Rotational broadening and Doppler tomography of the quiescent X-ray nova Centaurus X-4
Rotational broadening and Doppler tomography of the quiescent X-ray nova Centaurus X-4
复制标题
静态 X 射线新星 Centaurus X-4 的旋转展宽和多普勒断层扫描
DOI：
10.1046/j.1365-8711.2002.05521.x
复制
发表时间：
2002
影响因子：
4.8
通讯作者：
UK.
中科院分区：
文献类型：
--
作者：
M. Torres;J. Casares;I. G. Martínez;P. Laguna;S. Iac;Spain Univ. College;Cork;Ireland Department of Astrophysics;Oxford;U. Southampton;UK.
我们提出了高和中等分辨率光谱的X射线新星半人马座X-4在其静止阶段。我们对吸收特征的分析支持伴星星星的K3-K5 V光谱分类，它贡献了Hα总通量的75%。利用高分辨光谱，我们测量了次级星星的转动展宽为vsin i=43±6 km s-1，并确定了双星质量比q=0.17±0.06。结合我们对K2和q的结果以及已发表的双星倾角极限，我们将致密天体和次级星星的质量限制在0.49<M1<2.49 M和0.04<M2<0.58 M的范围内。Hα线的多普勒图像显示了来自次级星星的辐射，但没有热点存在。我们讨论了这种排放的可能来源。
We present high- and intermediate-resolution spectroscopy of the X-ray nova Centaurus X-4 during its quiescent phase. Our analysis of the absorption features supports a K3–K5 V spectral classification for the companion star, which contributes ≃75 per cent of the total flux at Hα. Using the high-resolution spectra we have measured the rotational broadening of the secondary star to be v sin i=43±6 km s-1 and determined a binary mass ratio of q=0.17±0.06. Combining our results for K2 and q with the published limits for the binary inclination, we constrain the mass of the compact object and the secondary star to the ranges 0.49<M1<2.49 M⊙ and 0.04<M2<0.58 M⊙. A Doppler image of the Hα line shows emission coming from the secondary star, but no hotspot is present. We discuss the possible origins of this emission.