摘要
对Be／X射线双星LSI＋65°010／2S0114＋65连续四年（1992—1995年）的光学光谱观测发现，在1992年11月它的Ha发射线等值宽度在4天内从－0．43A增至－1．48A,增加了约3．5倍．此剧烈变化支持LSI＋65°10的光学子星是一颗Be星而非超巨星的论点．我们的观测还发现，1994年9月它的Ha发射线轮廓呈明显的双峰结构，但与普通Be星中由于旋转气壳而形成的双峰不同，其红峰处于Ha理论波长附近，紫峰却紫移了7．2A．我们认为此双峰可能产生在LSI＋65°010的不同HⅡ区中，即红峰产生于Be星周围的气壳内，而紫峰很可能产生于在轨道上快速运动的中子星周围的HⅡ区中，此观测可能提供了中子星周围存在HⅡ区的证据．同样，我们认为1992年11月4日观测到的Ha发射线红翼几乎不变，紫翼却大幅增加的现象也是由于中子星周围的HⅡ区造成的．
The optical spectroscopic observations of the Be/X-ray binary LSI + 65° 010 show a dramatic variability in 1992 and a only mild one during 1993-1995. A sudden increase of a factor larger than three in the equivalent width of Ha emission line profile within four days was present in November 1992. This supports the view point that the primary is a Be star rather than a supergiant. A well-defined double-peaked profile is seen in the spectrum in September 1994. The red peak is still at λ 6563, while the blue peak is at - 7.2A from the red one. We suggest that such a profile may be interpreted with the emission line from the shell of the Be star superposing on that from the HⅡ region around the neutron star. This provides the first direct obseravtional evidence for existence of a HⅡ region around the compact object caused by X-ray emission. It is interesting to note that the red side of the Ha line did not change on Nov.4, 1992, while the blue side looked greatly enhanced. This,we suggest, may also be caused by the HⅡ region around the neutron star.
出处
《天文学报》
CSCD
北大核心
1998年第2期212-216,共5页
Acta Astronomica Sinica
基金
中国科学院天文委员会资助
