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A systematic fitting scheme for caustic-crossing microlensing events
journal contribution
posted on 2023-05-16, 23:55 authored by Kains, N, Cassan, A, Horne, K, Albrow, MD, Dieters, S, Fouque, P, Greenhill, JG, Udalski, A, Zub, M, Bennett, DP, Dominik, M, Donatowicz, J, Kubas, D, Tsapras, Y, Anguita, T, Batista, V, Beaulieu, JP, Brilliant, S, Bode, M, Bramich, DM, Burgdorf, M, Caldwell, JAR, Cook, KH, Coutures, C, Dominis Prester, D, Jorgensen, UG, Kane, S, Marquette, JB, Martin, R, Menzies, J, Pollard, KR, Rattenbury, N, Sahu, KC, Snodgrass, C, Steele, I, Vinter, C, Wambsganss, J, Williams, A, Kubiak, M, Pietrzynski, G, Soszynski, I, Szewczyk, O, Szymanski, MK, Ulaczyk, K, Wyrzykowski, LWe outline a method for fitting binary-lens caustic-crossing microlensing events based on the alternative model parametrization proposed and detailed by Cassan. 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- ÷2 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 event.
History
Publication title
Monthly Notices of the Royal Astronomical SocietyVolume
395Pagination
787-796ISSN
0035-8711Department/School
School of Natural SciencesPublisher
Wiley-Blackwell Publishing IncPlace of publication
Malden, USARights statement
The definitive published version is available online at: http://interscience.wiley.comRepository Status
- Restricted