Inhomogeneous Stellar Atmospheres

托马斯·艾尔斯的《非均匀恒星大气》AST-9987414。Ayres正在使用一氧化碳(CO)的观测和理论数据来研究太阳型恒星的大气层。在高温(T~7000K)的太阳大气中，相对较冷的(T~3500K)CO分子在高海拔地区的存在一直是太阳物理学中的一个难题，因为在这个地区应该只存在热的色球气体，而分子是相当意想不到的。在太阳中，CO位于分离光球动力学控制的等离子体和日冕的磁控气体的过渡区的中间。预计这一区域将为太阳活动水平提供重要的诊断线索，并间接为太阳活动周期中的日地相互作用提供线索。艾尔斯博士正在将这项研究扩展到其他太阳类型的恒星，方法是在5微米的红外区进行观测，在那里可以探测到CO转变，以探测这一磁性转变区的冷端。这是对探测更热区域的可见光和紫外光观测的补充。这项工作的主要目标是：(1)利用CO观测来调查太阳活动区；(2)调查太阳边缘的低色球结构；(3)测量太阳类型恒星的CO光谱；(4)建立包含动态CO形成和破坏过程的太阳和恒星大气的二维静态模型。

Ayres, Thomas"Inhomogeneous Stellar Atmospheres"AST-9987414Dr. Ayres is investigating the atmospheres of solar-type stars using observational and theoretical data for carbon monoxide (CO). The presence of relatively cool (T~3500K) CO molecules at high altitudes in the hot (T~7000K) solar atmosphere is a long-standing puzzle in solar physics, since in this region only hot chromospheric gas should exist and molecules are quite unexpected. In the Sun CO is found in the middle of the transition region that separates the kinetically controlled plasma of the photosphere and the magnetically controlled gas of the corona. This region is expected to provide important diagnostic clues to Solar activity levels and, indirectly, to the Sun-Earth interactions during the solar activity cycle. Dr. Ayres is extending this research to other solar-type stars using observations at the 5 micron infrared region where CO transitions are detectable to probe the cool side of this magnetic transition zone. This complements the visible and ultraviolet observations that probe the hotter regime. The primary objectives of this work are to: (1) use CO observations to investigate solar active regions; (2) investigate the low chromospheric structure at the solar limb; (3) survey the CO spectra of solar type stars; and (4) construct two-dimensional static models of the solar and stellar atmospheres that incorporate dynamic CO formation and destruction processes.Funding for this project was provided by the NSF program for Stellar Astronomy & Astrophysics (AST/SAA).