Bibliographic Details
| Title: |
On the Robustness of Phosphine Signatures in Venus' Clouds |
| Authors: |
Greaves, Jane S., Bains, William, Petkowski, Janusz J., Seager, Sara, Sousa-Silva, Clara, Ranjan, Sukrit, Clements, David L., Rimmer, Paul B., Fraser, Helen J., Mairs, Steve, Currie, Malcolm J. |
| Source: |
Nature Astronomy 5.7 (2021): 726-728 |
| Publication Year: |
2020 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics |
| More Details: |
We published spectra of phosphine molecules in Venus' clouds, following open-science principles in releasing data and scripts (with community input leading to ALMA re-processing, now benefiting multiple projects). Some misconceptions about de-trending of spectral baselines have also emerged, which we address here. Using the JCMT PH3-discovery data, we show that mathematically-correct polynomial fitting of periodic ripples does not lead to "fake lines" (probability < ~1%). We then show that the ripples can be characterised in a non-subjective manner via Fourier transforms. A 20 ppb PH3 feature is ~5{\sigma} compared to the JCMT baseline-uncertainty, and is distinctive as a narrow perturber of the periodic ripple pattern. The structure of the FT-derived baseline also shows that polynomial fitting, if unguided, can amplify artefacts and so artificially reduce significance of real lines.
Comment: Response to: Snellen I. et al. Astron. Astroph., in press, arXiv:2010:09761 (2020); Villanueva G. et al. Nat. Ast. Matters Arising; arXiv:2010.14305 (2020); Thompson M. Mon. Not. Roy. Astron. Soc., in press, arXiv:2010.15118 (2020); Submitted to Nature Astronomy "Matters Arising" on Dec/10/2020 |
| Document Type: |
Working Paper |
| DOI: |
10.1038/s41550-021-01423-y |
| Access URL: |
http://arxiv.org/abs/2012.05844 |
| Accession Number: |
edsarx.2012.05844 |
| Database: |
arXiv |
