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Journal Paper

전체
Ground-based Parallax Confirmed by Spitzer: Binary Microlensing Event MOA-2015-BLG-020 SCI
  • Tianshu Wang;Wei Zhu;Shude Mao;I. A. Bond;Andrew P. Gould;A. Udalski;T. Sumi;V. Bozza;C. Ranc;A. Cassan;J. C. Yee;C. Han;F. Abe;Y. Asakura;R. Barry;D. P. Bennett;A. Bhattacharya;M. Donachie;P. Evans;A. Fukui;Y. Hirao;Y. Itow;K. Kawasaki;N. Koshimoto;M. C. A. Li;C. H. Ling;K. Masuda;Y. Matsubara;S. Miyazaki;Y. Muraki;M. Nagakane;K. Ohnishi;N. Rattenbury;To. Saito;A. Sharan;H. Shibai;D. J. Sullivan;D. Suzuki;P. J. Tristram;T. Yamada;A. Yonehara;S. KozŁowski;P. Mroz;M. Pawlak;P. Pietrukowicz;R. Poleski;J. Skowron;I. Soszy?ski;M. K. Szyma?ski;K. Ulaczyk;C. Beichman;G. Bryden;S. Calchi Novati;S. Carey;M. Fausnaugh;B. S. Gaudi;C. B. Henderson;Y. Shvartzvald;B. Wibking;M. D. Albrow;정선주;K.-H. Hwang;Y. K. Jung;류윤현;I.-G. Shin;차상목;김동진;김현우;김승리;이충욱;이용석;박병곤;R. W. Pogge;R. A. Street;Y. Tsapras;M. Hundertmark;E. Bachelet;M. Dominik;K. Horne;R. Figuera Jaimes;J. Wambsganss;D. M. Bramich;R. Schmidt;C. Snodgrass;I. A. Steele;J. Menzies
  • 2017-08-20
  • THE ASTROPHYSICAL JOURNAL 845 2 : 129-1~129-11
We present the analysis of the binary gravitational microlensing event MOA-2015-BLG-020. The event has a fairly long timescale (∼63 days) and thus the light curve deviates significantly from the lensing model that is based on the rectilinear lens-source relative motion. This enables us to measure the microlensing parallax through the annual parallax effect. The microlensing parallax parameters constrained by the ground-based data are confirmed by the Spitzer observations through the satellite parallax method. By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing, the physical parameters of the lens are determined. It is found that the binary lens is composed of two dwarf stars with masses M1 = 0.606 ± 0.028 M⊙ and M2 = 0.125 ± 0.006 M⊙ in the Galactic disk. Assuming that the source star is at the same distance as the bulge red clump stars, we find the lens is at a distance DL = 2.44 ± 0.10 kpc. We also provide a summary and short discussion of all of the published microlensing events in which the annual parallax effect is confirmed by other independent observations.