Detecting first-star Ly alpha spheres through gravitational telescopes
文献类型：期刊论文
| 作者 | Li, Guoliang; Zhang, Pengjie; Chen, Xuelei |
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2007-09-01 |
| 卷号 | 666期号:1页码:45-50 |
| 关键词 | early universe gravitational lensing |
| 英文摘要 | Ly alpha spheres, that is, regions around the first stars that are illuminated by Ly alpha photons and exhibit a 21 cm absorption feature against the cosmic microwave background, are smoking guns at the dawn of the reionization epoch. Although an overwhelming radio foreground makes their detection extremely difficult, we point out that strong gravitational lensing can significantly improve the feasibility of observing these objects. Since Ly alpha spheres have similar to 10'' sizes, comparable to the size of galaxy-cluster caustics, the individual images of a strongly lensed Ly alpha sphere will often merge together and form an irregularly shaped single structure in the 21 cm sky. Using high- resolution N-body Lambda CDM simulations, we find that the lensing probability to have a magnification greater than 10 is similar to 10(-5). This results in greater than or similar to 10(6) strongly lensed Ly alpha spheres across the sky, which should be the primary targets for first detections of Ly alpha spheres. Although the required total radio-array collecting area for their detection is large (similar to 100 km(2)), a design composed of long fixed cylindrical reflectors can significantly reduce the total cost of such a radio telescope to the level of the Square Kilometre Array and make the detection of these very first objects feasible. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | GALAXY CLUSTERS ; GIANT ARCS ; GAS ; SHAPES ; HALOS |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000249058600004 |
| 源URL | [http://119.78.226.72/handle/331011/19428]  |
| 专题 | 上海天文台_星系宇宙学重点实验室 |
| 作者单位 | 1.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 2.Shanghai Astron Observ, Joint Inst Galaxy & Cosmol JOINGC, Beijing 100012, Peoples R China 3.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China |
| 推荐引用方式 GB/T 7714 | Li, Guoliang,Zhang, Pengjie,Chen, Xuelei. Detecting first-star Ly alpha spheres through gravitational telescopes[J]. ASTROPHYSICAL JOURNAL,2007,666(1):45-50. |
| APA | Li, Guoliang,Zhang, Pengjie,&Chen, Xuelei.(2007).Detecting first-star Ly alpha spheres through gravitational telescopes.ASTROPHYSICAL JOURNAL,666(1),45-50. |
| MLA | Li, Guoliang,et al."Detecting first-star Ly alpha spheres through gravitational telescopes".ASTROPHYSICAL JOURNAL 666.1(2007):45-50. |
入库方式： OAI收割
来源：上海天文台
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