231 citations · 944 across the 16 of their papers we have counts for
16 papers
Near-instantaneous Atmospheric Retrievals and Model Comparison with FASTER
Anna Lueber, Konstantin Karchev, Chloe Fisher +3
In the era of the James Webb Space Telescope (JWST), the dramatic improvement in the spectra of exoplanetary atmospheres demands a corresponding leap forward in our ability to anal…
Parameter degeneracies associated with interpreting HST WFC3 transmission spectra of exoplanetary atmospheres
Aline Novais, Chloe Fisher, Luan Ghezzi +3
The Wide Field Camera 3 (WFC3) instrument on the Hubble Space Telescope has provided an abundance of exoplanet spectra over the years. These spectra have enabled analysis studies u…
Information content of JWST spectra of WASP-39b
Anna Lueber, Aline Novais, Chloe Fisher +1
WASP-39b was observed using several different JWST instrument modes and the spectra were published in a series of papers by the ERS team. The current study examines the information…
Intercomparison of Brown Dwarf Model Grids and Atmospheric Retrieval Using Machine Learning
Anna Lueber, Daniel Kitzmann, Chloe E. Fisher +4
Understanding differences between sub-stellar spectral data and models has proven to be a major challenge, especially for self-consistent model grids that are necessary for a thoro…
How do we optimally sample model grids of exoplanet spectra?
Chloe Fisher, Kevin Heng
The construction and implementation of atmospheric model grids is a popular tool in exoplanet characterisation. These typically vary a number of parameters linearly, containing one…
The Effect of Stellar Contamination on Low-resolution Transmission Spectroscopy: Needs Identified by NASA's Exoplanet Exploration Program Study Analysis Group 21
Benjamin V. Rackham, Néstor Espinoza, Svetlana V. Berdyugina +58
Study Analysis Group 21 (SAG21) of NASA's Exoplanet Exploration Program Analysis Group (ExoPAG) was organized to study the effect of stellar contamination on space-based transmissi…
Titanium oxide and chemical inhomogeneity in the atmosphere of the exoplanet WASP-189b
Bibiana Prinoth, H. Jens Hoeijmakers, Daniel Kitzmann +21
The temperature of an atmosphere decreases with increasing altitude, unless a shortwave absorber exists that causes a temperature inversion. Ozone plays this role in the Earth`s at…
HELIOS-K 2.0 Opacity Calculator and Open-source Opacity Database for Exoplanetary Atmospheres
Simon L. Grimm, Matej Malik, Daniel Kitzmann +12
Computing and using opacities is a key part of modeling and interpreting data of exoplanetary atmospheres. Since the underlying spectroscopic line lists are constantly expanding an…
Information content of JWST-NIRSPEC transmission spectra of warm Neptunes
Andrea Guzmán-Mesa, Daniel Kitzmann, Chloe Fisher +7
Warm Neptunes offer a rich opportunity for understanding exo-atmospheric chemistry. With the upcoming James Webb Space Telescope (JWST), there is a need to elucidate the balance be…
Supervised Machine Learning for Intercomparison of Model Grids of Brown Dwarfs: Application to GJ 570D and the Epsilon Indi B Binary System
Maria Oreshenko, Daniel Kitzmann, Pablo Marquez-Neila +6
Self-consistent model grids of brown dwarfs involve complex physics and chemistry, and are often computed using proprietary computer codes, making it challenging to identify the re…
Interpreting High-Resolution Spectroscopy of Exoplanets Using Cross-Correlations and Supervised Machine Learning
Chloe Fisher, H. Jens Hoeijmakers, Daniel Kitzmann +4
We present a new method for performing atmospheric retrieval on ground-based, high-resolution data of exoplanets. Our method combines cross-correlation functions with a random fore…
How Much Information Does the Sodium Doublet Encode? Retrieval Analysis of Non-LTE Sodium Lines at Low and High Spectral Resolutions
Chloe Fisher, Kevin Heng
Motivated by both ground- and space-based detections of the sodium doublet in the transmission spectra of exoplanetary atmospheres, we revisit the theory and interpretation of sodi…
A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b
H. J. Hoeijmakers, D. Ehrenreich, D. Kitzmann +16
Context: KELT-9 b exemplifies a newly emerging class of short-period gaseous exoplanets that tend to orbit hot, early type stars - termed ultra-hot Jupiters. The severe stellar irr…
Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) - II. A broadened sodium feature on the ultra-hot giant WASP-76b
J. V. Seidel, D. Ehrenreich, A. Wyttenbach +18
High-resolution optical spectroscopy is a powerful tool to characterise exoplanetary atmospheres from the ground. The sodium D lines, with their large cross sections, are especiall…
Retrieval analysis of 38 WFC3 transmission spectra and resolution of the normalisation degeneracy
Chloe Fisher, Kevin Heng
A comprehensive analysis of 38 previously published Wide Field Camera 3 (WFC3) transmission spectra is performed using a hierarchy of nested-sampling retrievals: with versus withou…
Supervised Machine Learning for Analysing Spectra of Exoplanetary Atmospheres
Pablo Marquez-Neila, Chloe Fisher, Raphael Sznitman +1
The use of machine learning is becoming ubiquitous in astronomy, but remains rare in the study of the atmospheres of exoplanets. Given the spectrum of an exoplanetary atmosphere, a…