies show evidence for extra-planar H-alpha having a scale size of 0.5 Kpc or larger, while nearly one quarter have extra-planar H-alpha features 1.0 Kpc in size or larger. There is a hint that high MHI systems preferentially have displaced outflows (chimneys, or fountains) while central outflows (galactic winds) preferentially occur in low MHI systems. However, a larger sample (e.g. the full SINGG survey) is needed to confirm this trend.
arXiv:astro-ph/0311184v1 fatcat:qnamgb5dujfmnj6wbofwh27r6e