The MACHO Project: Microlensing Toward the Galactic Bulge
Session 17 -- Macho Projects
Display presentation, Monday, 9, 1995, 9:20am - 6:30pm

## [17.03] The MACHO Project: Microlensing Toward the Galactic Bulge

D.P. Bennett, S. Perlmutter (CfPA/UC Berkeley), C. Alcock, K. Cook (LLNL), R. Allsman (ANUSF), T. Axelrod, K. Freeman, B. Peterson, P. Quinn, A. Rodgers (MSSSO), K. Griest (CfPA/UCSD), M. Pratt, S. Marshall (CfPA/UCSB), C. Stubbs (CfPA/U Washington), W. Sutherland (Oxford)

The MACHO project has recently completed the analysis of 24 Galactic bulge fields containing $1.3\times 10^7$ stars observed for 190 days. Approximately 45 microlensing events have been detected in this data set. These data confirm results of the MACHO and OGLE collaborations based on smaller data samples which indicated a large microlensing optical depth toward the bulge. The variation of the microlensing optical depth and event rate with galactic lattitude and longitude is investigated and compared with maximal disk" and Galactic bar models which have been proposed to account for the observed optical depth toward the bulge. These results indicate that the study of microlensing toward the Galactic bulge will have important implications for the structure of the Galaxy and its dark halo.