A systematic fitting scheme for caustic-crossing microlensing events
Abstract
We outline a method for fitting binary-lens caustic-crossing microlensing events based on the alternative model parameterisation proposed and detailed in Cassan (2008). As an illustration of our methodology, we present an analysis of OGLE-2007-BLG-472, a double-peaked Galactic microlensing event with a source crossing the whole caustic structure in less than three days. In order to identify all possible models we conduct an extensive search of the parameter space, followed by a refinement of the parameters with a Markov Chain-Monte Carlo algorithm. We find a number of low-chi2 regions in the parameter space, which lead to several distinct competitive best models. We examine the parameters for each of them, and estimate their physical properties. We find that our fitting strategy locates several minima that are difficult to find with other modelling strategies and is therefore a more appropriate method to fit this type of events.
Keywords
Cite
@article{arxiv.0901.1285,
title = {A systematic fitting scheme for caustic-crossing microlensing events},
author = {N. Kains and A. Cassan and K. Horne and M. D. Albrow and S. Dieters and P. Fouque and J. Greenhill and A. Udalski and M. Zub and D. P. Bennett and M. Dominik and J. Donatowicz and D. Kubas and Y. Tsapras and T. Anguita and V. Batista and J. -P. Beaulieu and S. Brillant and M. Bode and D. M. Bramich and M. Burgdorf and J. A. R. Caldwell and K. H. Cook and Ch. Coutures and D. Dominis Prester and U. G. Jorgensen and S. Kane and J. B. Marquette and R. Martin and J. Menzies and K. R. Pollard and N. Rattenbury and K. C. Sahu and C. Snodgrass and I. Steele and C. Vinter and J. Wambsganss and A. Williams and M. Kubiak and G. Pietrzynski and I. Soszynski and O. Szewczyk and M. K. Szymanski and K. Ulaczyk and L. Wyrzykowski},
journal= {arXiv preprint arXiv:0901.1285},
year = {2009}
}
Comments
12 pages, 11 figures