Combined analysis of the binary lens caustic-crossing event MACHO 98-SMC-1

被引:104
作者
Afonso, C [1 ]
Alard, C
Albert, JN
Andersen, J
Ansari, R
Aubourg, E
Bareyre, P
Bauer, F
Beaulieu, JP
Bouquet, A
Char, S
Charlot, X
Couchot, F
Coutures, C
Derue, F
Ferlet, R
Glicenstein, JF
Goldman, B
Gould, A
Graff, D
Gros, M
Haissinski, J
Hamilton, JC
Hardin, D
de Kat, J
Kim, A
Lasserre, T
Lesquoy, E
Loup, C
Magneville, C
Marquette, JB
Maurice, E
Milsztajn, A
Moniez, M
Palanque-Delabrouille, N
Perdereau, O
Prévot, L
Regnault, N
Rich, J
Spiro, M
Vidal-Madjar, A
Vigroux, L
Zylberajch, S
Alcock, C
Allsman, RA
Alves, D
Axelrod, TS
Becker, AC
Cook, KH
Drake, AJ
机构
[1] CEA, DSM, DAPNIA, Ctr Etud Saclay, F-91191 Gif Sur Yvette, France
[2] DASGAL, F-75014 Paris, France
[3] Univ Paris 11, CNRS, Lab Accelerateur Lineaire, IN2P3, F-91405 Orsay, France
[4] Univ Copenhagen, Astron Observ, DK-2100 Copenhagen, Denmark
[5] Coll France, CNRS, IN2P3, F-75231 Paris, France
[6] CNRS, INSU, Inst Astrophys Paris, F-75014 Paris, France
[7] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands
[8] Univ La Serena, Fac Ciencias, Dept Fis, La Serena, Chile
[9] Univ Chile, Dept Astron, Santiago, Chile
[10] European So Observ, Santiago 19, Chile
[11] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA
[12] Observ Marseille, F-13248 Marseille 04, France
[13] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA
[14] Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA
[15] Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia
[16] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA
[17] Space Telescope Sci Inst, Baltimore, MD 21218 USA
[18] Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia
[19] Univ Washington, Dept Astron, Seattle, WA 98195 USA
[20] Univ Washington, Dept Phys, Seattle, WA 98195 USA
[21] Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA
[22] Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA
[23] Max Planck Inst Astrophys, D-85740 Garching, Germany
[24] Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England
[25] Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile
[26] MIT, Ctr Space Res, Cambridge, MA 02139 USA
[27] European So Observ, D-85748 Garching, Germany
[28] Natl Res Council Canada, Victoria, BC V8X 4M6, Canada
[29] Univ Oxford, Dept Phys, Oxford OX1 3RH, England
[30] Univ Minnesota, Tate Lab Phys, Minneapolis, MN 55455 USA
[31] Univ Warsaw Observ, PL-00478 Warsaw, Poland
[32] Princeton Univ Observ, Princeton, NJ 08544 USA
[33] Univ Canterbury, Dept Phys & Astron, Christchurch 1, New Zealand
[34] S African Astron Observ, ZA-7935 Cape Town, South Africa
[35] Univ Tasmania, Dept Phys, Hobart, Tas 7001, Australia
[36] Perth Observ, Perth, WA 6076, Australia
关键词
astrometry; dark matter; gravitational lensing; Magellanic Clouds;
D O I
10.1086/308561
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We fit the data for the binary lens microlensing event MACHO 98-SMC-1 from five different microlensing collaborations and find two distinct solutions characterized by binary separation d and mass ratio q: (d, q) = (0.54, 0.50) and (d, q) = (3.65, 0.36), where d is in units of the Einstein radius. However, the relative proper motion of the lens is very similar in the two solutions, 1.30 km s(-1) kpc(-1) and 1.48 km s(-1) kpc(-1), thus confirming that the lens is in the Small Magellanic Cloud. The close binary can be either rotating or approximately static but the wide binary must be rotating at close to its maximum allowed rate to be consistent with all the data. We measure limb-darkening coefficients for five bands ranging from I to V. As expected, these progressively decrease with rising wavelength. This is the first measurement of limb darkening for a metal-poor A star.
引用
收藏
页码:340 / 352
页数:13
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