Spectroscopic Imaging of Evolved Star Envelopes

最近的毫米波射电的构造，使得在恒星演化的高级阶段，以各种分子线的形式，对恒星的流出物进行成像成为可能。这一成就使这些流出物的运动学得以研究，从而了解非球形行星状星云是如何形成的，以及气体和尘埃粒子之间的化学相互作用作为距离的函数。首席研究员（PI）将使用位于加州哈特克里克的“BIMA”射电阵列和位于格雷厄姆山上的新亚利桑那-德国毫米波望远镜来研究这些问题。这些研究有望使人们更好地理解为什么这些恒星周围大约一半的行星状星云明显是非球形的，并使人们更好地理解星际颗粒的化学性质。后一个问题对于星际气体的热力学条件，并最终对新一代恒星的凝结是重要的。//

The recent construction of radio millimeter wavelengths has permitted the imaging of outflows from stars in advanced stages of stellar evolution in lines of various molecules. This accomplishment permits the kinematics of these outflows to be studied, leading to an understanding of how nonspherical planetary nebulae form, as well as the chemical interactions between gas and dust particles as a function of distance. The Principal Investigator (PI) will use the "BIMA" radio array at Hat Creek, California and the new Arizona-German millimeter-wave telescope on Mt. Graham to study these questions. These studies are expected to lead to a better understanding of why about one half the planetary nebulae around these stars are significantly nonspherical and to lead to a better understanding of the chemistry of interstellar grains. The latter question is of importance to the thermodynamic conditions of interstellar gas and ultimately to the condensation of new generations of stars.//