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ヨネハラ アツノリ
YONEHARA ATSUNORI
米原 厚憲 所属 京都産業大学 理学部 宇宙物理・気象学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2016/04 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | The frequency of snowline-region planets from four-years of OGLE-MOA-Wise second-generation microlensing |
| 執筆形態 | その他 |
| 掲載誌名 | Monthly Notices of the Royal Astronomical Society |
| 巻・号・頁 | 457(4),pp.4089-4113 |
| 著者・共著者 | Y. Shvartzvald,D. Maoz,A. Udalski,T. Sumi,M. Friedmann,S. Kaspi,R. Poleski,M. K. Szymański,J. Skowron,S. Kozłowski,Ł. Wyrzykowski,P. Mróz,P. Pietrukowicz,G. Pietrzyński,I. Soszyński,K. Ulaczyk,F. Abe,R. K. Barry,D. P. Bennett,A. Bhattacharya,I. A. Bond,M. Freeman,K. Inayama,Y. Itow,N. Koshimoto,C. H. Ling,K. Masuda,A. Fukui,Y. Matsubara,Y. Muraki,K. Ohnishi,N. J. Rattenbury,To. Saito,D. J. Sullivan,D. Suzuki,P. J. Tristram,Y. Wakiyama,A. Yonehara |
| 概要 | We present a statistical analysis of the first four seasons from a<br />
"second-generation" microlensing survey for extrasolar planets, consisting of<br /> near-continuous time coverage of 8 deg$^2$ of the Galactic bulge by the OGLE,<br /> MOA, and Wise microlensing surveys. During this period, 224 microlensing events<br /> were observed by all three groups. Over 12% of the events showed a deviation<br /> from single-lens microlensing, and for $\sim$1/3 of those the anomaly is likely<br /> caused by a planetary companion. For each of the 224 events we have performed<br /> numerical ray-tracing simulations to calculate the detection efficiency of<br /> possible companions as a function of companion-to-host mass ratio and<br /> separation. Accounting for the detection efficiency, we find that<br /> $55^{+34}_{-22}\%$ of microlensed stars host a snowline planet. Moreover, we<br /> find that Neptunes-mass planets are $\sim10$ times more common than<br /> Jupiter-mass planets. The companion-to-host mass ratio distribution shows a<br /> deficit at $q\sim10^{-2}$, separating the distribution into two companion<br /> populations, analogous to the stellar-companion and planet populations, seen in<br /> radial-velocity surveys around solar-like stars. Our survey, however, which<br /> probes mainly lower-mass stars, suggests a minimum in the distribution in the<br /> super-Jupiter mass range, and a relatively high occurrence of brown-dwarf<br /> companions. |
| DOI | 10.1093/mnras/stw191 |
| arXiv ID | arXiv:1510.04297 |
| PermalinkURL | http://arxiv.org/abs/1510.04297v2 |