标题： 非热射电辐射来自碰撞风双星 显示英文标题

标题： Non-Thermal Radio Emission from Colliding-Wind Binaries

摘要： 在碰撞风双星中，激波将一部分电子加速到相对论速度。 这些电子随后在射电波长发射同步辐射。 我们是否能探测到这种辐射取决于双星组件的恒星风中自由-自由吸收区域的大小。 人们预期长周期双星是可以探测到的，但短周期双星则不能。 因此，发现Cyg OB2 No. 8A（P = 21.9 d）的变异性与轨道相位锁定显得令人惊讶。 为了研究这一点，我们开发了一个相对论电子生成模型（包括冷却和对流）以及同步辐射通过恒星风的辐射转移。 使用这个模型，我们表明Cyg OB2 No. 8A的同步辐射发射区域足以延伸到自由-自由吸收区域之外，从而在射电流量中产生轨道锁定的变异性。 该模型也可以应用于其他非热发射体，并将在解释未来调查（如COBRaS - Cyg OB2射电调查）的观测结果方面有所帮助。 显示英文摘要

摘要： In colliding-wind binaries, shocks accelerate a fraction of the electrons up to relativistic speeds. These electrons then emit synchrotron radiation at radio wavelengths. Whether or not we detect this radiation depends on the size of the free-free absorption region in the stellar winds of both components. One expects long-period binaries to be detectable, but not the short-period ones. It was therefore surprising to find that Cyg OB2 No. 8A (P = 21.9 d) does show variability locked with orbital phase. To investigate this, we developed a model for the relativistic electron generation (including cooling and advection) and the radiative transfer of the synchrotron emission through the stellar wind. Using this model, we show that the synchrotron emitting region in Cyg OB2 No. 8A does extend far enough beyond the free-free absorption region to generate orbit-locked variability in the radio flux. This model can also be applied to other non-thermal emitters and will prove useful in interpreting observations from future surveys, such as COBRaS - the Cyg OB2 Radio Survey.