Saved in:
Bibliographic Details
Main Authors: Piskunov, Nikolai, Rains, Adam D., Boldt-Christmas, Linn
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2509.12737
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915496613380096
author Piskunov, Nikolai
Rains, Adam D.
Boldt-Christmas, Linn
author_facet Piskunov, Nikolai
Rains, Adam D.
Boldt-Christmas, Linn
contents Our ability to observe, detect, and characterize exoplanetary atmospheres has grown by leaps and bounds over the last 20 years, aided largely by developments in astronomical instrumentation; improvements in data analysis techniques; and an increase in the sophistication and availability of spectroscopic models. Over this time, detections have been made for a number of important molecular species across a range of wavelengths and spectral resolutions. Ground-based observations at high resolution are particularly valuable due to the high contrast achievable between the stellar spectral continuum and the cores of resolved exoplanet absorption features. However, the model-independent retrieval of such features remains a major hurdle in data analysis, with traditional methods being limited by both the choice of algorithm used to remove the non-exoplanetary components of the signal, as well as the accuracy of model template spectra used for cross-correlation. Here we present a new algorithm TSD (Transmission Spectroscopy Decomposition) formulated as an inverse problem in order to minimize the number of assumptions and theoretically modelled components included in the retrieval. Instead of cross-correlation with pre-computed template exoplanet spectra, we rely on high spectral resolution and instrument stability to distinguish between the stellar, exoplanetary, and telluric components and velocity frames in the sequence of absorption spectra taken during multiple transits. We demonstrate the performance of our new method using both simulated and real K band observations from ESO's VLT/CRIRES+ instrument, and present results obtained from two transits of the highly-inflated super-Neptune WASP-107 b which orbits a nearby K7V star.
format Preprint
id arxiv_https___arxiv_org_abs_2509_12737
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle TSD: An inverse problem approach for recovering the exoplanetary atmosphere transmission spectrum from high-resolution spectroscopy
Piskunov, Nikolai
Rains, Adam D.
Boldt-Christmas, Linn
Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
Our ability to observe, detect, and characterize exoplanetary atmospheres has grown by leaps and bounds over the last 20 years, aided largely by developments in astronomical instrumentation; improvements in data analysis techniques; and an increase in the sophistication and availability of spectroscopic models. Over this time, detections have been made for a number of important molecular species across a range of wavelengths and spectral resolutions. Ground-based observations at high resolution are particularly valuable due to the high contrast achievable between the stellar spectral continuum and the cores of resolved exoplanet absorption features. However, the model-independent retrieval of such features remains a major hurdle in data analysis, with traditional methods being limited by both the choice of algorithm used to remove the non-exoplanetary components of the signal, as well as the accuracy of model template spectra used for cross-correlation. Here we present a new algorithm TSD (Transmission Spectroscopy Decomposition) formulated as an inverse problem in order to minimize the number of assumptions and theoretically modelled components included in the retrieval. Instead of cross-correlation with pre-computed template exoplanet spectra, we rely on high spectral resolution and instrument stability to distinguish between the stellar, exoplanetary, and telluric components and velocity frames in the sequence of absorption spectra taken during multiple transits. We demonstrate the performance of our new method using both simulated and real K band observations from ESO's VLT/CRIRES+ instrument, and present results obtained from two transits of the highly-inflated super-Neptune WASP-107 b which orbits a nearby K7V star.
title TSD: An inverse problem approach for recovering the exoplanetary atmosphere transmission spectrum from high-resolution spectroscopy
topic Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2509.12737