The Mantis Network : III. Expanding the limits of chemical searches within ultra-hot Jupiters: New detections of Ca I, v I, Ti I, Cr I, Ni I, Sr II, Ba II, and Tb II in KELT-9 b
(2023) In Astronomy and Astrophysics 673.- Abstract
Cross-correlation spectroscopy is an invaluable tool in the study of exoplanets. However, aliasing between spectral lines makes it vulnerable to systematic biases. This work strives to constrain the aliases of the cross-correlation function to provide increased confidence in the detections of elements in the atmospheres of ultra-hot Jupiters (UHJs) observed with high-resolution spectrographs. We use a combination of archival transit observations of the UHJ KELT-9 b obtained with the HARPS-N and CARMENES spectrographs and show that it is possible to leverage each instrument's strengths to produce robust detections at a substantially reduced signal-to-noise. Aliases that become present at low signal-to-noise regimes are constrained... (More)
Cross-correlation spectroscopy is an invaluable tool in the study of exoplanets. However, aliasing between spectral lines makes it vulnerable to systematic biases. This work strives to constrain the aliases of the cross-correlation function to provide increased confidence in the detections of elements in the atmospheres of ultra-hot Jupiters (UHJs) observed with high-resolution spectrographs. We use a combination of archival transit observations of the UHJ KELT-9 b obtained with the HARPS-N and CARMENES spectrographs and show that it is possible to leverage each instrument's strengths to produce robust detections at a substantially reduced signal-to-noise. Aliases that become present at low signal-to-noise regimes are constrained through a linear regression model. We confirm previous detections of H I, Na I, Mg I, Ca II, Sc II, Ti II, Cr II, Fe I, and Fe II, and detect eight new species, Ca I, Cr I, Ni I, Sr II, and Tb II, at the 5δ level, and Ti I, V I, and Ba II above the 3δ level. Ionised terbium (Tb II) has never before been seen in an exoplanet atmosphere. We further conclude that a 5δ threshold may not provide a reliable measure of confidence when used to claim detections, unless the systematics in the cross-correlation function caused by aliases are taken into account.
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- author
- Borsato, N. W. LU ; Hoeijmakers, H. J. ; Prinoth, B. LU ; Thorsbro, B. LU ; Forsberg, R. LU ; Kitzmann, D. ; Jones, K. and Heng, K.
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Planets and satellites: atmospheres, Planets and satellites: gaseous planets, Techniques: spectroscopic
- in
- Astronomy and Astrophysics
- volume
- 673
- article number
- A158
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85161048747
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361/202245121
- language
- English
- LU publication?
- yes
- id
- e0b95ac1-dd79-403a-ae9d-f2cfcc582bf8
- date added to LUP
- 2023-08-21 15:43:16
- date last changed
- 2023-08-21 15:43:16
@article{e0b95ac1-dd79-403a-ae9d-f2cfcc582bf8, abstract = {{<p>Cross-correlation spectroscopy is an invaluable tool in the study of exoplanets. However, aliasing between spectral lines makes it vulnerable to systematic biases. This work strives to constrain the aliases of the cross-correlation function to provide increased confidence in the detections of elements in the atmospheres of ultra-hot Jupiters (UHJs) observed with high-resolution spectrographs. We use a combination of archival transit observations of the UHJ KELT-9 b obtained with the HARPS-N and CARMENES spectrographs and show that it is possible to leverage each instrument's strengths to produce robust detections at a substantially reduced signal-to-noise. Aliases that become present at low signal-to-noise regimes are constrained through a linear regression model. We confirm previous detections of H I, Na I, Mg I, Ca II, Sc II, Ti II, Cr II, Fe I, and Fe II, and detect eight new species, Ca I, Cr I, Ni I, Sr II, and Tb II, at the 5δ level, and Ti I, V I, and Ba II above the 3δ level. Ionised terbium (Tb II) has never before been seen in an exoplanet atmosphere. We further conclude that a 5δ threshold may not provide a reliable measure of confidence when used to claim detections, unless the systematics in the cross-correlation function caused by aliases are taken into account.</p>}}, author = {{Borsato, N. W. and Hoeijmakers, H. J. and Prinoth, B. and Thorsbro, B. and Forsberg, R. and Kitzmann, D. and Jones, K. and Heng, K.}}, issn = {{0004-6361}}, keywords = {{Planets and satellites: atmospheres; Planets and satellites: gaseous planets; Techniques: spectroscopic}}, language = {{eng}}, publisher = {{EDP Sciences}}, series = {{Astronomy and Astrophysics}}, title = {{The Mantis Network : III. Expanding the limits of chemical searches within ultra-hot Jupiters: New detections of Ca I, v I, Ti I, Cr I, Ni I, Sr II, Ba II, and Tb II in KELT-9 b}}, url = {{http://dx.doi.org/10.1051/0004-6361/202245121}}, doi = {{10.1051/0004-6361/202245121}}, volume = {{673}}, year = {{2023}}, }