Abstract
The first 22 years of a search for exoplanets by gravitational microlensing that is being conducted by the Japan/NZ collaboration known as MOA are described. A range of techniques that was developed in association with other international collaborations is outlined, and these are typified by a chronological sequence of examples from the published literature. The detection of exoplanets in gravitational microlensing events of high and moderately high magnification is emphasized. Physical descriptions of these processes are given. Evidence for free-floating planets is also presented, and recent results on the mass-radius distribution of planets and on the planetary mass-function are given. Current plans for the near-term future of the international microlensing community are described, and also for the more distant future. The latter includes a survey of exoplanets that will be conducted by the WFIRST space telescope in the coming decade. Brief remarks are also made on early and current searches for dark matter by MOA.
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References
Abe F, Bond IA, Carter BS et al (1999) Observation of the halo of the edge-on galaxy IC5249. AJ 118:261–272. https://doi.org/10.1086/300907
Abe F, Airey C, Barnard E et al (2013) Extending the planetary mass function to earth mass by gravitational microlensing at moderately high magnification. MNRAS 431:2975–2985. https://doi.org/10.1093/mnras/stt318
Alcock C, Akerlof CW, Allsman RA et al (1993) Possible gravitational microlensing of a star in the large Magellanic cloud. Nature 365:621–623. https://doi.org/10.1038/365621a0
Alcock C, Allsman RA, Axelrod TS et al (1995) Probable gravitational microlensing towards the galactic bulge. ApJ 445:133–139. https://doi.org/10.1086/175678
Aubourg E, Bareyre P, Brehin S et al (1993) Evidence for gravitational microlensing by dark objects in the galactic halo. Nature 365:623–625. https://doi.org/10.1038/365623a0
Beaulieu J-P, Bennett DP, Batista V et al (2016) Revisiting the microlensing event OGLE-2012-BLG-0026: a solar mass star with two cold giant planets. ApJ 824:83. https://doi.org/10.3847/0004-637x/824/2/83
Bennett DP, Rhie SH (2002) Simulation of a space-based survey for terrestrial extra-solar planets. ApJ 574:985–1003. https://doi.org/10.1086/340977
Bennett DP, Anderson J, Bond IA et al (2006) Identification of the OGLE-2003-BLG235/MOA-2003-BLG-53 planetary host star. ApJ 647:L171–L174. https://doi.org/10.1086/507585
Bird S, Cholis I, Munoz JB et al (2016) Did LIGO detect dark matter? PRL 116:201301. https://doi.org/10.1103/PhysRevLett.116.201301
Bond IA, Rattenbury NJ, Skuljan J et al (2002) Study by MOA of extrasolar planets by gravitational microlensing at high magnification. MNRAS 333:71–83. https://doi.org/10.1046/j.1365-8711.2002.05380.x
Bond IA, Udalski A, Jaroszynski M et al (2004) OGLE 2003-BLG-235/MOA 2003-BLG-52: a planetary microlensing event. ApJ 606:L155–L158. https://doi.org/10.1086/420928
Bond IA (2012) The first extrasolar planet detected via gravitational microlensing. New Astron Rev 56:25–32. https://doi.org/10.1016/j.newar.2011.06.004
Carr B, Kuhuel F, Sandstad M (2016) Primordial black holes as dark matter. PRD 94:083504. https://doi.org/10.1103/PhysRevD.94.083504
Cassan A, Kubas D, Beaulieu J-P et al (2012) One or more bound planets per milky way star from microlensing observations. Nature 481:167–169. https://doi.org/10.1038/nature10684
Freeman M, Philpott L, Abe F et al (2015) Can the masses of isolated planetary mass gravitational lenses be measured by terrestrial parallax? ApJ 799:181. https://doi.org/10.1088/0004-637X/799/2/181
Gould A (1992) Extending the MACHO search to about 106 solar masses. ApJ 392:442–451. https://doi.org/10.1086/171443
Gould A, Dong S, Gaudi BS et al (2010) Frequency of solar-like systems and of ice giants beyond the snow line from high magnification microlensing events in 2005–2008. ApJ 720:1073–1089. https://doi.org/10.1088/0004-637X/720/2/1073
Griest K, Safizadeh N (1998) The use of high-magnification microlensing events in detecting extrasolar planets. ApJ 500:37–50. https://doi.org/10.1086/305729
Han C, Kang YW (2003) Probing the spatial distribution of extrasolar planets with gravitational microlensing. ApJ 596:1320–1326. https://doi.org/10.1086/378191
