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Mass Measurements of Isolated Objects from Space-based Microlensing

Zhu, Wei and Calchi Novati, S. and Beichman, C. and Carey, S. (2016) Mass Measurements of Isolated Objects from Space-based Microlensing. Astrophysical Journal, 825 (1). Art. No. 60. ISSN 0004-637X.

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We report on the mass and distance measurements of two single-lens events from the 2015 Spitzer microlensing campaign. With both finite-source effect and microlens parallax measurements, we find that the lens of OGLE-2015-BLG-1268 is very likely a brown dwarf (BD). Assuming that the source star lies behind the same amount of dust as the Bulge red clump, we find the lens is a 45 ± 7 M_J BD at 5.9 ± 1.0 kpc. The lens of of the second event, OGLE-2015-BLG-0763, is a 0.50 ± 0.04 M_M☉ star at 6.9 ± 1.0 kpc. We show that the probability to definitively measure the mass of isolated microlenses is dramatically increased once simultaneous ground- and space-based observations are conducted.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Zhu, Wei0000-0003-4027-4711
Calchi Novati, S.0000-0002-7669-1069
Beichman, C.0000-0002-5627-5471
Carey, S.0000-0002-0221-6871
Additional Information:© 2016 American Astronomical Society. Received 2015 October 13; accepted 2016 April 21; published 2016 June 27. Work by WZ, SCN and AG was supported by JPL grant 1500811. WZ and AG also acknowledge support by NSF grant AST-1516842. Work by JCY was performed under contract with the California Institute of Technology (Caltech)/Jet Propulsion Laboratory (JPL) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. The Spitzer Team thanks Christopher S. Kochanek for graciously trading us his allocated observing time on the CTIO 1.3 m during the Spitzer campaign. The OGLE project has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to au. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Work by CH was supported by Creative Research Initiative Program (2009-0081561) of National Research Foundation of Korea. This research has made the use of the KMTNet telescopes operated by the Korea Astronomy and Space Science Institute (KASI), and was supported by KASI grant 2016-1-832-01. This work makes use of observations from the LCOGT network, which includes three SUPAscopes owned by the University of St Andrews. The RoboNet programme is an LCOGT Key Project using time allocations from the University of St Andrews, LCOGT and the University of Heidelberg together with time on the Liverpool Telescope through the Science and Technology Facilities Council (STFC), UK. This research has made use of the LCOGT Archive, which is operated by the California Institute of Technology, under contract with the Las Cumbres Observatory. KH acknowledges support from STFC grant ST/M001296/1. This project is partly supported by the Strategic Priority Research Program "The Emergence of Cosmological Structures" of the Chinese Academy of Sciences, Grant No. XDB09000000 (SM and SD). MPGH acknowledges support from the Villum Foundation. NP acknowledges funding by the Gemini-Conicyt Fund, allocated to the project No. 32120036. Based on data collected by MiNDSTEp with the Danish 1.54 m telescope at the ESO La Silla observatory. Operation of the Danish 1.54 m telescope at ESOs La Silla observatory was supported by The Danish Council for Independent Research, Natural Sciences, and by Centre for Star and Planet Formation. The MiNDSTEp monitoring campaign is powered by ARTEMiS (Automated Terrestrial Exoplanet Microlensing Search, Dominik et al. 2008). DMB acknowledges support from NPRP grant # X-019-1-006 from the Qatar National Research Fund (a member of Qatar Foundation). GD acknowledges Regione Campania for support from POR-FSE Campania 2014-2020. OW and JS acknowledge support from the Communauté francaise de Belgique' Actions de recherche concertées' Académie universitaire Wallonie-Europe.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
National Science Centre (Poland)MAESTRO 2014/14/A/ST9/00121
National Research Foundation of Korea2009-0081561
Korea Astronomy and Space Science Institute (KASI)2016-1-832-01
Las Cumbres ObservatoryUNSPECIFIED
Science and Technology Facilities Council (STFC)ST/M001296/1
Chinese Academy of SciencesXDB09000000
Villum FoundationUNSPECIFIED
Gemini-Conicyt Fund32120036
Danish Council for Independent Research-Natural SciencesUNSPECIFIED
Centre for Star and Planet FormationUNSPECIFIED
Qatar National Research FundX-019-1-006
Regione CampaniaPOR-FSE Campania 2014–2020
Communauté francaise de Belgique' Actions de recherche concertées' Académie universitaire Wallonie-EuropeUNSPECIFIED
Subject Keywords:brown dwarfs; gravitational lensing: micro; stars: fundamental parameters
Issue or Number:1
Record Number:CaltechAUTHORS:20160930-144350038
Persistent URL:
Official Citation:Wei Zhu (祝伟) et al 2016 ApJ 825 60
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:70717
Deposited By: Ruth Sustaita
Deposited On:30 Sep 2016 22:46
Last Modified:24 Feb 2020 10:30

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