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A possible binary system of a stellar remnant in the high-magnification gravitational microlensing event OGLE-2007-BLG-514
journal contribution
posted on 2023-05-17, 13:32 authored by Miyake, N, Udalski, A, Sumi, T, Bennett, DP, Dong, S, Street, RA, Greenhill, J, Bond, IA, Gould, A, Kubiak, M, Szymanski, MK, Pietrzynski, G, Soszynski, I, Ulaczyk, K, Wyrzykowski, L, Abe, F, Fukui, A, Furusawa, K, Holderness, S, Itow, Y, Korpela, A, Ling, CH, Masuda, K, Matsubara, Y, Muraki, Y, Nagayama, T, Ohnishi, K, Rattenbury, N, Saito, T, Sako, T, Sullivan, DJ, Sweatman, WL, Tristram, PJ, Yock, PCM, Allen, W, Christie, GW, Depoy, DL, Gaudi, BS, Han, C, Lee, C-U, McCormick, J, Monard, B, Natusch, T, Park, B-G, Pogge, RW, Allan, A, Bode, M, Bramich, DM, Clay, N, Dominik, M, Horne, KD, Kains, N, Mottram, C, Snodgrass, C, Steele, I, Tsapras, Y, Albrow, MD, Batista, V, Beaulieu, JP, Brillant, S, Burgdorf, M, Caldwell, JAR, Cassan, A, Andrew ColeAndrew Cole, Cook, KH, Coutures, C, Dieters, S, Prester, DD, Donatowicz, J, Fouque, P, Jorgensen, UG, Kane, S, Kubas, D, Marquette, JB, Martin, R, Menzies, J, Pollard, KR, Sahu, KC, Wambsganss, J, Williams, A, Zub, MWe report the extremely high-magnification (A > 1000) binary microlensing event OGLE-2007-BLG-514. We obtained good coverage around the double peak structure in the light curve via follow-up observations from different observatories. The binary lens model that includes the effects of parallax (known orbital motion of the Earth) and orbital motion of the lens yields a binary lens mass ratio of q = 0.321 ± 0.007 and a projected separation of s = 0.072 ± 0.001 in units of the Einstein radius. The parallax parameters allow us to determine the lens distance DL = 3.11 ± 0.39kpc and total mass ML = 1.40 ± 0.18 M⊙; this leads to the primary and secondary components having masses of M1 = 1.06 ± 0.13 M⊙ and M2 = 0.34 ± 0.04 M⊙, respectively. The parallax model indicates that the binary lens system is likely constructed by the main-sequence stars. On the other hand, we used a Bayesian analysis to estimate probability distributions by the model that includes the effects of xallarap (possible orbital motion of the source around a companion) and parallax (q = 0.270 ± 0.005, s = 0.083 ± 0.001). The primary component of the binary lens is relatively massive, with M1 = 0.9+4.6-0.3 M⊙ and it is at a distance of DL = 2.6+3.8-0.9 kpc. Given the secure mass ratio measurement, the companion mass is therefore M2 = 0.2+1.2-0.1 M⊙. The xallarap model implies that the primary lens is likely a stellar remnant, such as a white dwarf, a neutron star, or a black hole.
History
Publication title
Astrophysical JournalVolume
752Article number
82Number
82Pagination
1-12ISSN
0004-637XDepartment/School
School of Natural SciencesPublisher
Institute of Physics Publishing Ltd.Place of publication
United StatesRights statement
Copyright 2012 The American Astronomical SocietyRepository Status
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