Properties of H II region populations in galaxies. II. The H II region luminosity function

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/167147· OSTI ID:6068027

Kennicutt, Jr, R C; Edgar, B K; Hodge, P W

H-alpha emission-line fluxes have been measured for all of the detected H II regions in 30 nearby spiral and irregular galaxies, and these data are used to study the behavior of the H II region luminosity functions (LFs). In most galaxies, the LF is well represented by a power law function. Both the normalization and the shape of the LF change systematically with Hubble type. Early-type spirals possess fewer H II regions of all luminosities, a steeper LF, and in many cases an upper cutoff or turnover in the LF. Taken together, these effects account for the virtual absence of 'supergiant' H II regions such as 30 Doradus in Sa-Sb galaxies. Most of the massive stars in late-type spiral and irregular galaxies form in large H II/OB complexes, while in early-type spirals the bulk of the massive star formation occurs in small regions ionized by no more than a few OB stars. 59 references.

• Research Organization: Minnesota Univ., Minneapolis (USA); Washington Univ., Seattle (USA)
• OSTI ID: 6068027
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 337; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
BALMER LINES
BRIGHTNESS
CHARGE-COUPLED DEVICES
CONFIGURATION
COSMIC RADIO SOURCES
EMISSION SPECTRA
GALAXIES
H2 REGIONS
LUMINOSITY
OPTICAL PROPERTIES
PHOTOMETRY
PHYSICAL PROPERTIES
SEMICONDUCTOR DEVICES
SIZE
SPECTRA
SPIRAL CONFIGURATION
STAR EVOLUTION