DISCOVERY OF A 693.5 s PERIOD IN THE X-RAY BINARY 4U 1820-30: A SUPERHUMP INTERPRETATION
文献类型：期刊论文
| 作者 | Wang, Zhongxiang1 ; Chakrabarty, Deepto2,3
|
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2010-03-20 |
| 卷号 | 712期号:1页码:653-657 |
| 关键词 | binaries: close stars: individual (4U 1820-30) stars: low-mass stars: neutron X-rays: binaries |
| 英文摘要 | The X-ray source 4U 1820-30 in the globular cluster NGC 6624 is known as the most compact binary among the identified X-ray binaries (XRBs). Having an orbital period of 685.0 s, the source consists of a neutron star (NS) primary and likely a 0.06-0.08 M(circle dot) white dwarf (WD) secondary. Here, we report on far-ultraviolet (FUV) observations of this XRB, made with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. From our Fourier spectral analysis of the FUV timing data, we obtain a period of 693.5 +/- 1.3 s, which is significantly different from the orbital period. The light curve folded at this period can be described by a sinusoid, with a fractional semiamplitude of 6.3% and the phase zero (maximum of the sinusoid) at MJD 50886.015384 +/- 0.000043 (TDB). While the discovered FUV period may be consistent with a hierarchical triple system model that was previously considered for 4U 1820-30, we suggest that it could instead be the indication of superhump modulation, which arises from an eccentric accretion disk in the binary. The X-ray and FUV periods would be the orbital and superhump periods, respectively, indicating a 1% superhump excess and a WD/NS mass ratio around 0.06. Considering 4U 1820-30 as a superhump source, we discuss the implications. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | AM-CANUM-VENATICORUM ; NGC 6624 ; CATACLYSMIC BINARIES ; ORBITAL PERIOD ; VW HYDRI ; 4U-1820-30 ; MASS ; ULTRAVIOLET ; MODULATION ; VARIABLES |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000275222900057 |
| 源URL | [http://119.78.226.72/handle/331011/26314]  |
| 专题 | 上海天文台_星系宇宙学重点实验室 |
| 作者单位 | 1.Shanghai Astron Observ, Shanghai 200030, Peoples R China 2.MIT, Dept Phys, Cambridge, MA 02139 USA 3.MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA |
| 推荐引用方式 GB/T 7714 | Wang, Zhongxiang,Chakrabarty, Deepto. DISCOVERY OF A 693.5 s PERIOD IN THE X-RAY BINARY 4U 1820-30: A SUPERHUMP INTERPRETATION[J]. ASTROPHYSICAL JOURNAL,2010,712(1):653-657. |
| APA | Wang, Zhongxiang,&Chakrabarty, Deepto.(2010).DISCOVERY OF A 693.5 s PERIOD IN THE X-RAY BINARY 4U 1820-30: A SUPERHUMP INTERPRETATION.ASTROPHYSICAL JOURNAL,712(1),653-657. |
| MLA | Wang, Zhongxiang,et al."DISCOVERY OF A 693.5 s PERIOD IN THE X-RAY BINARY 4U 1820-30: A SUPERHUMP INTERPRETATION".ASTROPHYSICAL JOURNAL 712.1(2010):653-657. |
入库方式： OAI收割
来源：上海天文台
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。