Optically-Thick Stellar Winds and Photospheres of Hot Stars

研究人员将继续对质量损失的恒星大气进行理论建模。重点放在非常明亮和大质量的恒星上，通常超过40个太阳质量。为了获得有效温度，需要精确的线谱。对光谱的如此详细的理解不仅提供了关于风的原因的信息，还提供了关于恒星演化的性质的信息，例如对流；识别遥远星系中此类恒星的光度的方法；以及对星际介质的影响。最热的可观测恒星为我们对恒星演化的理解提供了重要的考验，它们为星际介质提供了能量；它们可能成为遥远星系距离的准确指示器。然而，只有在建立了热星大气的详细模型后，才能可靠地解释对热星的观测。该模型必须包括关于离开恒星的风的速度以及风中吸收和重新发射恒星辐射的原子的信息。这样的计算直到最近才成为可能。调查人员站在这项研究的最前线。这笔赠款将允许他们对恒星大气进行建模，以便最热恒星的光谱确实可以成为天文研究的有效工具。

The investigators will continue theoretical modeling of stellar atmospheres with mass loss. The emphasis rests on very luminous and massive stars, typically over 40 solar masses. Accurate line spectra are needed to obtain effective temperatures. Such detailed understanding of the spectra yields information not only about the causes of the winds but also about properties of stellar evolution, such as convection; ways to identify the luminosities of such stars in distant galaxies; and the effects on the interstellar medium. The hottest observable stars provide important tests of our understanding of stellar evolution, they energize the interstellar medium; and they may become accurate indicators of distances of distant galaxies. However, observations of hot stars can be interpreted reliably only after a detailed model of their atmospheres has been constructed. The model must include information on both the velocities of the winds leaving the stars and on the atoms in the winds that absorb and re-emit the stellar radiation. Such a computation has only recently become possible. The investigators are at the forefront of this research. This grant will allow them to model the stellar atmospheres so that the spectra of the hottest stars can indeed become effective tools for astronomical research.