Abstract

We have performed a detailed analysis of the atmospheric properties of two late-T type brown dwarfs, 2MASSI J0415195-093506 and 2MASS J05591914-140448. For each brown dwarfs, we combined the spectra of each brown dwarf from the ground at 1-2.5 µm, AKARI at 2.5-5 µm, and from the Spitzer Space Telescope at 5-15 µm. For this project, we are particularly interested in probing the extent of vertical mixing. For this analysis, we used the Planetary Intensity Code for Atmospheric Scattering (PICASO), which is a code that creates a radiative transfer model for a given set of atmospheric parameters. With PICASO we find that metallicity has little effect on model fits, especially as it concerns modeling disequilibrium chemistry features. Vertical mixing and C/O, along with temperature, are parameters that play a significant role in creating accurate model fits to spectra. The best-fit PICASO models for the spectra of 2MASS 0415 and 2MASS 0559 struggle to accurately model the CO2 absorption feature, which indicates that there is a need to improve understanding on what drives the observed CO2 abundance.

Degree

MS

College and Department

Physics and Astronomy; Computational, Mathematical, and Physical Sciences

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2026-04-22

Document Type

Thesis

Keywords

brown dwarf, Spitzer, AKARI, atmospheric modeling, infrared spectroscopy, low-mass stars

Language

english

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