Star formation in blue galaxies

Abstract

view Abstract Citations (201) References (63) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Star formation in blue galaxies. Huchra, J. P. Abstract Three simple classes of model galaxies ('old', 'young', and 'composite') are examined in order to study the star-formation histories and initial mass functions (IMFs) required to produce the bluest galaxies. It is found that old galaxy models fit the observed colors and H-beta emission if they have sufficiently flat IMFs or, for somewhat steeper IMFs, nearly constant rates of star formation. Young models are shown to fit the observations if they are internally reddened by 1 to 2 magnitudes of visual extinction. It is noted, however, that both the relatively low values of measured internal absorption and the color-absolute-magnitude data for the bluest galaxies mitigate against the young-galaxy hypothesis. The results for the composite galaxy models indicate that such galaxies fit the observed colors without reddening but require IMFs flatter than the Salpeter function in order to fit the observed H-beta emission. It is tentatively concluded that at least some blue galaxies are forming stars with an IMF flatter than the Salpeter function. Publication: The Astrophysical Journal Pub Date: November 1977 DOI: 10.1086/155638 Bibcode: 1977ApJ...217..928H Keywords: Astronomical Models; Galactic Structure; Luminous Intensity; Star Formation; Color; H Beta Line; Interstellar Extinction; Astrophysics full text sources ADS | data products SIMBAD (23)