Galactic Bulge Microlensing Events with Clump Giants as Sources
Astrophysics
2007-05-23 v1
Abstract
We present preliminary results of the analysis of 5 years of MACHO data on the Galactic bulge microlensing events with clump giants as sources. In particular, we discuss: 1) the selection of `giant' events, 2) distribution of impact parameters, 3) distribution of event durations, 4) the concentration of long duration events in MACHO field 104 centered on (l,b) = (3.1,-3.0). We report the preliminary average optical depth of (2.0 +/- 0.4) x 10^{-6} (internal) at (l,b) = (3.9,-3.8). We discuss future work and prospects for building a coherent model of the Galaxy.
Cite
@article{arxiv.astro-ph/0005466,
title = {Galactic Bulge Microlensing Events with Clump Giants as Sources},
author = {P. Popowski and C. Alcock and R. A. Allsman and D. R. Alves and T. S. Axelrod and A. C. Becker and D. P. Bennett and K. H. Cook and A. J. Drake and K. C. Freeman and M. Geha and K. Griest and M. J. Lehner and S. L. Marshall and D. Minniti and C. A. Nelson and B. A. Peterson and M. R. Pratt and P. J. Quinn and C. W. Stubbs and W. Sutherland and A. B. Tomaney and T. Vandehei and D. Welch},
journal= {arXiv preprint arXiv:astro-ph/0005466},
year = {2007}
}
Comments
8 pages, 4 figures. To appear in ``Microlensing 2000: A New Era of Microlensing Astrophysics,'' an ASP conference proceedings, eds. J.W. Menzies and P.D. Sackett