Detection of M31 Binaries via High-Cadence Pixel-Lensing Surveys

• Published in: arXiv.org 2007-01
• Main Authors: Kim, D, S -J Chung, Darnley, M J, Duke, J P, Gould, A, Han, C, Ibrahimov, M A, M Im, Y -B Jeon, Karimov, R G, Kerins, E, C -U Lee, Newsam, A, B -G Park
• Format: Article
• Language: English
• Subjects: Andromeda Galaxy; Binary stars; Computer networks; Galaxies; Lenses; Mass ratios; Pixels; Telescopes
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0701588

The Angstrom Project is using a distributed network of two-meter class telescopes to conduct a high cadence pixel-lensing survey of the bulge of the Andromeda Galaxy (M31). With the expansion of global telescope network, the detection efficiency of pixel-lensing surveys is rapidly improving. In this paper, we estimate the detection rate of binary lens events expected from high-cadence pixel-lensing surveys toward M31 such as the Angstrom Project based on detailed simulation of events and application of realistic observational conditions. Under the conservative detection criteria that only high signal-to-noise caustic-crossing events with long enough durations between caustic crossings can be firmly identified as binary lens events, we estimate that the rate would be \(\Gamma_{\rm b}\sim (7-15)f_{\rm b}(N/50)\) per season, where \(f_{\rm b}\) is the fraction of binaries with projected separations of \(10^{-3} {\rm AU}