A Systematic Study of Departures from Chemical Equilibrium in the Atmospheres of Substellar Mass Objects

Understand

We present a systematic study of the spectral consequences of departures from chemical equilibrium in the atmospheres of L and T dwarfs, and for even cooler dwarfs.

• The temperature/pressure profiles of the non-equilibrium models are fully consistent with the non-equilibrium chemistry.
• Our grid of non-equilibrium models includes spectra for effective temperatures from 200 K to 1800 K, three surface gravities, four possible values of the coefficient of eddy diffusion in the radiative zone, and three different CO/CH$_4$ chemical reaction prescriptions.
• We find that the non-equilibrium overabundance of CO translates into flux suppressions in the M ($\sim4-$5 $\mu$m) band of at most $\sim$40% between effective temperatures of 600 and 1800 K.