  We present the first M31 candidate microlensing events from the Microlensing
Exploration of the Galaxy and Andromeda (MEGA) survey. MEGA uses several
telescopes to detect microlensing towards the nearby Andromeda galaxy, M31, in
order to establish whether massive compact objects are a significant
contribution to the mass budget of the dark halo of M31. The results presented
here are based on observations with the Isaac Newton Telescope on La Palma,
during the 1999/00 and 2000/01 observing seasons. In this data set, 14 variable
sources consistent with microlensing have been detected, 12 of which are new
and 2 have been reported previously by the POINT-AGAPE group. A preliminary
analysis of the spatial and timescale distributions of the candidate events
support their microlensing nature. We compare the spatial distributions of the
candidate events and of long-period variable stars, assuming the chances of
finding a long-period variable and a microlensing event are comparable. The
spatial distribution of our candidate microlensing events is more far/near side
asymmetric than expected from the detected long-period variable distribution.
The current analysis is preliminary and the asymmetry not highly significant,
but the spatial distribution of candidate microlenses is suggestive of the
presence of a microlensing halo.

Astrophysics