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Me in Honolulu, following a successful observing run at the Keck facility.

Nicholas Borsato

From Sweden to Australia, I'm on a quest to unveil the secrets of alien atmospheres.

Me in Honolulu, following a successful observing run at the Keck facility.

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

Author

  • N. W. Borsato
  • H. J. Hoeijmakers
  • B. Prinoth
  • B. Thorsbro
  • R. Forsberg
  • D. Kitzmann
  • K. Jones
  • K. Heng

Summary, in English

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.

Department/s

  • Astrophysics
  • eSSENCE: The e-Science Collaboration

Publishing year

2023

Language

English

Publication/Series

Astronomy and Astrophysics

Volume

673

Document type

Journal article

Publisher

EDP Sciences

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • Planets and satellites: atmospheres
  • Planets and satellites: gaseous planets
  • Techniques: spectroscopic

Status

Published

ISBN/ISSN/Other

  • ISSN: 0004-6361