A Model of the H$\alpha$ and Na Transmission Spectrum of HD 189733b

摘要: This paper presents a detailed hydrostatic model of the upper atmosphere HD 189733b, with goal constraining its temperature, particle densities, and radiation field over pressure range $10^{-4}-10\, \mu \rm bar$, where observed H$\alpha$ transmission spectrum is produced. The atomic hydrogen level population computed including both collisional radiative transition rates. Ly$\alpha$ resonant scattering using Monte-Carlo simulation. spectra are in broad agreement data. Excitation H(2$\ell$) mainly by excitation due to large intensity. density nearly flat two decades pressure, optically thick H$\alpha$. Additional models for stellar Lyman continuum (LyC) flux suggest that variability transit depth may be LyC. Since metal lines provide dominant cooling this part atmosphere, structure sensitive species such as Mg Na which themselves constrained observations. D have comparable absorption depths, we argue center also formed layer line formed.