Stellar populations in the large magellanic cloud: Evidence for a significant number of older stars or a steeper IMF?
JA Holtzman, JR Mould, JS Gallagher, AM Watson, CJ Grillmair, GE Ballester, CJ Burrows, JT Clarke, D Crisp, RW Evans, RE Griffiths, JJ Hester, JG Hoessel, PA Scowen, KR Stapelfeldt, JT Trauger, JA Westphal
Astronomical Journal | Published : 1997
We present deep photometry obtained with the HST in an outer LMC field. A well-defined main sequence is seen down to V>26. We derive a luminosity function from the data and use it to constrain the IMF and the star formation history. We derive limits on the IMF slope, α (with dN/dM ∝ Mα), from stars on the main sequence which are fainter than the oldest turnoff. For most choices of star formation history and metallicity, we derive slopes which are consistent the Salpeter (α = -2.35) or local solar neighborhood IMF, although the preferred values are steeper. We can rule out IMF slopes shallower than -1.6 and steeper than -3.1 for the mass range 0.6≲M≲1.1 M⊙. Assuming a Salpeter IMF over the en..View full abstract