A study of star formation in the disks of Sa galaxies

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169839· OSTI ID:5638241

Caldwell, N; Kennicutt, R; Phillips, A C; Schommer, R A ^[1]

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1. F.L. Whipple Observatory, Amado, AZ (USA) Steward Observatory, Tucson, AZ (USA) Washington Univ., Seattle (USA) Rutgers Univ., Piscataway, NJ (USA)

This paper compares the luminosity functions of the H II regions in several Sa galaxies with those of later-type galaxies. Broad UV measurements confirm expectations that the knots associated with the regions are very blue; the converse is also true. The H II region luminosity functions are very steep. The total H-alpha luminosities for the galaxies are computed and used to derive the current star-formation rates. It is found that, in contrast to the late-type galaxies, the current star-formation rates in Sa disks are less than one-tenth of the average rate over the last 15 Gyr. The formal depletion times of gas through star formation are longer than a Hubble time. If the star formation in late-type galaxies takes on the character of that currently seen in the Sas, star formation in such galaxies could continue for much longer than the usual estimate of 5 Gyr. 35 refs.

• OSTI ID: 5638241
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 370; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
CHARGE-COUPLED DEVICES
COMPARATIVE EVALUATIONS
COSMIC GASES
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
FLUIDS
GALACTIC EVOLUTION
GALAXIES
GASES
H2 REGIONS
LUMINOSITY
MEASURING INSTRUMENTS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
SEMICONDUCTOR DEVICES
SPECTROMETERS
STAR CLUSTERS
STAR EVOLUTION
ULTRAVIOLET RADIATION