Binary Microlensing Events from the MACHO Project
Alcock, Charles; Allsman, Robyn; Alves, David R; Axelrod, Tim; Baines, D; Becker, Andrew C; Bennett, D P; Bourke, A; Brakel, A; Cook, Kem H; Crook, B; Crouch, A; Dan, J; Drake, Andrew John; Fragile, P C; Freeman, Kenneth; Gal-Yam, Avishay; Geha, M; Gray, J; Griest, K; Gurtierrez, A; Heller, A; Howard, Judith A K; Johnson, B Ronald; Kaspi, S; Keane, Michael Andrew; Kovo, O; Leach, C; Leach, T; Leibowitz, E; Lehner, M J; Lipkin, Y; Maoz, D; Marshall, S L; Mcdowell, D; McKeown, S; Mendelson, H; Messenger, B; Minniti, Dante; Nelson, C A; Peterson, Bruce; Popowski, P; Pozza, E; Purcell, P; Pratt, M; Quinn, J M W; Quinn, Peter J; Rhie, S.; Rodgers, Alexander; Salmon, A; Shemmer, Ohad; Stetson, Peter B; Stubbs, Christopher W; Sutherland, William J; Thomson, S; Tomaney, A B; Vandehei, T; Walker, A; Ward, K; Wyper, G
Description
We 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 ∼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...[Show more]
dc.contributor.author | Alcock, Charles | |
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dc.contributor.author | Allsman, Robyn | |
dc.contributor.author | Alves, David R | |
dc.contributor.author | Axelrod, Tim | |
dc.contributor.author | Baines, D | |
dc.contributor.author | Becker, Andrew C | |
dc.contributor.author | Bennett, D P | |
dc.contributor.author | Bourke, A | |
dc.contributor.author | Brakel, A | |
dc.contributor.author | Cook, Kem H | |
dc.contributor.author | Crook, B | |
dc.contributor.author | Crouch, A | |
dc.contributor.author | Dan, J | |
dc.contributor.author | Drake, Andrew John | |
dc.contributor.author | Fragile, P C | |
dc.contributor.author | Freeman, Kenneth | |
dc.contributor.author | Gal-Yam, Avishay | |
dc.contributor.author | Geha, M | |
dc.contributor.author | Gray, J | |
dc.contributor.author | Griest, K | |
dc.contributor.author | Gurtierrez, A | |
dc.contributor.author | Heller, A | |
dc.contributor.author | Howard, Judith A K | |
dc.contributor.author | Johnson, B Ronald | |
dc.contributor.author | Kaspi, S | |
dc.contributor.author | Keane, Michael Andrew | |
dc.contributor.author | Kovo, O | |
dc.contributor.author | Leach, C | |
dc.contributor.author | Leach, T | |
dc.contributor.author | Leibowitz, E | |
dc.contributor.author | Lehner, M J | |
dc.contributor.author | Lipkin, Y | |
dc.contributor.author | Maoz, D | |
dc.contributor.author | Marshall, S L | |
dc.contributor.author | Mcdowell, D | |
dc.contributor.author | McKeown, S | |
dc.contributor.author | Mendelson, H | |
dc.contributor.author | Messenger, B | |
dc.contributor.author | Minniti, Dante | |
dc.contributor.author | Nelson, C A | |
dc.contributor.author | Peterson, Bruce | |
dc.contributor.author | Popowski, P | |
dc.contributor.author | Pozza, E | |
dc.contributor.author | Purcell, P | |
dc.contributor.author | Pratt, M | |
dc.contributor.author | Quinn, J M W | |
dc.contributor.author | Quinn, Peter J | |
dc.contributor.author | Rhie, S. | |
dc.contributor.author | Rodgers, Alexander | |
dc.contributor.author | Salmon, A | |
dc.contributor.author | Shemmer, Ohad | |
dc.contributor.author | Stetson, Peter B | |
dc.contributor.author | Stubbs, Christopher W | |
dc.contributor.author | Sutherland, William J | |
dc.contributor.author | Thomson, S | |
dc.contributor.author | Tomaney, A B | |
dc.contributor.author | Vandehei, T | |
dc.contributor.author | Walker, A | |
dc.contributor.author | Ward, K | |
dc.contributor.author | Wyper, G | |
dc.date.accessioned | 2015-12-13T23:20:03Z | |
dc.date.available | 2015-12-13T23:20:03Z | |
dc.identifier.issn | 0004-637X | |
dc.identifier.uri | http://hdl.handle.net/1885/90541 | |
dc.description.abstract | We 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 ∼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 non-caustic 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 ∼0.05 M⊙. | |
dc.publisher | IOP Publishing | |
dc.source | Astrophysical Journal, The | |
dc.subject | Keywords: Binaries: general; Dark matter; Gravitational lensing; Stars: low-mass, brown dwarfs | |
dc.title | Binary Microlensing Events from the MACHO Project | |
dc.type | Journal article | |
local.description.notes | Imported from ARIES | |
local.description.refereed | Yes | |
local.identifier.citationvolume | 541 | |
dc.date.issued | 2000 | |
local.identifier.absfor | 020110 - Stellar Astronomy and Planetary Systems | |
local.identifier.ariespublication | MigratedxPub20927 | |
local.type.status | Published Version | |
local.contributor.affiliation | Alcock, Charles, Lawrence Livermore National Laboratory | |
local.contributor.affiliation | Allsman, Robyn, Administrative Division, ANU | |
local.contributor.affiliation | Alves, David R, Space Telescope Science Institute | |
