Binary microlensing events from the MACHO Project

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dc.contributor.authorAlcock, C
dc.contributor.authorAllsman, RA
dc.contributor.authorAlves, D
dc.contributor.authorAxelrod, TS
dc.contributor.authorBaines, D
dc.contributor.authorBecker, AC
dc.contributor.authorBennett, DP
dc.contributor.authorBourke, A
dc.contributor.authorBrakel, A
dc.contributor.authorCook, KH
dc.contributor.authorCrook, B
dc.contributor.authorCrouch, A
dc.contributor.authorDan, J
dc.contributor.authorDrake, AJ
dc.contributor.authorFragile, PC
dc.contributor.authorFreeman, KC
dc.contributor.authorGal-Yam, A
dc.contributor.authorGeha, M
dc.contributor.authorGray, J
dc.contributor.authorGriest, K
dc.contributor.authorGurtierrez, A
dc.contributor.authorHeller, A
dc.contributor.authorHoward, J
dc.contributor.authorJohnson, BR
dc.contributor.authorKaspi, S
dc.contributor.authorKeane, M
dc.contributor.authorKovo, O
dc.contributor.authorLeach, C
dc.contributor.authorLeach, T
dc.contributor.authorLeibowitz, EM
dc.contributor.authorLehner, MJ
dc.contributor.authorLipkin, Y
dc.contributor.authorMaoz, D
dc.contributor.authorMarshall, L
dc.contributor.authorMcDowell, D
dc.contributor.authorMcKeown, S
dc.contributor.authorMendelson, H
dc.contributor.authorMessenger, B
dc.contributor.authorMinniti, D
dc.contributor.authorNelson, C
dc.contributor.authorPeterson, BA
dc.contributor.authorPopowski, P
dc.contributor.authorPozza, E
dc.contributor.authorPurcell, P
dc.contributor.authorPratt, MR
dc.contributor.authorQuinn, J
dc.contributor.authorQuinn, PJ
dc.contributor.authorRhie, SH
dc.contributor.authorRodgers, AW
dc.contributor.authorSalmon, A
dc.contributor.authorShemmer, O
dc.contributor.authorStetson, P
dc.contributor.authorStubbs, CW
dc.contributor.authorSutherland, W
dc.contributor.authorThomson, S
dc.contributor.authorTomaney, A
dc.contributor.authorVandehei, T
dc.contributor.authorWalker, A
dc.contributor.authorWard, K
dc.contributor.authorWyper, G
dc.date.accessioned2025-01-21T01:31:11Z
dc.date.available2025-01-21T01:31:11Z
dc.date.issued2000
dc.description.abstractWe present the light curves of 21 gravitational microlensing events from the first six years of the MACHO Project gravitational microlensing survey that are likely examples of lensing by binary systems. These events were manually selected from a total sample of similar to 350 candidate microlensing events that were either detected by the MACHO Alert System or discovered through retrospective analyses of the MACHO database. At least 14 of these 21 events exhibit strong (caustic) features, and four of the events are well fit with lensing by large mass ratio (brown dwarf or planetary) systems, although these fits are not necessarily unique. The total binary event rate is roughly consistent with predictions based upon our knowledge of the properties of binary stars, but a precise comparison cannot be made without a determination of our binary lens event detection efficiency. Toward the Galactic bulge, we find a ratio of caustic crossing to noncaustic crossing binary lensing events of 12:4, excluding one event for which we present two fits. This suggests significant incompleteness in our ability to detect and characterize noncaustic crossing binary lensing. The distribution of mass ratios, N(q), for these binary lenses appears relatively flat. We are also able to reliably measure source-face crossing times in four of the bulge caustic crossing events, and recover from them a distribution of lens proper motions, masses, and distances consistent with a population of Galactic bulge lenses at a distance of 7 +/- 1 kpc. This analysis yields two systems with companions of similar to 0.05 M..
dc.fuente.origenWOS
dc.identifier.eissn1538-4357
dc.identifier.issn0004-637X
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/97005
dc.identifier.wosidWOS:000089694300028
dc.issue.numero1
dc.language.isoen
dc.pagina.final297
dc.pagina.inicio270
dc.revistaAstrophysical journal
dc.rightsacceso restringido
dc.subjectbinaries : general
dc.subjectdark matter
dc.subjectgravitational lensing
dc.subjectstars : low-mass
dc.subjectbrown dwarfs
dc.subject.ods13 Climate Action
dc.subject.odspa13 Acción por el clima
dc.titleBinary microlensing events from the MACHO Project
dc.typeartículo
dc.volumen541
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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