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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 | 2006/10 |
| 形態種別 | その他 |
| 標題 | Imprint of gravitational lensing by Population III stars in gamma-ray burst light curves |
| 執筆形態 | その他 |
| 掲載誌名 | ASTROPHYSICAL JOURNAL |
| 出版社・発行元 | UNIV CHICAGO PRESS |
| 巻・号・頁 | 650(1),pp.252-260 |
| 著者・共著者 | Y. Hirose,M. Umemura,A. Yonehara,J. Sato |
| 概要 | We propose a novel method of extracting the imprint of gravitational lensing by Population III stars in the light curves of gamma-ray bursts ( GRBs). Significant portions of GRBs can originate in hypernovae of Population III stars and be gravitationally lensed by foreground Population III stars or their remnants. If the lens mass is on the order of 10(2) - 10(3) M-circle dot and the lens redshift is greater than 10, the time delay between two lensed images of a GRB is approximate to 1 s and the image separation is approximate to 10 mu as. Although it is difficult to resolve the two lensed images spatially with current facilities, the light curves of the two images are superimposed with a delay of approximate to 1 s. GRB light curves usually exhibit noticeable variability, where each spike is less than 1 s. If a GRB is lensed, all spikes are superimposed with the same time delay. Hence, if the autocorrelation of the light curve with changing time interval is calculated, it should show resonance at the time delay of the lensed images. Applying this autocorrelation method to GRB light curves that are archived as the BATSE catalog, we demonstrate that more than half of the light curves show recognizable resonance they are lensed. Furthermore, in 1821 GRBs we actually find one candidate for a GRB lensed by a Population III star, which may be located at redshift 20 - 200. The present method is quite straightforward and therefore provides an effective tool for searching for Population III stars at redshift greater than 10. Using this method, we may find more candidates for GRBs lensed by Population III stars in the data of the Swift satellite. |
| DOI | 10.1086/506169 |
| ISSN | 0004-637X |