The Library
Carbon monoxide emission lines reveal an inverted atmosphere in the ultra hot Jupiter WASP-33 b consistent with an eastward hot spot
Tools
van Sluijs, Lennart, Birkby, Jayne L., Lothringer, Joshua, Lee, Elspeth K. H., Crossfield, Ian J. M., Parmentier, Vivien, Brogi, Matteo, Kulesa, Craig, McCarthy, Don and Charbonneau, David (2023) Carbon monoxide emission lines reveal an inverted atmosphere in the ultra hot Jupiter WASP-33 b consistent with an eastward hot spot. Monthly Notices of the Royal Astronomical Society, 522 (2). pp. 2145-2170. doi:10.1093/mnras/stad1103 ISSN 1365-2966.
|
PDF
stad1103 (1).pdf - Published Version - Requires a PDF viewer. Available under License Creative Commons Attribution 4.0. Download (13Mb) | Preview |
Official URL: https://doi.org/10.1093/mnras/stad1103
Abstract
We report the first detection of CO emission at high spectral resolution in the day-side infrared thermal spectrum of an exoplanet. These emission lines, found in the atmosphere of the transiting ultra hot Jupiter (UHJ) WASP-33 b, provide unambiguous evidence of its thermal inversion. Using spectra from the MMT Exoplanet Atmosphere Survey (MEASURE, R ∼ 15 000), covering pre- and post-eclipse phases, we cross-correlate with 1D PHOENIX spectral templates to detect CO at S/N = 7.9 ($v_{\rm {sys}}=0.15^{+0.64}_{-0.65}$ km s−1, $K_{\rm {p}}=229.5^{+1.1}_{-1.0}$ km s−1). Moreover, using cross-correlation-to-log-likelihood mapping, we find that the scaling parameter which controls the spectral line contrast changes with phase. We thus use the general circulation model SPARC/MITgcm post-processed by the 3D gCMCRT radiative transfer code to interpret this variation, finding it consistent with an eastward-shifted hot spot. Pre-eclipse, when the hot spot faces Earth, the thermal profiles are shallower leading to smaller line contrast despite greater overall flux. Post-eclipse, the western part of the day-side faces Earth and has much steeper thermal profiles, leading to larger line contrast despite less overall flux. This demonstrates that within the log-likelihood framework, even relatively moderate resolution spectra can be used to understand the 3D nature of close-in exoplanets, and that resolution can be traded for photon-collecting power when the induced Doppler-shift is sufficiently large. We highlight CO as a good probe of UHJ thermal structure and dynamics that does not suffer from stellar activity, unlike species that are also present in the host star e.g. iron lines.
Item Type: | Journal Article | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Subjects: | Q Science > QB Astronomy | |||||||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Physics | |||||||||
SWORD Depositor: | Library Publications Router | |||||||||
Library of Congress Subject Headings (LCSH): | Astronomical spectroscopy, Extrasolar planets -- Atmospheres, Extrasolar planets -- Measurement | |||||||||
Journal or Publication Title: | Monthly Notices of the Royal Astronomical Society | |||||||||
Publisher: | Oxford University Press (OUP) | |||||||||
ISSN: | 1365-2966 | |||||||||
Official Date: | June 2023 | |||||||||
Dates: |
|
|||||||||
Volume: | 522 | |||||||||
Number: | 2 | |||||||||
Page Range: | pp. 2145-2170 | |||||||||
DOI: | 10.1093/mnras/stad1103 | |||||||||
Status: | Peer Reviewed | |||||||||
Publication Status: | Published | |||||||||
Access rights to Published version: | Open Access (Creative Commons) | |||||||||
Date of first compliant deposit: | 4 August 2023 | |||||||||
Date of first compliant Open Access: | 4 August 2023 | |||||||||
RIOXX Funder/Project Grant: |
|
|||||||||
Related URLs: |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year