Toward Galactic Center


Aims. We present a new EROS-2 measurement of the microlensing optical depth toward the Galactic Bulge.
Methods Light curves of 5.6 × 106 clump-giant stars distributed over 66 deg2 of the Bulge were monitored during seven Bulge seasons. 120 events were found with apparent amplifications greater than 1.6 and Einstein radius crossing times in the range
5 d < te < 400 d. This is the largest existing sample of clump-giant events and the first to include northern Galactic fields.
Results. In the Galactic latitude range 1.4 < |b| < 7.0, we find &tau/10-6=(1.62 ± 0.23)exp[-a(|b| - 3 deg)] with a=(0.43 ± 0.16)deg-1. These results are in good agreement with our previous measurement, with recent measurements of the MACHO and OGLE-II groups, and with predictions of Bulge models.

Publication is available on astro-ph (number 0601510)

Light curves of the 120 candidates found :

Light curves DATA of the 120 candidates found :