Han C, Udalski A, Choi J-Y et al (2013) The second multiple planet system discovered by microlensing: OGLE-2012-BLG-0026Lb,c – a pair of Jovian mass planets beyond the snow line. ApJ 762:L28. https://doi.org/10.1088/2041–8205/762/2/L28
Hearnshaw JB, Abe F, Bond IA et al (2006) The MOA 1.8 metre alt-az wide-field survey telescope and the MOA project. In: Sutanyo W, Premadi P (eds) Proceedings of 9th Asian-Pacific IAU meeting July 2005, pp 272-273
Henderson CB, Gaudi BS, Han C et al (2014) Optimal survey strategies and predicted planet yields for the Korean microlensing telescope network. ApJ 794:52. https://doi.org/10.1088/0004-637X/794/1/52
Henderson CB, Poleski R, Penny M et al (2016) Campaign 9 of the K2 mission: observational parameters, scientific drivers and communal involvement for a simultaneous space- and ground-based microlensing survey. Publ Astron Soc Pac 128:124401. https://doi.org/10.1088/1538-3873/128/970/124401
Kobara S, Ohmori K, Wada K, Takeuchi M (2012) Three topics from the MOA collaboration. 16th international microlensing conference, Pasadena (unpublished)
Koshimoto N, Udalski A, Beaulieu J-P et al (2017) OGLE-2012-BLG-0950Lb: the first planet mass from only microlens parallax and lens flux. ApJ 153:1. https://doi.org/10.3847/1538-3881/153/1/1
Liebes S (1964) Gravitational lenses. PR 133:B835–B844. https://doi.org/10.1103/PhysRev.133.B835
Mao S, Paczynski B (1991) Gravitational microlensing by double stars and planetary systems. ApJ 374:L37–L40. https://doi.org/10.1086/186066
Muraki Y, Han C, Bennett DP et al (2011) Discovery and mass measurement of a cold, 10-earth mass planet and its host star. ApJ 741:22. https://doi.org/10.1088/0004-637X/741/1/22
Paczynski B (1986) Gravitational microlensing by the galactic halo. ApJ 304:1–5. https://doi.org/10.1086/164140
Paczynski B (1996) Gravitational microlensing in the local group. ARAA 34:419–460. https://doi.org/10.1146/annurev.astro.34.1.419
Philpott L (2012) Gravity’s optics and other worlds. Griffith Observer:76(6):2–18
Rattenbury NJ, Bond IA, Skuljan J, Yock PCM (2002) Planetary microlensing at high magnification. MNRAS 335:159–169. https://doi.org/10.1046/j.1365-8711.2002.05607.x
Rhie S, Bennett DP, Becker AC et al (2000) On planetary companions to the MACHO 98-BLG-35 microlens star. ApJ 533:378–391. https://doi.org/10.1086/308634
Sako T, Sekiguchi T, Sasaki M et al (2008) MOA-cam 3: a widefield mosaic CCD camera for a gravitational microlensing survey from new Zealand. Exp Astron 22:51–66. https://doi.org/10.1007/s10686-007-9082-5
Schneider P, Weiss A (1986) The two-point-mass lens – detailed investigation of a special asymmetric gravitational lens. A&A 164:237–259
Shvartzvald Y, Maoz D, Udalski A et al (2016) The frequency of snowline region planets from four years of OGLE-MOA-wise second generation microlensing. MNRAS 457:4089–4113. https://doi.org/10.1093/mnras/stw191
Spergel D, Gehrels N, Baltay C et al (2015) Wide-field InfrarRed survey telescope-astrophysics focused telescope assets WFIRST-AFTA 2015 report. ArXiv:1503.03757
Sumi T, Kamiya K, Udalski A et al (2011) Unbound or distant planetary mass population detected by gravitational Microlensing. Nature 473:349–352. https://doi.org/10.1038/nature10092
Sumi T, Udalski A, Bennett DP et al (2016) The first Neptune analog or super-earth with Neptune-like orbit: MOA-2013-BLG-605Lb. ApJ 825:112. https://doi.org/10.3847/0004-637X/825/2/112
Suzuki D, Bennett DP, Sumi T et al (2016) The exoplanet mass ratio function from the MOA-II survey: discovery of a break and likely peak at a Neptune-mass. ApJ 833:145. https://doi.org/10.3847/1538-4357/833/2/145
Udalski A, Szymanski M, Kaluzay J et al (1993) The optical gravitational microlensing experiment. Discovery of the first candidate microlensing event in the direction of the Galactic Bulge. Acta Astron 43:289–294
Yanagisawa T, Muraki Y, Matsubara Y et al (2000) Wide-field camera for gravitational microlensing survey: MOA-cam2. Exp Astron 10:519–535
Yock P (2012) A quarter century of astrophysics with Japan. NZ Sci Rev 69(3):61–70
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Yock, P., Muraki, Y. (2017). Microlensing Surveys for Exoplanet Research (MOA). In: Deeg, H., Belmonte, J. (eds) Handbook of Exoplanets . Springer, Cham. https://doi.org/10.1007/978-3-319-30648-3_122-1
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DOI: https://doi.org/10.1007/978-3-319-30648-3_122-1
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