Towards Robust Atmospheric Retrievals for Cloudy L Dwarfs: Tests on T Dwarf Spectra

Retrieving atmospheric properties from spectra is the only method through which properties of brown dwarf atmospheres can be determined since in situ measurements are impossible at astronomical distances. But to date, retrieval frameworks with clouds have not been robustly verified for accuracy despite the fact that clouds are abundant in cooling brown dwarfs. The overarching goal of my thesis work is to incorporate the more complex physics governing cloud formation into retrieval frameworks for cloudy L dwarf atmospheres and later for cloudy planetary atmospheres. Before this goal can be accomplished, we must first test a number of assumptions regarding thermal structure, chemical equilibrium, and uniform chemical abundances on the more straightforward and relatively cloud-free T dwarf emission spectra. Preliminary results for the benchmark T dwarf Gl 570D are presented.