Stellar Systems Group

Úbeda, Leonardo; Maíz-Apellániz, Jesús; MacKenty, John W.
The Astronomical Journal, Volume 133, Issue 3, pp. 932-951.
03/2007

ABSTRACT

We present the results of a detailed UV-optical study of the nearby dwarf starburst galaxy NGC 4214 using multifilter Hubble Space Telescope WFPC2 and STIS photometry. The stellar extinction is found to be quite patchy, with some areas having values of E(4405-5495)<0.1 mag and others, associated with star-forming regions, much more heavily obscured, a result that is consistent with previous studies of the nebular extinction. We determined the ratio of blue to red supergiants and found it to be consistent with theoretical models for the metallicity of the Small Magellanic Cloud. The stellar initial mass function (IMF) of the field in the range 20-100 M_solar is found to be steeper than γ=-2.8 (γ=-2.35 for a Salpeter IMF). A number of massive clusters and associations with ages between a few and 200 Myr are detected, and their properties are discussed.

Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.