AAS 199th meeting, Washington, DC, January 2002
Session 91. Stellar Populations and Galactic Structure
Display, Wednesday, January 9, 2002, 9:20am-6:30pm, Exhibit Hall

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[91.12] A Keck/AO deep luminosity function of the Galactic Bulge in Baade's Window obtained using the NIRC2 camera

M. Barczys, R.M. Rich, J. Larkin (UCLA), K. Matthews, K. Matthews, W.E. Althouse (Caltech), R.D. Campbell, A. Conrad (CARA), E. Egami (Caltech), A. Conrad, R.W. Goodrich (CARA), A. Honey, S. Lin (Caltech), I.S. McLean (UCLA), D. LeMignant, G. Neugebauer, M. Sawicki, B.T. Soifer, M. Spencer, D.M. Thompson (Caltech), P. Wizinowich (CARA)

We report analysis of deep, diffraction-limited infrared H and K band images of the Galactic bulge field of Baade's Window (l,b =1, -4\circ) obtained using the Keck II telescope and the newly commissioned NIRC2 camera. AO correction using a natural guide star was achieved using a bright V=7 mag foreground star. The field is well corrected over a radius of ~20\prime\prime and we are easily avoiding the confusion limit; all of the detected images are well resolved. We reach a limiting magnitude near H=23, corresponding to MH=+9 which is within 1-2 mag of the end of the hydrogen burning main sequence, and reaching to stellar masses in the range of 0.15 M\odot. We compare our photometry with deep images obtained by NICMOS on board HST and confirm that the luminosity function is continuing to rise at the faint end just as was found in the HST data. The large numbers of low mass stars suggest that they, rather than a large population of brown dwarfs are the lenses responsible for the majority of microlensing events observed toward the Galactic bulge.

The author(s) of this abstract have provided an email address for comments about the abstract: barczysm@astro.ucla.edu

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