CaltechAUTHORS
Published March 1, 2019 | Version Published + Submitted
Journal Article Open

OGLE-2014-BLG-0962 and a Comparison of Galactic Model Priors to Microlensing Data

Creators

Abstract

OGLE-2014-BLG-0962 (OB140962) is a stellar binary microlensing event that was well covered by observations from the Spitzer satellite as well as ground-based surveys. Modeling yields a unique physical solution: a mid-M+M-dwarf binary with M_(prim) = 0.20 ± 0.01 M☉ and M_(sec) = 0.16 ± 0.01 M☉, with projected separation of 2.0 ± 0.3 au. The lens is only D_(LS) = 0.41 ± 0.06 kpc in front of the source, making OB140962 a bulge lens and the most distant Spitzer binary lens to date. In contrast, because the Einstein radius (θ_E = 0.143 ± 0.007 mas) is unusually small, a standard Bayesian analysis, conducted in the absence of parallax information, would predict a brown dwarf binary. We compare the results of Bayesian analysis using two commonly used Galactic model priors to the measured values for a set of Spitzer lenses. We find all models tested predict lens properties consistent with the Spitzer data. Furthermore, we illustrate the methodology for probing the Galactic distribution of planets by comparing the cumulative distance distribution of the Spitzer two-body lenses to that of the Spitzer single lenses.

Additional Information

© 2019 The American Astronomical Society. Received 2018 May 23; revised 2019 January 15; accepted 2019 January 17; published 2019 February 28. The authors would like to thank John Johnson, Jason Eastman, and other members of the Exolab for providing helpful suggestions and feedback throughout the course of this work. We are grateful to Vinay Kashyap for his statistical guidance. We thank Wei Zhu for contributing the data for the Spitzer single-lens CDF (Figure 12 of Zhu et al. 2017) and for discussions. Y. Shan is supported in part by a Doctoral Postgraduate Scholarship from the Natural Science and Engineering Research Council (NSERC) of Canada. The OGLE project has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to A.U. The OGLE Team thanks Profs. M. Kubiak and G. Pietrzyński for their contribution to the OGLE photometric data set. The MOA project is supported by JSPS KAKENHI grant Nos. JSPS24253004, JSPS26247023, JSPS23340064, JSPS15H00781, and JP16H06287. This research was supported by the I-CORE program of the Planning and Budgeting Committee and the Israel Science Foundation, grant 1829/12. D.M. and A.G. acknowledge support by the U.S.–Israel Binational Science Foundation.

Attached Files

Published - Shan_2019_ApJ_873_30.pdf

Submitted - 1805.09350.pdf

Files

1805.09350.pdf

Files (7.0 MB)

Name Size Download all
md5:42319a32f1746a991ac82a620eb6e907
4.6 MB Preview Download
md5:58dd6d202f8b3f81dfde7e8e298cbb34
2.5 MB Preview Download

Additional details

Additional titles

Alternative title
OGLE-2014-BLG-0962 and the First Statistical Validation of Bayesian Priors for Galactic Microlensing

Identifiers

Eprint ID
92466
Resolver ID
CaltechAUTHORS:20190124-122631813

Related works

Describes
https://arxiv.org/abs/1805.09350 (URL)

Funding

Natural Sciences and Engineering Research Council of Canada (NSERC)
National Science Centre (Poland)
MAESTRO 2014/14/A/ST9/00121
Japan Society for the Promotion of Science (JSPS)
JSPS24253004
Japan Society for the Promotion of Science (JSPS)
JSPS26247023
Japan Society for the Promotion of Science (JSPS)
JSPS23340064
Japan Society for the Promotion of Science (JSPS)
JSPS15H00781
Japan Society for the Promotion of Science (JSPS)
JP16H06287
I-CORE Program of the Planning and Budgeting Committee
Israel Science Foundation
1829/12
Binational Science Foundation (USA-Israel)

Dates

Created
2019-01-25
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)