IMF from UV stellar photometry

DOI

UV stellar photometry is presented for 1563 stars within a 40' circular field in the LMC, excluding the 10'x10' field centered on R136 investigated earlier by Hill et al. (1993). Magnitudes are computed from images obtained by the Ultraviolet Imaging Telescope in bands centered at 1615A and 2558A. Stellar masses and extinctions are estimated for the stars in associations using the evolutionary models of Schaerer et al. (1993), assuming the age is 4Myr and that the local LMC extinction follows the Fitzpatrick (1985) 30 Dor extinction curve. The estimated slope of the initial mass function (IMF) for massive stars (>15M_{sun}_) within the Lucke and Hodge (LH) associations is {gamma}=-1.08+/-0.2. Initial masses and extinctions for stars not within LH associations are estimated assuming that the stellar age is either 4Myr or half the stellar lifetime, whichever is larger. The estimated slope of the IMF for massive stars not within LH associations is {gamma}=-1.74+/-0.3 (assuming continuous star formation), compared with {gamma}=-1.35, and {gamma}=-1.7+/-0.5, obtained for the Galaxy by Salpeter (1955) and Scalo (1986), respectively, and {gamma}=-1.6 obtained for massive stars in the Galaxy by Garmany, Conti, & Chiosi (1982). The shallower slope of the association IMF suggests that not only is the star formation rate higher in associations, but that the local conditions favor the formation of higher mass stars there. We make no corrections for binaries or incompleteness.

Identifier
DOI http://doi.org/10.26093/cds/vizier.14250122
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/425/122
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/425/122
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/425/122
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/425/122
Provenance
Creator HILL J.K.; ISENSEE J.E.; CORNETT R.H.; BOHLIN R.C.; O'CONNELL R.W.,ROBERTS M.S.; SMITH A.M.; STECHER T.P.
Publisher CDS
Publication Year 1997
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy