Characterizing lenses and lensed stars of high-magnification single-lens gravitational microlensing events with lenses passing over source stars

J. Y. Choi; I. G. Shin; S. Y. Park; C. Han; A. Gould; T. Sumi; A. Udalski; J. P. Beaulieu; R. Street; M. Dominik; W. Allen; L. A. Almeida; M. Bos; G. W. Christie; D. L. Depoy; S. Dong; J. Drummond; A. Gal-Yam; B. S. Gaudi; C. B. Henderson; L. W. Hung; F. Jablonski; J. Janczak; C. U. Lee; F. Mallia; A. Maury; J. McCormick; D. McGregor; L. A.G. Monard; D. Moorhouse; J. A. Muñoz; T. Natusch; C. Nelson; B. G. Park; R. W. Pogge; T. G. Tg Tan; G. Thornley; J. C. Yee; F. Abe; E. Barnard; J. Baudry; D. P. Bennett; I. A. Bond; C. S. Botzler; M. Freeman; A. Fukui; K. Furusawa; F. Hayashi; J. B. Hearnshaw; S. Hosaka; Y. Itow; K. Kamiya; P. M. Kilmartin; S. Kobara; A. Korpela; W. Lin; C. H. Ling; S. Makita; K. Masuda; Y. Matsubara; N. Miyake; Y. Muraki; M. Nagaya; K. Nishimoto; K. Ohnishi; T. Okumura; K. Omori; Y. C. Perrott; N. Rattenbury; To Saito; L. Skuljan; D. J. Sullivan; D. Suzuki; K. Suzuki; W. L. Sweatman; S. Takino; P. J. Tristram; K. Wada; P. C.M. Yock; M. K. Szymański; M. Kubiak; G. Pietrzyński; I. Soszyński; R. Poleski; K. Ulaczyk; null Wyrzykowski; S. Kozłowski; P. Pietrukowicz; M. D. Albrow; E. Bachelet; V. Batista; C. S. Bennett; R. Bowens-Rubin; S. Brillant; A. Cassan; A. Cole; E. Corrales; Ch Coutures; S. Dieters; D. Dominis Prester; J. Donatowicz; P. Fouqué; J. Greenhill; S. R. Kane; J. Menzies; K. C. Sahu; J. Wambsganss; A. Williams; M. Zub; A. Allan; D. M. Bramich; P. Browne; N. Clay; S. Fraser; K. Horne; N. Kains; C. Mottram; C. Snodgrass; I. Steele; Y. Tsapras; K. A. Alsubai; V. Bozza; M. J. Burgdorf; S. Calchi Novati; P. Dodds; S. Dreizler; F. Finet; T. Gerner; M. Glitrup; F. Grundahl; S. Hardis; K. Harpsoe; T. C. Hinse; M. Hundertmark; U. G. Jorgensen; E. Kerins; C. Liebig; G. Maier; L. Mancini; M. Mathiasen; M. T. Penny; S. Proft; S. Rahvar; D. Ricci; G. Scarpetta; S. Schäfer; F. Schönebeck; J. Skottfelt; J. Surdej; J. Southworth; F. Zimmer

doi:10.1088/0004-637X/751/1/41

Characterizing lenses and lensed stars of high-magnification single-lens gravitational microlensing events with lenses passing over source stars

J. Y. Choi, I. G. Shin, S. Y. Park, C. Han, A. Gould, T. Sumi, A. Udalski, J. P. Beaulieu, R. Street, M. Dominik, W. Allen, L. A. Almeida, M. Bos, G. W. Christie, D. L. Depoy, S. Dong, J. Drummond, A. Gal-Yam, B. S. Gaudi, C. B. HendersonL. W. Hung, F. Jablonski, J. Janczak, C. U. Lee, F. Mallia, A. Maury, J. McCormick, D. McGregor, L. A.G. Monard, D. Moorhouse, J. A. Muñoz, T. Natusch, C. Nelson, B. G. Park, R. W. Pogge, T. G. Tg Tan, G. Thornley, J. C. Yee, F. Abe, E. Barnard, J. Baudry, D. P. Bennett, I. A. Bond, C. S. Botzler, M. Freeman, A. Fukui, K. Furusawa, F. Hayashi, J. B. Hearnshaw, S. Hosaka, Y. Itow, K. Kamiya, P. M. Kilmartin, S. Kobara, A. Korpela, W. Lin, C. H. Ling, S. Makita, K. Masuda, Y. Matsubara, N. Miyake, Y. Muraki, M. Nagaya, K. Nishimoto, K. Ohnishi, T. Okumura, K. Omori, Y. C. Perrott, N. Rattenbury, To Saito, L. Skuljan, D. J. Sullivan, D. Suzuki, K. Suzuki, W. L. Sweatman, S. Takino, P. J. Tristram, K. Wada, P. C.M. Yock, M. K. Szymański, M. Kubiak, G. Pietrzyński, I. Soszyński, R. Poleski, K. Ulaczyk, Wyrzykowski, S. Kozłowski, P. Pietrukowicz, M. D. Albrow, E. Bachelet, V. Batista, C. S. Bennett, R. Bowens-Rubin, S. Brillant, A. Cassan, A. Cole, E. Corrales, Ch Coutures, S. Dieters, D. Dominis Prester, J. Donatowicz, P. Fouqué, J. Greenhill, S. R. Kane, J. Menzies, K. C. Sahu, J. Wambsganss, A. Williams, M. Zub, A. Allan, D. M. Bramich, P. Browne, N. Clay, S. Fraser, K. Horne, N. Kains, C. Mottram, C. Snodgrass, I. Steele, Y. Tsapras, K. A. Alsubai, V. Bozza, M. J. Burgdorf, S. Calchi Novati, P. Dodds, S. Dreizler, F. Finet, T. Gerner, M. Glitrup, F. Grundahl, S. Hardis, K. Harpsoe, T. C. Hinse, M. Hundertmark, U. G. Jorgensen, E. Kerins, C. Liebig, G. Maier, L. Mancini, M. Mathiasen, M. T. Penny, S. Proft, S. Rahvar, D. Ricci, G. Scarpetta, S. Schäfer, F. Schönebeck, J. Skottfelt, J. Surdej, J. Southworth, F. Zimmer

Department of Particle Physics and Astrophysics

Weizmann Institute of Science

Research output: Contribution to journal › Article › peer-review

Abstract

We present the analysis of the light curves of nine high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE- 2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/ MOA-2011-BLG-325. For all of the events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For seven events, we measure the Einstein radii and the lens-source relative proper motions. Among them, five events are found to have Einstein radii of less than 0.2 mas, making the lenses very low mass star or brown dwarf candidates. For MOA-2011-BLG-274, especially, the small Einstein radius of θ_E 0.08 mas combined with the short timescale of t _E 2.7days suggests the possibility that the lens is a free-floating planet. For MOA-2009-BLG-174, we measure the lens parallax and thus uniquely determine the physical parameters of the lens. We also find that the measured lens mass of 0.84 M _⊙ is consistent with that of a star blended with the source, suggesting that the blend is likely to be the lens. Although we did not find planetary signals for any of the events, we provide exclusion diagrams showing the confidence levels excluding the existence of a planet as a function of the separation and mass ratio.

Original language	English
Article number	41
Journal	Astrophysical Journal
Volume	751
Issue number	1
DOIs	https://doi.org/10.1088/0004-637X/751/1/41
State	Published - 2 May 2012

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1088/0004-637X/751/1/41

https://dspace.mit.edu/handle/1721.1/95529

Cite this

Choi, J. Y., Shin, I. G., Park, S. Y., Han, C., Gould, A., Sumi, T., Udalski, A., Beaulieu, J. P., Street, R., Dominik, M., Allen, W., Almeida, L. A., Bos, M., Christie, G. W., Depoy, D. L., Dong, S., Drummond, J., Gal-Yam, A., Gaudi, B. S., ... Zimmer, F. (2012). Characterizing lenses and lensed stars of high-magnification single-lens gravitational microlensing events with lenses passing over source stars. Astrophysical Journal, 751(1), Article 41. https://doi.org/10.1088/0004-637X/751/1/41

@article{fafc519b23884070b4fd03a25c2e0138,

title = "Characterizing lenses and lensed stars of high-magnification single-lens gravitational microlensing events with lenses passing over source stars",

abstract = "We present the analysis of the light curves of nine high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE- 2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/ MOA-2011-BLG-325. For all of the events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For seven events, we measure the Einstein radii and the lens-source relative proper motions. Among them, five events are found to have Einstein radii of less than 0.2 mas, making the lenses very low mass star or brown dwarf candidates. For MOA-2011-BLG-274, especially, the small Einstein radius of θE 0.08 mas combined with the short timescale of t E 2.7days suggests the possibility that the lens is a free-floating planet. For MOA-2009-BLG-174, we measure the lens parallax and thus uniquely determine the physical parameters of the lens. We also find that the measured lens mass of 0.84 M ⊙ is consistent with that of a star blended with the source, suggesting that the blend is likely to be the lens. Although we did not find planetary signals for any of the events, we provide exclusion diagrams showing the confidence levels excluding the existence of a planet as a function of the separation and mass ratio.",

author = "Choi, {J. Y.} and Shin, {I. G.} and Park, {S. Y.} and C. Han and A. Gould and T. Sumi and A. Udalski and Beaulieu, {J. P.} and R. Street and M. Dominik and W. Allen and Almeida, {L. A.} and M. Bos and Christie, {G. W.} and Depoy, {D. L.} and S. Dong and J. Drummond and A. Gal-Yam and Gaudi, {B. S.} and Henderson, {C. B.} and Hung, {L. W.} and F. Jablonski and J. Janczak and Lee, {C. U.} and F. Mallia and A. Maury and J. McCormick and D. McGregor and Monard, {L. A.G.} and D. Moorhouse and Mu{\~n}oz, {J. A.} and T. Natusch and C. Nelson and Park, {B. G.} and Pogge, {R. W.} and {Tg Tan}, {T. G.} and G. Thornley and Yee, {J. C.} and F. Abe and E. Barnard and J. Baudry and Bennett, {D. P.} and Bond, {I. A.} and Botzler, {C. S.} and M. Freeman and A. Fukui and K. Furusawa and F. Hayashi and Hearnshaw, {J. B.} and S. Hosaka and Y. Itow and K. Kamiya and Kilmartin, {P. M.} and S. Kobara and A. Korpela and W. Lin and Ling, {C. H.} and S. Makita and K. Masuda and Y. Matsubara and N. Miyake and Y. Muraki and M. Nagaya and K. Nishimoto and K. Ohnishi and T. Okumura and K. Omori and Perrott, {Y. C.} and N. Rattenbury and To Saito and L. Skuljan and Sullivan, {D. J.} and D. Suzuki and K. Suzuki and Sweatman, {W. L.} and S. Takino and Tristram, {P. J.} and K. Wada and Yock, {P. C.M.} and Szyma{\'n}ski, {M. K.} and M. Kubiak and G. Pietrzy{\'n}ski and I. Soszy{\'n}ski and R. Poleski and K. Ulaczyk and Wyrzykowski and S. Koz{\l}owski and P. Pietrukowicz and Albrow, {M. D.} and E. Bachelet and V. Batista and Bennett, {C. S.} and R. Bowens-Rubin and S. Brillant and A. Cassan and A. Cole and E. Corrales and Ch Coutures and S. Dieters and {Dominis Prester}, D. and J. Donatowicz and P. Fouqu{\'e} and J. Greenhill and Kane, {S. R.} and J. Menzies and Sahu, {K. C.} and J. Wambsganss and A. Williams and M. Zub and A. Allan and Bramich, {D. M.} and P. Browne and N. Clay and S. Fraser and K. Horne and N. Kains and C. Mottram and C. Snodgrass and I. Steele and Y. Tsapras and Alsubai, {K. A.} and V. Bozza and Burgdorf, {M. J.} and {Calchi Novati}, S. and P. Dodds and S. Dreizler and F. Finet and T. Gerner and M. Glitrup and F. Grundahl and S. Hardis and K. Harpsoe and Hinse, {T. C.} and M. Hundertmark and Jorgensen, {U. G.} and E. Kerins and C. Liebig and G. Maier and L. Mancini and M. Mathiasen and Penny, {M. T.} and S. Proft and S. Rahvar and D. Ricci and G. Scarpetta and S. Sch{\"a}fer and F. Sch{\"o}nebeck and J. Skottfelt and J. Surdej and J. Southworth and F. Zimmer",

note = "Work by C.H. was supported by the Creative Research Initiative Program (2009-0081561) of the National Research Foundation of Korea. The MOA experiment was supported by JSPS17340074, JSPS18253002, JSPS20340052, JSPS22403003, and JSPS23340064. The OGLE project has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement No. 246678. Work by B.S.G. and A.G. was supported in part by NSF grant AST-1103471. Work by B.S.G., A.G., R.W.P., and J.C.Y. was supported in part by NASA grant NNX08AF40G. Work by J.C.Y. was supported by a National Science Foundation Graduate Research Fellowship under grant No. 2009068160. C.B.H. acknowledges the support of NSF Graduate Research Fellowship 2011082275. T.S. was supported by the grants JSPS18749004, MEXT19015005, and JSPS20740104. F.F., D.R., and J.S. were supported by the Communaut{\'e} fran{\c c}aise de Belgique–Actions de recherche concert{\'e}es–Acad{\'e}mie universitaire Wallonie-Europe.",

year = "2012",

month = may,

day = "2",

doi = "10.1088/0004-637X/751/1/41",

language = "الإنجليزيّة",

volume = "751",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing Ltd.",

number = "1",

}

Choi, JY, Shin, IG, Park, SY, Han, C, Gould, A, Sumi, T, Udalski, A, Beaulieu, JP, Street, R, Dominik, M, Allen, W, Almeida, LA, Bos, M, Christie, GW, Depoy, DL, Dong, S, Drummond, J, Gal-Yam, A, Gaudi, BS, Henderson, CB, Hung, LW, Jablonski, F, Janczak, J, Lee, CU, Mallia, F, Maury, A, McCormick, J, McGregor, D, Monard, LAG, Moorhouse, D, Muñoz, JA, Natusch, T, Nelson, C, Park, BG, Pogge, RW, Tg Tan, TG, Thornley, G, Yee, JC, Abe, F, Barnard, E, Baudry, J, Bennett, DP, Bond, IA, Botzler, CS, Freeman, M, Fukui, A, Furusawa, K, Hayashi, F, Hearnshaw, JB, Hosaka, S, Itow, Y, Kamiya, K, Kilmartin, PM, Kobara, S, Korpela, A, Lin, W, Ling, CH, Makita, S, Masuda, K, Matsubara, Y, Miyake, N, Muraki, Y, Nagaya, M, Nishimoto, K, Ohnishi, K, Okumura, T, Omori, K, Perrott, YC, Rattenbury, N, Saito, T, Skuljan, L, Sullivan, DJ, Suzuki, D, Suzuki, K, Sweatman, WL, Takino, S, Tristram, PJ, Wada, K, Yock, PCM, Szymański, MK, Kubiak, M, Pietrzyński, G, Soszyński, I, Poleski, R, Ulaczyk, K, Wyrzykowski, Kozłowski, S, Pietrukowicz, P, Albrow, MD, Bachelet, E, Batista, V, Bennett, CS, Bowens-Rubin, R, Brillant, S, Cassan, A, Cole, A, Corrales, E, Coutures, C, Dieters, S, Dominis Prester, D, Donatowicz, J, Fouqué, P, Greenhill, J, Kane, SR, Menzies, J, Sahu, KC, Wambsganss, J, Williams, A, Zub, M, Allan, A, Bramich, DM, Browne, P, Clay, N, Fraser, S, Horne, K, Kains, N, Mottram, C, Snodgrass, C, Steele, I, Tsapras, Y, Alsubai, KA, Bozza, V, Burgdorf, MJ, Calchi Novati, S, Dodds, P, Dreizler, S, Finet, F, Gerner, T, Glitrup, M, Grundahl, F, Hardis, S, Harpsoe, K, Hinse, TC, Hundertmark, M, Jorgensen, UG, Kerins, E, Liebig, C, Maier, G, Mancini, L, Mathiasen, M, Penny, MT, Proft, S, Rahvar, S, Ricci, D, Scarpetta, G, Schäfer, S, Schönebeck, F, Skottfelt, J, Surdej, J, Southworth, J & Zimmer, F 2012, 'Characterizing lenses and lensed stars of high-magnification single-lens gravitational microlensing events with lenses passing over source stars', Astrophysical Journal, vol. 751, no. 1, 41. https://doi.org/10.1088/0004-637X/751/1/41

TY - JOUR

T1 - Characterizing lenses and lensed stars of high-magnification single-lens gravitational microlensing events with lenses passing over source stars

AU - Choi, J. Y.

AU - Shin, I. G.

AU - Park, S. Y.

AU - Han, C.

AU - Gould, A.

AU - Sumi, T.

AU - Udalski, A.

AU - Beaulieu, J. P.

AU - Street, R.

AU - Dominik, M.

AU - Allen, W.

AU - Almeida, L. A.

AU - Bos, M.

AU - Christie, G. W.

AU - Depoy, D. L.

AU - Dong, S.

AU - Drummond, J.

AU - Gal-Yam, A.

AU - Gaudi, B. S.

AU - Henderson, C. B.

AU - Hung, L. W.

AU - Jablonski, F.

AU - Janczak, J.

AU - Lee, C. U.

AU - Mallia, F.

AU - Maury, A.

AU - McCormick, J.

AU - McGregor, D.

AU - Monard, L. A.G.

AU - Moorhouse, D.

AU - Muñoz, J. A.

AU - Natusch, T.

AU - Nelson, C.

AU - Park, B. G.

AU - Pogge, R. W.

AU - Tg Tan, T. G.

AU - Thornley, G.

AU - Yee, J. C.

AU - Abe, F.

AU - Barnard, E.

AU - Baudry, J.

AU - Bennett, D. P.

AU - Bond, I. A.

AU - Botzler, C. S.

AU - Freeman, M.

AU - Fukui, A.

AU - Furusawa, K.

AU - Hayashi, F.

AU - Hearnshaw, J. B.

AU - Hosaka, S.

AU - Itow, Y.

AU - Kamiya, K.

AU - Kilmartin, P. M.

AU - Kobara, S.

AU - Korpela, A.

AU - Lin, W.

AU - Ling, C. H.

AU - Makita, S.

AU - Masuda, K.

AU - Matsubara, Y.

AU - Miyake, N.

AU - Muraki, Y.

AU - Nagaya, M.

AU - Nishimoto, K.

AU - Ohnishi, K.

AU - Okumura, T.

AU - Omori, K.

AU - Perrott, Y. C.

AU - Rattenbury, N.

AU - Saito, To

AU - Skuljan, L.

AU - Sullivan, D. J.

AU - Suzuki, D.

AU - Suzuki, K.

AU - Sweatman, W. L.

AU - Takino, S.

AU - Tristram, P. J.

AU - Wada, K.

AU - Yock, P. C.M.

AU - Szymański, M. K.

AU - Kubiak, M.

AU - Pietrzyński, G.

AU - Soszyński, I.

AU - Poleski, R.

AU - Ulaczyk, K.

AU - Wyrzykowski, null

AU - Kozłowski, S.

AU - Pietrukowicz, P.

AU - Albrow, M. D.

AU - Bachelet, E.

AU - Batista, V.

AU - Bennett, C. S.

AU - Bowens-Rubin, R.

AU - Brillant, S.

AU - Cassan, A.

AU - Cole, A.

AU - Corrales, E.

AU - Coutures, Ch

AU - Dieters, S.

AU - Dominis Prester, D.

AU - Donatowicz, J.

AU - Fouqué, P.

AU - Greenhill, J.

AU - Kane, S. R.

AU - Menzies, J.

AU - Sahu, K. C.

AU - Wambsganss, J.

AU - Williams, A.

AU - Zub, M.

AU - Allan, A.

AU - Bramich, D. M.

AU - Browne, P.

AU - Clay, N.

AU - Fraser, S.

AU - Horne, K.

AU - Kains, N.

AU - Mottram, C.

AU - Snodgrass, C.

AU - Steele, I.

AU - Tsapras, Y.

AU - Alsubai, K. A.

AU - Bozza, V.

AU - Burgdorf, M. J.

AU - Calchi Novati, S.

AU - Dodds, P.

AU - Dreizler, S.

AU - Finet, F.

AU - Gerner, T.

AU - Glitrup, M.

AU - Grundahl, F.

AU - Hardis, S.

AU - Harpsoe, K.

AU - Hinse, T. C.

AU - Hundertmark, M.

AU - Jorgensen, U. G.

AU - Kerins, E.

AU - Liebig, C.

AU - Maier, G.

AU - Mancini, L.

AU - Mathiasen, M.

AU - Penny, M. T.

AU - Proft, S.

AU - Rahvar, S.

AU - Ricci, D.

AU - Scarpetta, G.

AU - Schäfer, S.

AU - Schönebeck, F.

AU - Skottfelt, J.

AU - Surdej, J.

AU - Southworth, J.

AU - Zimmer, F.

N1 - Work by C.H. was supported by the Creative Research Initiative Program (2009-0081561) of the National Research Foundation of Korea. The MOA experiment was supported by JSPS17340074, JSPS18253002, JSPS20340052, JSPS22403003, and JSPS23340064. The OGLE project has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement No. 246678. Work by B.S.G. and A.G. was supported in part by NSF grant AST-1103471. Work by B.S.G., A.G., R.W.P., and J.C.Y. was supported in part by NASA grant NNX08AF40G. Work by J.C.Y. was supported by a National Science Foundation Graduate Research Fellowship under grant No. 2009068160. C.B.H. acknowledges the support of NSF Graduate Research Fellowship 2011082275. T.S. was supported by the grants JSPS18749004, MEXT19015005, and JSPS20740104. F.F., D.R., and J.S. were supported by the Communauté française de Belgique–Actions de recherche concertées–Académie universitaire Wallonie-Europe.

PY - 2012/5/2

Y1 - 2012/5/2

N2 - We present the analysis of the light curves of nine high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE- 2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/ MOA-2011-BLG-325. For all of the events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For seven events, we measure the Einstein radii and the lens-source relative proper motions. Among them, five events are found to have Einstein radii of less than 0.2 mas, making the lenses very low mass star or brown dwarf candidates. For MOA-2011-BLG-274, especially, the small Einstein radius of θE 0.08 mas combined with the short timescale of t E 2.7days suggests the possibility that the lens is a free-floating planet. For MOA-2009-BLG-174, we measure the lens parallax and thus uniquely determine the physical parameters of the lens. We also find that the measured lens mass of 0.84 M ⊙ is consistent with that of a star blended with the source, suggesting that the blend is likely to be the lens. Although we did not find planetary signals for any of the events, we provide exclusion diagrams showing the confidence levels excluding the existence of a planet as a function of the separation and mass ratio.

AB - We present the analysis of the light curves of nine high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE- 2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/ MOA-2011-BLG-325. For all of the events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For seven events, we measure the Einstein radii and the lens-source relative proper motions. Among them, five events are found to have Einstein radii of less than 0.2 mas, making the lenses very low mass star or brown dwarf candidates. For MOA-2011-BLG-274, especially, the small Einstein radius of θE 0.08 mas combined with the short timescale of t E 2.7days suggests the possibility that the lens is a free-floating planet. For MOA-2009-BLG-174, we measure the lens parallax and thus uniquely determine the physical parameters of the lens. We also find that the measured lens mass of 0.84 M ⊙ is consistent with that of a star blended with the source, suggesting that the blend is likely to be the lens. Although we did not find planetary signals for any of the events, we provide exclusion diagrams showing the confidence levels excluding the existence of a planet as a function of the separation and mass ratio.

UR - http://www.scopus.com/inward/record.url?scp=84860768882&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/751/1/41

DO - 10.1088/0004-637X/751/1/41

M3 - مقالة

SN - 0004-637X

VL - 751

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1

M1 - 41

ER -

Characterizing lenses and lensed stars of high-magnification single-lens gravitational microlensing events with lenses passing over source stars

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