A systematic fitting scheme for caustic-crossing microlensing events

N. Kains, A. Cassan, K. Horne, M. D. Albrow, S. Dieters, P. Fouqué, J. Greenhill, A. Udalski, M. Zub, D. P. Bennett, M. Dominik, J. Donatowicz, D. Kubas, Y. Tsapras, T. Anguita, V. Batista, J. P. Beaulieu, S. Brillant, M. Bode, D. M. Bramich & 25 others M. Burgdorf, J. A R Caldwell, K. H. Cook, Ch Coutures, D. Dominis Prester, U. G. Jørgensen, S. Kane, J. B. Marquette, R. Martin, J. Menzies, K. R. Pollard, N. Rattenbury, K. C. Sahu, C. Snodgrass, I. Steele, C. Vinter, J. Wambsganss, A. Williams, M. Kubiak, G. Pietrzyński, I. Soszyński, O. Szewczyk, M. K. Szymański, K. Ulaczyk, L. Wyrzykowski

Research output: Contribution to journalArticle

12 Citations (Scopus)

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.

Original languageEnglish
Pages (from-to)787-796
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Volume395
Issue number2
DOIs
Publication statusPublished - 1 May 2009
Externally publishedYes

Fingerprint

alkalies
Markov chains
Markov chain
physical property
physical properties
lenses
methodology
parameter
estimates
modeling
method

Keywords

  • Binaries: general
  • Galaxy: bulge
  • Gravitational lensing
  • Methods: miscellaneous
  • Planetary systems

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Kains, N., Cassan, A., Horne, K., Albrow, M. D., Dieters, S., Fouqué, P., ... Wyrzykowski, L. (2009). A systematic fitting scheme for caustic-crossing microlensing events. Monthly Notices of the Royal Astronomical Society, 395(2), 787-796. https://doi.org/10.1111/j.1365-2966.2009.14615.x

A systematic fitting scheme for caustic-crossing microlensing events. / Kains, N.; Cassan, A.; Horne, K.; Albrow, M. D.; Dieters, S.; Fouqué, P.; Greenhill, J.; Udalski, A.; Zub, M.; Bennett, D. P.; Dominik, M.; Donatowicz, J.; Kubas, D.; Tsapras, Y.; Anguita, T.; Batista, V.; Beaulieu, J. P.; Brillant, S.; Bode, M.; Bramich, D. M.; Burgdorf, M.; Caldwell, J. A R; Cook, K. H.; Coutures, Ch; Dominis Prester, D.; Jørgensen, U. G.; Kane, S.; Marquette, J. B.; Martin, R.; Menzies, J.; Pollard, K. R.; Rattenbury, N.; Sahu, K. C.; Snodgrass, C.; Steele, I.; Vinter, C.; Wambsganss, J.; Williams, A.; Kubiak, M.; Pietrzyński, G.; Soszyński, I.; Szewczyk, O.; Szymański, M. K.; Ulaczyk, K.; Wyrzykowski, L.

In: Monthly Notices of the Royal Astronomical Society, Vol. 395, No. 2, 01.05.2009, p. 787-796.

