학술논문
Two-Dimensional Eclipse Mapping of the Hot Jupiter WASP-43b with JWST MIRI/LRS
Document Type
Working Paper
Author
Hammond, Mark; Bell, Taylor J.; Challener, Ryan C.; Lewis, Neil T.; Mansfield, Megan Weiner; Malsky, Isaac; Rauscher, Emily; Bean, Jacob L.; Carone, Ludmila; Mendonça, João M.; Teinturier, Lucas; Tan, Xianyu; Crouzet, Nicolas; Kreidberg, Laura; Morello, Giuseppe; Parmentier, Vivien; Blecic, Jasmina; Désert, Jean-Michel; Helling, Christiane; Lagage, Pierre-Olivier; Molaverdikhani, Karan; Nixon, Matthew C.; Rackham, Benjamin V.; Yang, Jingxuan
Source
Subject
Language
Abstract
We present eclipse maps of the two-dimensional thermal emission from the dayside of the hot Jupiter WASP-43b, derived from an observation of a phase curve with the JWST MIRI/LRS instrument. The observed eclipse shapes deviate significantly from those expected for a planet emitting uniformly over its surface. We fit a map to this deviation, constructed from spherical harmonics up to order $\ell_{\rm max}=2$, alongside the planetary, orbital, stellar, and systematic parameters. This yields a map with a meridionally-averaged eastward hot-spot shift of $(7.75 \pm 0.36)^{\circ}$, with no significant degeneracy between the map and the additional parameters. We show the latitudinal and longitudinal contributions of the day-side emission structure to the eclipse shape, finding a latitudinal signal of $\sim$200 ppm and a longitudinal signal of $\sim$250 ppm. To investigate the sensitivity of the map to the method, we fix the non-mapping parameters and derive an "eigenmap" fitted with an optimised number of orthogonal phase curves, which yields a similar map to the $\ell_{\rm max}=2$ map. We also fit a map up to $\ell_{\rm max}=3$, which shows a smaller hot-spot shift, with a larger uncertainty. These maps are similar to those produced by atmospheric simulations. We conclude that there is a significant mapping signal which constrains the spherical harmonic components of our model up to $\ell_{\rm max}=2$. Alternative mapping models may derive different structures with smaller-scale features; we suggest that further observations of WASP-43b and other planets will drive the development of more robust methods and more accurate maps.
Comment: Accepted for publication in The Astronomical Journal
Comment: Accepted for publication in The Astronomical Journal