AN EMPIRICAL CONNECTION BETWEEN THE ULTRAVIOLET COLOR OF EARLY-TYPE GALAXIES AND THE STELLAR INITIAL MASS FUNCTION

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/780/1/L1· OSTI ID:22364067

Zaritsky, Dennis ^[1]; Gil de Paz, Armando; Bouquin, Alexandre Y. K., ^[2]

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1. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
2. Departamento de Astrofísica y CC. de la Atmósfera, Facultad de CC. Físicas, Universidad Complutense de Madrid, Avda. de la Complutense s/n, Madrid E-28040 (Spain)

Using new UV magnitudes for a sample of early-type galaxies (ETGs) with published stellar mass-to-light ratios, Y{sub *}, we find a correlation between UV color and Y{sub *} that is tighter than those previously identified between Y{sub *} and either the central stellar velocity dispersion, metallicity, or alpha enhancement. The sense of the correlation is that galaxies with larger Y{sub *} are bluer in the UV. We conjecture that differences in the lower mass end of the stellar initial mass function (IMF) are related to the nature of the extreme horizontal branch populations that are generally responsible for the UV flux in ETGs. If so, then UV color can be used to identify ETGs with particular IMF properties and to estimate Y{sub *}.

• OSTI ID: 22364067
• Journal Information: Astrophysical Journal Letters, Vol. 780, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
COLOR
CORRELATIONS
GALACTIC EVOLUTION
GALAXIES
LUMINOSITY
MASS
METALLICITY
STARS
ULTRAVIOLET RADIATION
VELOCITY
VISIBLE RADIATION