Brown dwarf companions in microlensing binaries detected during the 2016-2018 seasons
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Date
2022-11-08
Open Access Location
Journal Title
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Publisher
EDP Sciences on behalf of the European Southern Observatory
Rights
(c) The author/s
CC BY 4.0
Abstract
Aims. With the aim of finding microlensing binaries containing brown dwarf (BD) companions, we investigate the microlensing survey data collected during the 2016 2018 seasons.
Methods. For this purpose, we first modeled lensing events with light curves exhibiting anomaly features that are likely to be produced by binary lenses. We then sorted out BD companion binary-lens events by applying the criterion that the companion-to-primary mass ratio is q 0.1. With this procedure, we identify six binaries with candidate BD companions: OGLE-2016-BLG-0890L, MOA-2017-BLG-477L, OGLE-2017-BLG-0614L, KMT-2018-BLG-0357L, OGLE-2018-BLG-1489L, and OGLE-2018-BLG-0360L.
Results. We estimated the masses of the binary companions by conducting Bayesian analyses using the observables of the individual lensing events. According to the Bayesian estimation of the lens masses, the probabilities for the lens companions of the events OGLE-2016-BLG-0890, OGLE-2017-BLG-0614, OGLE-2018-BLG-1489, and OGLE-2018-BLG-0360 to be in the BD mass regime are very high with PBD > 80%. For MOA-2017-BLG-477 and KMT-2018-BLG-0357, the probabilities are relatively low with PBD = 61% and 69%, respectively.
Description
Keywords
gravitational lensing, micro – brown dwarfs
Citation
Han C, Ryu YH, Shin IG, Kil Jung Y, Kim D, Hirao Y, Bozza V, Albrow MD, Zang W, Udalski A, Bond IA, Chung SJ, Gould A, Hwang KH, Shvartzvald Y, Yang H, Cha SM, Kim DJ, Kim HW, Kim SL, Lee CU, Lee DJ, Yee JC, Lee Y, Park BG, Pogge RW, Mroz P, Szymanski MK, Skowron J, Poleski R, Soszynski I, Pietrukowicz P, Kozlowski S, Ulaczyk K, Rybicki KA, Iwanek P, Wrona M, Abe F, Barry R, Bennett DP, Bhattacharya A, Fujii H, Fukui A, Ishitani Silva S, Kirikawa R, Kondo I, Koshimoto N, Matsubara Y, Matsumoto S, Miyazaki S, Muraki Y, Okamura A, Olmschenk G, Ranc C, Rattenbury NJ, Satoh Y, Sumi T, Suzuki D, Toda T, Tristram PJ, Vandorou A, Yama H, Itow Y. (2022). Brown dwarf companions in microlensing binaries detected during the 2016 2018 seasons. Astronomy and Astrophysics. 667.