local.contributor.affiliation | Axelrod, Tim, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Baines, D, Canberra Astronomical Society | |
local.contributor.affiliation | Becker, Andrew C, University of Washington | |
local.contributor.affiliation | Bennett, D P, University of Notre Dame | |
local.contributor.affiliation | Bourke, A, Monash University | |
local.contributor.affiliation | Brakel, A, Canberra Astronomical Society | |
local.contributor.affiliation | Cook, Kem H, Lawrence Livermore National Laboratory | |
local.contributor.affiliation | Crook, B, Canberra Astronomical Society | |
local.contributor.affiliation | Crouch, A, Monash University | |
local.contributor.affiliation | Dan, J, Tel Aviv University | |
local.contributor.affiliation | Drake, Andrew John, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Fragile, P C, University of Notre Dame | |
local.contributor.affiliation | Freeman, Kenneth, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Gal-Yam, Avishay, California Institute of Technology | |
local.contributor.affiliation | Geha, M, Lawrence Livermore National Laboratory | |
local.contributor.affiliation | Gray, J, Monash University | |
local.contributor.affiliation | Griest, K, University of California | |
local.contributor.affiliation | Gurtierrez, A, Canberra Astronomical Society | |
local.contributor.affiliation | Heller, A, Tel Aviv University | |
local.contributor.affiliation | Howard, Judith A K, University of Durham | |
local.contributor.affiliation | Johnson, B Ronald, University of Minnesota | |
local.contributor.affiliation | Kaspi, S, Tel Aviv University | |
local.contributor.affiliation | Keane, Michael Andrew, Queensland University of Technology | |
local.contributor.affiliation | Kovo, O, Tel Aviv University | |
local.contributor.affiliation | Leach, C, Canberra Astronomical Society | |
local.contributor.affiliation | Leach, T, Canberra Astronomical Society | |
local.contributor.affiliation | Leibowitz, E, Tel Aviv University | |
local.contributor.affiliation | Lehner, M J, University of Pennsylvania | |
local.contributor.affiliation | Lipkin, Y, Tel Aviv University | |
local.contributor.affiliation | Maoz, D, Tel Aviv University | |
local.contributor.affiliation | Marshall, S L, Kavli Institute for Particle Astrophysics and Cosmology/Stanford University | |
local.contributor.affiliation | Mcdowell, D, Canberra Astronomical Society | |
local.contributor.affiliation | McKeown, S, Canberra Astronomical Society | |
local.contributor.affiliation | Mendelson, H, Tel Aviv University | |
local.contributor.affiliation | Messenger, B, Monash University | |
local.contributor.affiliation | Minniti, Dante, Lawrence Livermore National Laboratory | |
local.contributor.affiliation | Nelson, C A, Lawrence Livermore National Laboratory | |
local.contributor.affiliation | Peterson, Bruce, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Popowski, P, Lawrence Livermore National Laboratory | |
local.contributor.affiliation | Pozza, E, Canberra Astronomical Society | |
local.contributor.affiliation | Purcell, P, Canberra Astronomical Society | |
local.contributor.affiliation | Pratt, M, LIGO Massachusetts Institute of Technology | |
local.contributor.affiliation | Quinn, J M W, St Vincent's Hospital Melbourne | |
local.contributor.affiliation | Quinn, Peter J, European Southern Observatory | |
local.contributor.affiliation | Rhie, S., University of Notre Dame | |
local.contributor.affiliation | Rodgers, Alexander, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Salmon, A, Canberra Astronomical Society | |
local.contributor.affiliation | Shemmer, Ohad, Tel Aviv University, Wise Observatory | |
local.contributor.affiliation | Stetson, Peter B, National Research Council of Canada | |
local.contributor.affiliation | Stubbs, Christopher W, University of Washington | |
local.contributor.affiliation | Sutherland, William J, University of Cambridge | |
local.contributor.affiliation | Thomson, S, Monash University | |
local.contributor.affiliation | Tomaney, A B, University of Washington | |
local.contributor.affiliation | Vandehei, T, University of California | |
local.contributor.affiliation | Walker, A, National Optical Astronomy Observatories | |
local.contributor.affiliation | Ward, K, Goulburn Broken Catchment Management Authority | |
local.contributor.affiliation | Wyper, G, Canberra Astronomical Society | |
local.bibliographicCitation.startpage | 270 | |
local.bibliographicCitation.lastpage | 297 | |
dc.date.updated | 2015-12-12T09:01:48Z | |
local.identifier.scopusID | 2-s2.0-0034692202 | |
Collections | ANU Research Publications |
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