A POSSIBLE BINARY SYSTEM OF A STELLAR REMNANT IN THE HIGH-MAGNIFICATION GRAVITATIONAL MICROLENSING EVENT OGLE-2007-BLG-514 Academic Article uri icon

abstract

  • We 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 M 1 = 1.06 0.13 M and M 2 = 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 M 1 = 0.9+4.6-0.3 M and it is at a distance of D L = 2.6+3.8-0.9kpc. Given the secure mass ratio measurement, the companion mass is therefore M 2 = 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. 2012. The American Astronomical Society. All rights reserved.

published proceedings

  • The Astrophysical Journal

altmetric score

  • 0.25

author list (cited authors)

  • Miyake, N., Udalski, A., Sumi, T., Bennett, D. P., Dong, S., Street, R. A., ... Zub, M.

citation count

  • 14

complete list of authors

  • Miyake, N||Udalski, A||Sumi, T||Bennett, DP||Dong, S||Street, RA||Greenhill, J||Bond, IA||Gould, A||Kubiak, M||Szymański, MK||Pietrzyński, G||Soszyński, 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, To||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||Cole, A||Cook, KH||Coutures, Ch||Dieters, S||Prester, D Dominis||Donatowicz, J||Fouqué, P||Jorgensen, UG||Kane, S||Kubas, D||Marquette, JB||Martin, R||Menzies, J||Pollard, KR||Sahu, KC||Wambsganss, J||Williams, A||Zub, M

publication date

  • June 2012