标题： 银河系逃逸OB星弓形激波的可观测性 显示英文标题

标题： On the observability of bow shocks of Galactic runaway OB stars

摘要： 被从其母星团中弹射出来并在星际介质（ISM）中以超音速航行的大质量恒星被归类为流亡恒星。 它们会产生围绕恒星的弓形激波星云，这些星云是可以观测到的。 我们展示了对银河系OB型恒星在密度范围从n_ISM=0.01到10.0/cm3的环境中的代表性恒星风弓形激波的二维轴对称流体动力学模拟。 无论它们在银河系中的位置如何，我们确认红外波段是搜索大质量恒星弓形激波最合适的波段。 它们的光谱能量分布是分析它们的合适工具，因为它们的辐射不依赖于可能影响不稳定、薄壳状弓形激波的临时效应。 我们对由高质(~40 Mo)逃逸恒星产生的银河系弓形激波的数值模型得出H$\alpha$通量，这些通量可以通过SuperCOSMOS H-Alpha Survey等设施进行观测。 最明亮的弓形激波星云是在星际介质密度较高的区域产生的。 我们预测，通过Rayleigh敏感设施在Ha波段观测到的弓形激波是由初始质量大于约20 Mo的恒星形成的。 我们对OB型恒星弓形激波的模型显示，在波长范围3 <= lambda <= 50微米内有发射峰值，这可能比逃逸恒星本身亮几个数量级，尤其是对于初始质量大于20 Mo的恒星。 显示英文摘要

摘要： Massive stars that have been ejected from their parent cluster and supersonically sailing away through the interstellar medium (ISM) are classified as exiled. They generate circumstellar bow shock nebulae that can be observed. We present two-dimensional, axisymmetric hydrodynamical simulations of a representative sample of stellar wind bow shocks from Galactic OB stars in an ambient medium of densities ranging from n_ISM=0.01 up to 10.0/cm3. Independently of their location in the Galaxy, we confirm that the infrared is the most appropriated waveband to search for bow shocks from massive stars. Their spectral energy distribution is the convenient tool to analyze them since their emission does not depend on the temporary effects which could affect unstable, thin-shelled bow shocks. Our numerical models of Galactic bow shocks generated by high-mass (~40 Mo) runaway stars yield H$\alpha$ fluxes which could be observed by facilities such as the SuperCOSMOS H-Alpha Survey. The brightest bow shock nebulae are produced in the denser regions of the ISM. We predict that bow shocks in the field observed at Ha by means of Rayleigh-sensitive facilities are formed around stars of initial mass larger than about 20 Mo. Our models of bow shocks from OB stars have the emission maximum in the wavelength range 3 <= lambda <= 50 micrometer which can be up to several orders of magnitude brighter than the runaway stars themselves, particularly for stars of initial mass larger than 20 Mo.