Year: 2023
Type: article
Abstract: ABSTRACT In this paper, we compare the chemistry and the emission spectra of nitrogen-dominated cool, warm, and hot ultra-short-period (USP) super-Earth atmospheres in and out of chemical equilibrium at various surface pressure scenarios ranging from 10−1 to 10 bar. We link the one-dimensional vulcan chemical kinetic code, in which thermochemical kinetic and vertical transport and photochemistry are taken into account, to the one-dimensional radiative transfer model, petitradtrans, to predict the emission spectra of these planets. The radiative–convective temperature–pressure profiles were computed with the helios code. Then, using pandexo noise simulator, we explore the observability of the differences produced by disequilibrium processes with the JWST. Our grids show how different surface pressures can significantly affect the temperature profiles, the atmospheric abundances, and consequently the emission spectra of these planets. We find that the divergences due to disequilibrium processes would be possible to observe in cooler planets by targeting HCN, C2H4, and CO, and in warmer planets by targeting CH4 with HCN, using the NIRSpec and MIRI LRS JWST instruments. These species are also found to be sensitive indicators of the existence of surfaces on nitrogen-dominated USP super-Earths, providing information regarding the thickness of these atmospheres.
Institutions: Cadi Ayyad University, Johns Hopkins University, University of Washington, Johns Hopkins University Applied Physics Laboratory, Center for Astrophysics Harvard & Smithsonian, Universidade do Porto, Institute of Astrophysics and Space Sciences, Centro de Astrofísica da Universidade do Porto
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4362703733