REANALYSES OF ANOMALOUS GRAVITATIONAL MICROLENSING EVENTS IN THE OGLE-III EARLY WARNING SYSTEM DATABASE WITH COMBINED DATA

Journal Article · Fri May 01 00:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/804/1/38· OSTI ID:22522478

Jeong, J.; Park, H.; Han, C. ^[1]; Gould, A.; Poleski, R. ^[2]; Udalski, A.; Szymański, M. K.; Pietrzyński, G.; Soszyński, I.; Ulaczyk, K.; Wyrzykowski, Ł. ^[3]; Abe, F.; Fukunaga, D.; Itow, Y. ^[4]; Bennett, D. P. ^[5]; Bond, I. A. ^[6]; Botzler, C. S.; Freeman, M. ^[7]; Fukui, A. ^[8]; Koshimoto, N. ^[9] ; others, and

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1. Department of Physics, Institute for Astrophysics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)
2. Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States)
3. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)
4. Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, 464-8601 (Japan)
5. Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670 (United States)
6. Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland (New Zealand)
7. Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001 (New Zealand)
8. Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan)
9. Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan)

We reanalyze microlensing events in the published list of anomalous events that were observed from the Optical Gravitational Lensing Experiment (OGLE) lensing survey conducted during the 2004–2008 period. In order to check the existence of possible degenerate solutions and extract extra information, we conduct analyses based on combined data from other survey and follow-up observation and consider higher-order effects. Among the analyzed events, we present analyses of eight events for which either new solutions are identified or additional information is obtained. We find that the previous binary-source interpretations of five events are better interpreted by binary-lens models. These events include OGLE-2006-BLG-238, OGLE-2007-BLG-159, OGLE-2007-BLG-491, OGLE-2008-BLG-143, and OGLE-2008-BLG-210. With additional data covering caustic crossings, we detect finite-source effects for six events including OGLE-2006-BLG-215, OGLE-2006-BLG-238, OGLE-2006-BLG-450, OGLE-2008-BLG-143, OGLE-2008-BLG-210, and OGLE-2008-BLG-513. Among them, we are able to measure the Einstein radii of three events for which multi-band data are available. These events are OGLE-2006-BLG-238, OGLE-2008-BLG-210, and OGLE-2008-BLG-513. For OGLE-2008-BLG-143, we detect higher-order effects induced by the changes of the observer’s position caused by the orbital motion of the Earth around the Sun. In addition, we present degenerate solutions resulting from the known close/wide or ecliptic degeneracy. Finally, we note that the masses of the binary companions of the lenses of OGLE-2006-BLG-450 and OGLE-2008-BLG-210 are in the brown-dwarf regime.

• OSTI ID: 22522478
• Journal Information: Astrophysical Journal, Vol. 804, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALARM SYSTEMS
DWARF STARS
ECLIPSE
GRAVITATIONAL LENSES
MASS
SUN