Meech, Annabella, Aigrain, Suzanne, Brogi, Matteo and Birkby, Jayne L. (2022) Applications of a Gaussian process framework for modelling of high-resolution exoplanet spectra. Monthly Notices of the Royal Astronomical Society, 512 (2). pp. 2604-2617. doi:10.1093/mnras/stac662 ISSN 1365-2966.

Preview

PDF WRAP-Applications-Gaussian-framework-modelling-high-resolution-exoplanet-spectra-22.pdf - Published Version - Requires a PDF viewer. Available under License Creative Commons Attribution 4.0. Download (1596Kb) | Preview

Request Changes to record.

Abstract

Observations of exoplanet atmospheres in high resolution have the potential to resolve individual planetary absorption lines, despite the issues associated with ground-based observations. The removal of contaminating stellar and telluric absorption features is one of the most sensitive steps required to reveal the planetary spectrum and, while many different detrending methods exist, it remains difficult to directly compare the performance and efficacy of these methods. Additionally, though the standard cross-correlation method enables robust detection of specific atmospheric species, it only probes for features that are expected a priori. Here we present a novel methodology using Gaussian process regression to directly model the components of high-resolution spectra, which partially addresses these issues. We use two archival CRIRES/VLT datasets as test cases, observations of the hot Jupiters HD 189733 b and 51 Pegasi b, recovering injected signals with average line contrast ratios of ∼4.37 × 10−3 and ∼1.39 × 10−3, and planet radial velocities ΔKp = 1.45 ± 1.53 km s−1 and ΔKp = 0.12 ± 0.12 km s−1 from the injection velocities respectively. In addition, we demonstrate an application of the GP method to assess the impact of the detrending process on the planetary spectrum, by implementing injection-recovery tests. We show that standard detrending methods used in the literature negatively affect the amplitudes of absorption features in particular, which has the potential to render retrieval analyses inaccurate. Finally, we discuss possible limiting factors for the non-detections using this method, likely to be remedied by higher signal-to-noise data.

Item Type:	Journal Article
Subjects:	Q Science > QA Mathematics Q Science > QB Astronomy
Divisions:	Faculty of Science, Engineering and Medicine > Science > Physics
SWORD Depositor:	Library Publications Router
Library of Congress Subject Headings (LCSH):	Extrasolar planets -- Atmospheres, Planets -- Spectra, Atmospheric radiation, Gaussian processes -- Data processing
Journal or Publication Title:	Monthly Notices of the Royal Astronomical Society
Publisher:	Oxford University Press (OUP)
ISSN:	1365-2966
Official Date:	May 2022
Dates:	Date Event May 2022 Published 12 March 2022 Available 2 March 2022 Accepted
Volume:	512
Number:	2
Page Range:	pp. 2604-2617
DOI:	10.1093/mnras/stac662
Status:	Peer Reviewed
Publication Status:	Published
Reuse Statement (publisher, data, author rights):	** Article version: AM ** From Crossref journal articles via Jisc Publications Router ** History: epub 12-03-2022; issued 12-03-2022. ** Licence for AM version of this article starting on 12-03-2022: https://creativecommons.org/licenses/by/4.0/
Access rights to Published version:	Open Access (Creative Commons)
Date of first compliant deposit:	14 November 2022
Date of first compliant Open Access:	14 November 2022
RIOXX Funder/Project Grant:	Project/Grant ID RIOXX Funder Name Funder ID UNSPECIFIED [STFC] Science and Technology Facilities Council http://dx.doi.org/10.13039/501100000271 865624 [ERC] Horizon 2020 Framework Programme http://dx.doi.org/10.13039/100010661 805445 [ERC] Horizon 2020 Framework Programme http://dx.doi.org/10.13039/100010661
Related URLs:	https://creativecommons.org/licenses/by/...

Request changes or add full text files to a record

Repository staff actions (login required)

View Item

Downloads