S0S AND THE LOWER LIMIT OF STAR-FORMATION RATES IN DISK GALAXIES

Citation
N. Caldwell et al., S0S AND THE LOWER LIMIT OF STAR-FORMATION RATES IN DISK GALAXIES, The Astronomical journal, 108(4), 1994, pp. 1186-1190
Citations number
24
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046256
Volume
108
Issue
4
Year of publication
1994
Pages
1186 - 1190
Database
ISI
SICI code
0004-6256(1994)108:4<1186:SATLLO>2.0.ZU;2-D
Abstract
As an extension of our study of star formation and H II regions in Sa galaxies, we have observed eight disk galaxies classified SO-SO/Sa. We have detected discrete H II regions in three of these, all classified SO/Sa because their faint star-forming regions are visible on broadba nd images. Each of these galaxies has about 15 H II regions, with a to tal luminosity in H alpha between L = 10(38.3) and 10(37.7) ergs s(-1) . The star-formation rate in these galaxies implied by the Her luminos ity is less than 0.004.M(circle dot) yr(-1), as compared to greater th an 0.1.M(circle dot) yr(-1) in Sa galaxies. We conclude that normal st ar formation in disk galaxies can occur in exceedingly small amounts.