标题： 双极喷流和 supersoft X 射线源 RX J0019.8+2156 的轨道动力学 显示英文标题

标题： Bipolar Jets and Orbital Dynamics of the Supersoft X-Ray Source RX J0019.8+2156

摘要： 1994年至1997年，我们监测了RXJ0019.8+2156的光学光谱。 这个超软X射线源是银河系中仅有的两个被认为由于从双星伴星高转移率导致表面燃烧氢的吸积白矮星之一。 精确的轨道历元是从HeII发射线的径向速度测量值推导出来的，这些发射线表现出稳定的半振幅速度71.2±3.6 km/s。 我们报告了瞬变低速双极喷流的发现。 这些喷流由红移和蓝移的发射线对表示，流出速度为v cos(i) = 815 km/s，其中i是双星倾角。 当存在时，喷流线也表现出71 km/s的轨道调制，这表明喷流几乎与轨道面垂直。 在大多数情况下，H线轮廓进一步被P Cygni吸收改变。 我们展示了喷流和P Cygni特征具有非常不同的时间特性和双星相位依赖性。 因此，喷流物质和吸收风必须占据非常不同的几何结构。 最后，测量的质量函数与双星演化模型结合，建议一个限制，i < 40度。 为了解释高转移率的一个特定模型需要16 < i < 25。 然而，在如此小的倾角下，很难解释轨道光曲线的大振幅。 相比之下，简单模型拟合喷流流出线表明轨道倾角角度为35 < i < 60。 显示英文摘要

摘要： From 1994 to 1997 we monitored the optical spectrum of RXJ0019.8+2156. This supersoft X-ray source is one of only two accreting white dwarfs in the Galaxy thought to be burning hydrogen on their surface as a consequence of a high rate of mass transfer from a binary companion. Accurate orbital ephemerides are derived from radial velocity measure- ments of HeII emission lines, which exhibit a stable velocity semi- amplitude of 71.2 +- 3.6 km/s. We report the discovery of transient, low-velocity, bipolar jets. These jets are respresented by redshifted and blueshifted pairs of emission lines with an outflow velocity of v cos(i) = 815 km/s, where i is the binary inclination angle. When present, the jet lines also exhibit an orbital modulation of 71 km/s, which indicates that the jets are oriented nearly perpendicular to the orbital plane. On most occasions, the Hline profiles are further altered by P Cygni absorption. We show that the jets and the P Cygni features have very different temporal characteristics and binary phase dependence. The jet material and the absorbing wind must therefore occupy very different geometries. Finally, the measured mass function is combined with binary evolution models to suggest a limit, i < 40 deg. A particular model invoked to explain a high rate of mass transfer requires 16 < i < 25. However, at such small inclination it is difficult to explain the large amplitude of the orbital light curve. By contrast, a simple model fit to the jet outflow lines indicates an orbital inclination angle of 35 < i < 60.