标题： 一个来自天鹅座X-3的单侧高相对论性喷流 显示英文标题

标题： A One-sided, Highly Relativistic Jet from Cygnus X-3

摘要： 非常长基线阵列对X射线双星天鹅座X-3的图像在1997年2月4日10 Jy爆发峰值后的2、4和7天获得。 前两张图像显示一条弯曲的一侧喷流，第三张显示一个散射扩展的盘，可能位于核心的位置。 喷流的弯曲度从第一个时期到第二个时期发生了变化，这强烈表明喷流存在进动。 接近喷流的通量密度与（未被检测到的）远离喷流的通量密度之比大于330；如果这种不对称性是由于多普勒增强引起的，则喷流速度大于0.81c。 进动喷流模型拟合，结合喷流本身本质上对称且是在主要爆发期间或之后喷射的假设，得出以下限制条件：喷流相对于视线的倾角必须小于14度；圆锥张角必须小于12度；进动周期必须大于60天。 显示英文摘要

摘要： Very Long Baseline Array images of the X-ray binary, Cygnus X-3, were obtained 2, 4 and 7 days after the peak of a 10 Jy flare on 4 February 1997. The first two images show a curved one-sided jet, the third a scatter-broadened disc, presumably at the position of the core. The jet curvature changes from the first to the second epoch, which strongly suggests a precessing jet. The ratio of the flux density in the approaching to that in the (undetected) receding jet is > 330; if this asymmetry is due to Doppler boosting, the implied jet speed is > 0.81c. Precessing jet model fits, together with the assumptions that the jet is intrinsically symmetric and was ejected during or after the major flare, yield the following constraints: the jet inclination to the line of sight must be < 14 degrees; the cone opening angle must be < 12 degrees; and the precession period must be > 60 days.