A systematic fitting scheme for caustic-crossing microlensing events
- Creators
- Kains, N.
- Cassan, A.
- Horne, K.
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Albrow, M. D.
- Dieters, S.
- Fouqué, P.
- Greenhill, J.
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Udalski, A.
- Zub, M.
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Bennett, D. P.
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Dominik, M.
- Donatowicz, J.
- Kubas, D.
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Tsapras, Y.
- Anguita, T.
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Batista, V.
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Beaulieu, J. P.
- Brillant, S.
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Bode, M.
- Bramich, D. M.
- Burgdorf, M.
- Caldwell, J. A. R.
- Cook, K. H.
- Coutures, Ch.
- Dominis-Prester, D.
- Jørgensen, U. G.
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Kane, S.
- Marquette, J. B.
- Martin, R.
- Menzies, J.
- Pollard, K. R.
- Rattenbury, N.
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Sahu, K. C.
- Snodgrass, C.
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Steele, I.
- Vinter, C.
- Wambsganss, J.
- Williams, A.
- Kubiak, M.
- Pietrzyński, G.
- Soszyński, I.
- Szewczyk, O.
- Szymański, M. K.
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Ulaczyk, K.
- Wyrzykowski, Ł.
Abstract
We 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- χ2 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.
Additional Information
© 2009 RAS. Accepted 2009 February 9. Received 2009 February 9; in original form 2008 November 12. NK acknowledges STFC studentship PA/S/S/2006/04497 and an STFC travel grant covering his observing run at La Silla. We thank David Warren for financial support for the Mt Canopus Observatory. NK thanks Pascal Fouqué for organizing a workshop in Toulouse in 2007 November, and Joachim Wambsganss and Arnaud Cassan for their invitation to visit the Astronomisches Rechen-Institut in Heidelberg in 2008 April. We would like to thank the anonymous referee for helpful comments on the manuscript. We also thank the University of Tasmania for access to their TPAC supercomputer on which part of the calculations were carried out. PF expresses his gratitude to ESO for a two months invitation at Santiago headquarters, Chile, in 2008 October and November. The OGLE project is partially supported by the Polish MNiSW grant N20303032/4275.Attached Files
Published - Kains2009p2387Mon_Not_R_Astron_Soc.pdf
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Additional details
- Eprint ID
- 15635
- Resolver ID
- CaltechAUTHORS:20090904-142928631
- PA/S/S/2006/04497
- Science and Technology Facilities Council (STFC)
- N20303032/4275
- Ministerstwo Nauki i Szkolnictwa Wyższego (MNiSW)
- Created
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2009-09-14Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)