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Session 107 - The Galactic Center & Bulge.
Display session, Saturday, January 10
Exhibit Hall,

[107.06] The Luminosity Function and Initial Mass Function in the Galactic Bulge

J. Holtzman (NMSU), WFPC ID Team, WFPC2 ID Team

We present deep photometry obtained with the HST in two fields in the Galactic bulge. We derive a luminosity function down to roughly I=24, (V=27.5), which corresponds to masses of approximately 0.3 solar masses. The luminosity function from the turnoff down to this level is similar to that observed in the solar neighborhood. We derive a mass function using both an empirical local mass-luminosity relation and a mass-luminosity relation from recent stellar model calculations; for the low-mass stars observed here, the present-day mass function should directly reflect the initial mass function. We include the effects of random and systematic photometric errors, as well as the possible presence of binaries, in our calculations. We find evidence for a break in the mass function slope around 0.5 solar masses, with a significantly shallower slope at lower masses, similar to what has been observed in the solar neighborhood. It does not appear that the Bulge is overabundant in low mass stars.

Program listing for Saturday