The stellar content of NGC 3109

Abstract

view Abstract Citations (12) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Stellar Content of NGC 3109 Davidge, T. J. Abstract Deep B, V, and I CCD images are used to investigate the stellar content of a field along the major axis of the nearby dwarf galaxy NGC 3109. Stars spanning a wide range of ages are detected, and the youngest have ages between 10 and 30 million years. The width of the main sequence can be explained solely by observational uncertainties, indicating that star- to-star differences in reddening are small. The total line-of-sight reddening, derived from the main-sequence locus, is E( B - V) ~ 0.14. The distance modulus of NGC 3109 is rederived from published Cepheid photometry after assuming that the absorption measured in this field is representative of the galaxy in general, and the result is μ_0_ ~ 25.05. The luminosity function of upper main-sequence stars follows a well-defined power law with exponent 0.37+/-0.01. This is flatter than what is typically seen in other galaxies, and it is suggested that the shallow luminosity function may be the consequence of stochastic variations in the local star-forming history. Asymptotic giant branch (AGB) stars have also been detected. The AGB tip occurs near M_bol_~ -7.0, indicating that an intermediate-age population is present. Moreover, the bolometric luminosity function of AGB stars is identical to that seen in the Small Magellanic Cloud, a galaxy with similar integrated absolute brightness. Finally, the locus of the red giant branch is very blue, indicating that the old and intermediate-age populations are extremely metal-poor, with [Fe/H] <= - 1.6. Publication: The Astronomical Journal Pub Date: April 1993 DOI: 10.1086/116518 Bibcode: 1993AJ....105.1392D Keywords: Astronomical Photometry; Asymptotic Giant Branch Stars; Dwarf Galaxies; Interstellar Extinction; Star Distribution; Stellar Luminosity; Brightness Distribution; Cepheid Variables; Distance; Magellanic Clouds; Metallicity; Star Formation; Stellar Color; Astrophysics; GALAXIES: INDIVIDUAL: NGC 3109; GALAXIES: STELLAR CONTENT full text sources ADS | data products SIMBAD (13) NED (1)