Research output: Contribution to journalArticle

Kains, N, Cassan, A, Horne, K, Albrow, MD, Dieters, S, Fouqué, P, Greenhill, J, Udalski, A, Zub, M, Bennett, DP, Dominik, M, Donatowicz, J, Kubas, D, Tsapras, Y, Anguita, T, Batista, V, Beaulieu, JP, Brillant, S, Bode, M, Bramich, DM, Burgdorf, M, Caldwell, JAR, Cook, KH, Coutures, C, Dominis Prester, D, Jørgensen, 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, Pietrzyński, G, Soszyński, I, Szewczyk, O, Szymański, MK, Ulaczyk, K & Wyrzykowski, L 2009, 'A systematic fitting scheme for caustic-crossing microlensing events', Monthly Notices of the Royal Astronomical Society, vol. 395, no. 2, pp. 787-796. https://doi.org/10.1111/j.1365-2966.2009.14615.x
Kains, N. ; Cassan, A. ; Horne, K. ; Albrow, M. D. ; Dieters, S. ; Fouqué, P. ; Greenhill, J. ; Udalski, A. ; Zub, M. ; Bennett, D. P. ; Dominik, M. ; Donatowicz, J. ; Kubas, D. ; Tsapras, Y. ; Anguita, T. ; Batista, V. ; Beaulieu, J. P. ; Brillant, S. ; Bode, M. ; Bramich, D. M. ; Burgdorf, M. ; Caldwell, J. A R ; Cook, K. H. ; Coutures, Ch ; Dominis Prester, D. ; Jørgensen, U. G. ; Kane, S. ; Marquette, J. B. ; Martin, R. ; Menzies, J. ; Pollard, K. R. ; Rattenbury, N. ; Sahu, K. C. ; Snodgrass, C. ; Steele, I. ; Vinter, C. ; Wambsganss, J. ; Williams, A. ; Kubiak, M. ; Pietrzyński, G. ; Soszyński, I. ; Szewczyk, O. ; Szymański, M. K. ; Ulaczyk, K. ; Wyrzykowski, L. / A systematic fitting scheme for caustic-crossing microlensing events. In: Monthly Notices of the Royal Astronomical Society. 2009 ; Vol. 395, No. 2. pp. 787-796.
@article{7ab5a384479141f6bb9c3101b8118781,
title = "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 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.",
keywords = "Binaries: general, Galaxy: bulge, Gravitational lensing, Methods: miscellaneous, Planetary systems",
author = "N. Kains and A. Cassan and K. Horne and Albrow, {M. D.} and S. Dieters and P. Fouqu{\'e} and J. Greenhill and A. Udalski and M. Zub and Bennett, {D. P.} and M. Dominik and J. Donatowicz and D. Kubas and Y. Tsapras and T. Anguita and V. Batista and Beaulieu, {J. P.} and S. Brillant and M. Bode and Bramich, {D. M.} and M. Burgdorf and Caldwell, {J. A R} and Cook, {K. H.} and Ch Coutures and {Dominis Prester}, D. and J{\o}rgensen, {U. G.} and S. Kane and Marquette, {J. B.} and R. Martin and J. Menzies and Pollard, {K. R.} and N. Rattenbury and Sahu, {K. C.} and C. Snodgrass and I. Steele and C. Vinter and J. Wambsganss and A. Williams and M. Kubiak and G. Pietrzyński and I. Soszyński and O. Szewczyk and Szymański, {M. K.} and K. Ulaczyk and L. Wyrzykowski",
year = "2009",
month = "5",
day = "1",
doi = "10.1111/j.1365-2966.2009.14615.x",
language = "English",
volume = "395",
pages = "787--796",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "2",

}

TY - JOUR

T1 - A systematic fitting scheme for caustic-crossing microlensing events

AU - Kains, N.

AU - Cassan, A.

AU - Horne, K.

AU - Albrow, M. D.

AU - Dieters, S.

AU - Fouqué, P.

AU - Greenhill, J.

AU - Udalski, A.

AU - Zub, M.

AU - Bennett, D. P.

AU - Dominik, M.

AU - Donatowicz, J.

AU - Kubas, D.

AU - Tsapras, Y.

AU - Anguita, T.

AU - Batista, V.

AU - Beaulieu, J. P.

AU - Brillant, S.

AU - Bode, M.

AU - Bramich, D. M.

AU - Burgdorf, M.

AU - Caldwell, J. A R

AU - Cook, K. H.

AU - Coutures, Ch

AU - Dominis Prester, D.

AU - Jørgensen, U. G.

AU - Kane, S.

AU - Marquette, J. B.

AU - Martin, R.

AU - Menzies, J.

AU - Pollard, K. R.

AU - Rattenbury, N.

AU - Sahu, K. C.

AU - Snodgrass, C.

AU - Steele, I.

AU - Vinter, C.

AU - Wambsganss, J.

AU - Williams, A.

AU - Kubiak, M.

AU - Pietrzyński, G.

AU - Soszyński, I.

AU - Szewczyk, O.

AU - Szymański, M. K.

AU - Ulaczyk, K.

AU - Wyrzykowski, L.

PY - 2009/5/1

Y1 - 2009/5/1

N2 - 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.

AB - 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.

KW - Binaries: general

KW - Galaxy: bulge

KW - Gravitational lensing

KW - Methods: miscellaneous

KW - Planetary systems

UR - http://www.scopus.com/inward/record.url?scp=65349166306&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=65349166306&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2966.2009.14615.x

DO - 10.1111/j.1365-2966.2009.14615.x

M3 - Article

VL - 395

SP - 787

EP - 796

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 2

ER -