The Importance of Optical Wavelength Data on Atmospheric Retrievals of Exoplanet Transmission Spectra
Abstract
Exoplanet transmission spectra provide rich information about the chemical composition, clouds, and temperature structure of exoplanet atmospheres. Most exoplanet transmission spectra only span infrared wavelengths (≳1 μm), which can preclude crucial atmospheric information from shorter wavelengths. Here, we explore how retrieved atmospheric parameters from exoplanet transmission spectra change with the addition of optical data. From a sample of 14 giant planets with transit spectra from 0.3–4.5 μm, primarily from the Hubble and Spitzer space telescopes, we apply a free chemistry retrieval to planetary spectra for wavelength ranges of 0.3–4.5 μm, 0.6–4.5 μm, and 1.1–4.5 μm. We analyze the posterior distributions of these retrievals and perform an information content analysis, finding wavelengths below 0.6 μm are necessary to constrain cloud scattering slope parameters (
- Publication:
-
The Astronomical Journal
- Pub Date:
- May 2024
- DOI:
- 10.3847/1538-3881/ad3454
- arXiv:
- arXiv:2403.07801
- Bibcode:
- 2024AJ....167..240F
- Keywords:
-
- Exoplanet atmospheres;
- Transmission spectroscopy;
- Hubble Space Telescope;
- 487;
- 2133;
- 761;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 26 pages, 12 figures. Accepted for publication in the Astronomical Journal