Stellar Populations in the Large Magellanic Cloud from 2MASS

We present a morphological analysis of the feature-rich 2MASS LMCcolor-magnitude diagram, identifying Galactic and LMC populations andestimating the density of LMC populations alone. We also present the projectedspatial distributions of various stellar populations. Major populations areidentified based on matching morphological features of the CMD with expectedpositions of known populations, isochrone fits, and analysis of the projectedspatial distributions. The LMC populations along the first-ascent RGB and AGBare quantified. We find the RGB tip at Kₛ=12.3\±0.1. Preliminary isochroneanalysis is done for giant populations in the bar and the outer regions of theCloud. We find no significant differences in metallicities and ages between thefields. The observed LMC giant branch is well-fit by published tracks in theCIT/CTIO system with a distance modulus of \μ=18.5\±0.1, reddeningEB-V=0.15-0.20, metallicity Z=0.004+0.002-0.001 and age 3-13 Gyr.Analysis of deep 2MASS engineering data with six times the standard exposureproduces similar estimates.