Microlensing Binaries Discovered through High-magnification Channel

I.-G Shin; A. Gould; J.-Y Choi; S.Y. Park; T. Sumi; A. Udalski; J.-P Beaulieu; M. Dominik; W. Allen; Uffe Gråe Jørgensen; Kennet Bomann West Harpsøe; Jesper Fælling Skottfelt

doi:10.1088/0004-637X/746/2/127

Microlensing Binaries Discovered through High-magnification Channel

I.-G Shin, A. Gould, J.-Y Choi, S.Y. Park, T. Sumi, A. Udalski, J.-P Beaulieu, M. Dominik, W. Allen, Uffe Gråe Jørgensen, Kennet Bomann West Harpsøe, Jesper Fælling Skottfelt

Astrofysik og Planetforskning

13 Citationer (Scopus)

Abstract

Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a 3σ confidence level for three events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretical prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is q ∼ 0.1, making the companion of the lens a strong brown dwarf candidate.

Originalsprog	Engelsk
Tidsskrift	Astrophysical Journal
Vol/bind	746
Udgave nummer	2
Sider (fra-til)	127
ISSN	0004-637X
DOI	https://doi.org/10.1088/0004-637X/746/2/127
Status	Udgivet - 20 feb. 2012

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10.1088/0004-637X/746/2/127

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title = "Microlensing Binaries Discovered through High-magnification Channel",

abstract = "Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a 3σ confidence level for three events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretical prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is q ∼ 0.1, making the companion of the lens a strong brown dwarf candidate.",

author = "I.-G Shin and A. Gould and J.-Y Choi and S.Y. Park and T. Sumi and A. Udalski and J.-P Beaulieu and M. Dominik and W. Allen and J{\o}rgensen, {Uffe Gr{\aa}e} and Harps{\o}e, {Kennet Bomann West} and Skottfelt, {Jesper F{\ae}lling}",

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T1 - Microlensing Binaries Discovered through High-magnification Channel

AU - Shin, I.-G

AU - Gould, A.

AU - Choi, J.-Y

AU - Park, S.Y.

AU - Sumi, T.

AU - Udalski, A.

AU - Beaulieu, J.-P

AU - Dominik, M.

AU - Allen, W.

AU - Jørgensen, Uffe Gråe

AU - Harpsøe, Kennet Bomann West

AU - Skottfelt, Jesper Fælling

PY - 2012/2/20

Y1 - 2012/2/20

N2 - Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a 3σ confidence level for three events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretical prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is q ∼ 0.1, making the companion of the lens a strong brown dwarf candidate.

AB - Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a 3σ confidence level for three events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretical prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is q ∼ 0.1, making the companion of the lens a strong brown dwarf candidate.

U2 - 10.1088/0004-637X/746/2/127

DO - 10.1088/0004-637X/746/2/127

M3 - Journal article

SN - 0004-637X

VL - 746

SP - 127

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

ER -

Microlensing Binaries Discovered through High-magnification Channel

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