Low levels of sulphur dioxide contamination of Venusian phosphine spectra
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
New analysis is presented of the 1.1 mm wavelength absorption lines in Venus’ atmosphere that suggested the presence of phosphine. We retrieve a sulphur dioxide observation from the JCMT archive that was simultaneous within a few days of the PH3 1-0 spectrum obtained in 2017 June, and demonstrate via a radiative transfer calculation that contamination of PH3 by SO2 was ≈10 per cent. We also present ALMA 2019 spectra of PH3 1-0 and an SO2 transition acquired simultaneously, and infer that SO2 line-contamination was ≲2 per cent (for the least-noisy half of the planetary disc). The contamination-subtracted ALMA and JCMT spectra (of 6–8σ sigma confidence) are now consistent with similar absorption-depths at the two epochs. The two values span −1.9(±0.2) 10−4 of the continuum signal (which was re-estimated for ALMA), albeit for differing planetary areas. This suggests that the abundance attributed to phosphine in Venus’ atmosphere was broadly similar in 2017 and 2019.
Date Issued
2022-08-01
Date Acceptance
2022-05-20
Citation
Monthly Notices of the Royal Astronomical Society, 2022, 514 (2), pp.2994-3001
ISSN
0035-8711
Publisher
Oxford University Press
Start Page
2994
End Page
3001
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
514
Issue
2
Copyright Statement
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This is a pre-copy-editing, author-produced version of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Jane S Greaves, Paul B Rimmer, Anita M S Richards, Janusz J Petkowski, William Bains, Sukrit Ranjan, Sara Seager, David L Clements, Clara Sousa Silva, Helen J Fraser, Low levels of sulphur dioxide contamination of Venusian phosphine spectra, Monthly Notices of the Royal Astronomical Society, Volume 514, Issue 2, August 2022, Pages 2994–3001 is available online at: https://doi.org/10.1093/mnras/stac1438
Subjects
Astronomy & Astrophysics
ATMOSPHERE
NO EVIDENCE
Physical Sciences
planets and satellites: individual: Venus
radio lines: planetary systems
Science & Technology
Publication Status
Published
Date Publish Online
2022-05-30