Can I read Effectively Calculating Gaseous Absorption in Radiative Transfer Models of Exoplanetary and Brown Dwarf Atmospheres on EtoBox?

Effectively Calculating Gaseous Absorption in Radiative Transfer Models of Exoplanetary and Brown Dwarf Atmospheres by Garland, R.; Irwin, P. G. J. is a scholarly article available to read on EtoBox.

What is Effectively Calculating Gaseous Absorption in Radiative Transfer Models of Exoplanetary and Brown Dwarf Atmospheres about?

Sophisticated atmospheric retrieval algorithms, such as Nested Sampling, explore large parameter spaces by iterating over millions of radiative transfer (RT) calculations. Probability distribution functions for retrieved parameters are highly sensitive to assumptions made within the RT forward model. One key difference between RT models is the computation of the gaseous absorption throughout the atmosphere. We compare two methods of calculating gaseous absorption, cross-sections and correlated-$k$, by examining their resulting spectra of a number of typical \ce{H2}-He dominated exoplanetary and brown dwarf atmospheres. We also consider the effects of including \ce{H2}-He pressure-broadening in some of these examples. We use NEMESIS to compute forward models. Our $k$-tables are verified by comparison to ExoMol cross-sections provided online and a line-by-line calculation. For test cases with typical resolutions ($\Delta \nu = 1$cm$^{-1}$), we show that the cross-section method overestimates the amount of absorption present in the atmosphere and should be used with caution. For mixed-gas atmospheres the morphology of the spectra changes, producing `ghost' features. The two methods pr

Author

Garland, R.; Irwin, P. G. J.

Published

2019

Language

EN