TY - JOUR
T1 - Microlensing binaries with candidate brown dwarf companions
AU - The μFUN Collaboration
AU - The OGLE collaboration
AU - The MOA collaboration
AU - The RoboNet Collaboration
AU - The MiNDSTEp consortium
AU - The PLANET collaboration
AU - Shin, I.-G.
AU - Han, C.
AU - Gould, Andrew
AU - Udalski, A.
AU - Sumi, T.
AU - Dominik, M.
AU - Beaulieu, J.-P.
AU - Tsapras, Y.
AU - Bozza, V.
AU - Szymański, M. K.
AU - Kubiak, M.
AU - Soszyński, I.
AU - Pietrzyński, G.
AU - Poleski, R.
AU - Ulaczyk, K.
AU - Pietrukowicz, P.
AU - Kozłowski, S.
AU - Skowron, J.
AU - Wyrzykowski, Ł.
AU - Abe, F.
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 - Lee, C.-U.
AU - Bajek, D.
AU - Fang, X.-S.
AU - Gu, C.-H.
AU - Zimmer, F.
AU - Cook, K. H.
AU - Martin, R.
AU - Williams, A.
PY - 2012/12/1
Y1 - 2012/12/1
N2 - Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing events discovered during the 2004–2011 observation seasons. Based on the low mass ratio criterion of q < 0.2, we found seven candidate events: OGLE-2004-BLG-035, OGLE-2004-BLG-039, OGLE-2007-BLG-006, OGLE-2007-BLG-399/MOA-2007-BLG-334, MOA-2011-BLG-104/OGLE-2011-BLG-0172, MOA-2011-BLG-149, and MOA-201-BLG-278/OGLE-2011-BLG-012N. Among them, we are able to confirm that the companions of the lenses of MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149 are brown dwarfs by determining the mass of the lens based on the simultaneous measurement of the Einstein radius and the lens parallax. The measured masses of the brown dwarf companions are 0.02 ± 0.01 M☉ and 0.019 ± 0.002 M☉ for MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149, respectively, and both companions are orbiting low-mass M dwarf host stars. More microlensing brown dwarfs are expected to be detected as the number of lensing events with well-covered light curves increases with new-generation searches.
AB - Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing events discovered during the 2004–2011 observation seasons. Based on the low mass ratio criterion of q < 0.2, we found seven candidate events: OGLE-2004-BLG-035, OGLE-2004-BLG-039, OGLE-2007-BLG-006, OGLE-2007-BLG-399/MOA-2007-BLG-334, MOA-2011-BLG-104/OGLE-2011-BLG-0172, MOA-2011-BLG-149, and MOA-201-BLG-278/OGLE-2011-BLG-012N. Among them, we are able to confirm that the companions of the lenses of MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149 are brown dwarfs by determining the mass of the lens based on the simultaneous measurement of the Einstein radius and the lens parallax. The measured masses of the brown dwarf companions are 0.02 ± 0.01 M☉ and 0.019 ± 0.002 M☉ for MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149, respectively, and both companions are orbiting low-mass M dwarf host stars. More microlensing brown dwarfs are expected to be detected as the number of lensing events with well-covered light curves increases with new-generation searches.
KW - binaries: general
KW - brown dwarfs
KW - gravitational lensing: micro
UR - http://www.scopus.com/inward/record.url?scp=84870261462&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/760/2/116
DO - 10.1088/0004-637X/760/2/116
M3 - Article
AN - SCOPUS:84870261462
SN - 0004-637X
VL - 760
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 116
ER -