Peering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet Atmospheres
Ground-based high-resolution cross-correlation spectroscopy (HRCCS; R ≳ 15,000) is a powerful complement to space-based studies of exoplanet atmospheres. By resolving individual spectral lines, HRCCS can precisely measure chemical abundance ratios, directly constrain atmospheric dynamics, and robus...
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astronomical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-3881/ada27e |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1823857994535796736 |
|---|---|
| author | Arjun B. Savel Megan Bedell Eliza M.-R. Kempton Peter C. B. Smith Jacob L. Bean Lily L. Zhao Kaze W. K. Wong Jorge A. Sanchez Michael R. Line |
| author_facet | Arjun B. Savel Megan Bedell Eliza M.-R. Kempton Peter C. B. Smith Jacob L. Bean Lily L. Zhao Kaze W. K. Wong Jorge A. Sanchez Michael R. Line |
| author_sort | Arjun B. Savel |
| collection | DOAJ |
| description | Ground-based high-resolution cross-correlation spectroscopy (HRCCS; R ≳ 15,000) is a powerful complement to space-based studies of exoplanet atmospheres. By resolving individual spectral lines, HRCCS can precisely measure chemical abundance ratios, directly constrain atmospheric dynamics, and robustly probe multidimensional physics. But the subtleties of HRCCS data sets—e.g., the lack of exoplanetary spectra visible by eye and the statistically complex process of telluric removal—can make interpreting them difficult. In this work, we seek to clarify the uncertainty budget of HRCCS with a forward-modeling approach. We present an HRCCS observation simulator, scope , ^5 that incorporates spectral contributions from the exoplanet, star, tellurics, and instrument. This tool allows us to control the underlying data set, enabling controlled experimentation with complex HRCCS methods. Simulating a fiducial hot Jupiter data set (WASP-77Ab emission with IGRINS), we first confirm via multiple tests that the commonly used principal component analysis does not bias the planetary signal when few components are used. Furthermore, we demonstrate that mildly varying tellurics and moderate wavelength solution errors induce only mild decreases in HRCCS detection significance. However, limiting-case, strongly varying tellurics can bias the retrieved velocities and gas abundances. Additionally, in the low signal-to-noise ratio limit, constraints on gas abundances become highly non-Gaussian. Our investigation of the uncertainties and potential biases inherent in HRCCS data analysis enables greater confidence in scientific results from this maturing method. |
| format | Article |
| id | doaj-art-9bf080397bef444c8e2fb5789baac9fc |
| institution | Kabale University |
| issn | 1538-3881 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj-art-9bf080397bef444c8e2fb5789baac9fc2025-02-11T17:03:56ZengIOP PublishingThe Astronomical Journal1538-38812025-01-01169313510.3847/1538-3881/ada27ePeering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet AtmospheresArjun B. Savel0https://orcid.org/0000-0002-2454-768XMegan Bedell1https://orcid.org/0000-0001-9907-7742Eliza M.-R. Kempton2https://orcid.org/0000-0002-1337-9051Peter C. B. Smith3https://orcid.org/0000-0002-9946-5259Jacob L. Bean4https://orcid.org/0000-0003-4733-6532Lily L. Zhao5https://orcid.org/0000-0002-3852-3590Kaze W. K. Wong6https://orcid.org/0000-0001-8432-7788Jorge A. Sanchez7https://orcid.org/0000-0002-9142-6378Michael R. Line8https://orcid.org/0000-0002-2338-476XCenter for Computational Astrophysics, Flatiron Institute , 162 Fifth Avenue, New York, NY 10010, USA; Astronomy Department, University of Maryland , College Park, 4296 Stadium Drive, College Park, MD 207842, USACenter for Computational Astrophysics, Flatiron Institute , 162 Fifth Avenue, New York, NY 10010, USAAstronomy Department, University of Maryland , College Park, 4296 Stadium Drive, College Park, MD 207842, USASchool of Earth and Space Exploration, Arizona State University , PO Box 871404, Tempe, AZ 85281, USADepartment of Astronomy & Astrophysics, University of Chicago, Chicago, IL 60637, USACenter for Computational Astrophysics, Flatiron Institute , 162 Fifth Avenue, New York, NY 10010, USACenter for Computational Astrophysics, Flatiron Institute , 162 Fifth Avenue, New York, NY 10010, USASchool of Earth and Space Exploration, Arizona State University , PO Box 871404, Tempe, AZ 85281, USASchool of Earth and Space Exploration, Arizona State University , PO Box 871404, Tempe, AZ 85281, USAGround-based high-resolution cross-correlation spectroscopy (HRCCS; R ≳ 15,000) is a powerful complement to space-based studies of exoplanet atmospheres. By resolving individual spectral lines, HRCCS can precisely measure chemical abundance ratios, directly constrain atmospheric dynamics, and robustly probe multidimensional physics. But the subtleties of HRCCS data sets—e.g., the lack of exoplanetary spectra visible by eye and the statistically complex process of telluric removal—can make interpreting them difficult. In this work, we seek to clarify the uncertainty budget of HRCCS with a forward-modeling approach. We present an HRCCS observation simulator, scope , ^5 that incorporates spectral contributions from the exoplanet, star, tellurics, and instrument. This tool allows us to control the underlying data set, enabling controlled experimentation with complex HRCCS methods. Simulating a fiducial hot Jupiter data set (WASP-77Ab emission with IGRINS), we first confirm via multiple tests that the commonly used principal component analysis does not bias the planetary signal when few components are used. Furthermore, we demonstrate that mildly varying tellurics and moderate wavelength solution errors induce only mild decreases in HRCCS detection significance. However, limiting-case, strongly varying tellurics can bias the retrieved velocities and gas abundances. Additionally, in the low signal-to-noise ratio limit, constraints on gas abundances become highly non-Gaussian. Our investigation of the uncertainties and potential biases inherent in HRCCS data analysis enables greater confidence in scientific results from this maturing method.https://doi.org/10.3847/1538-3881/ada27eExoplanet atmospheric compositionRadiative transfer simulationsHigh resolution spectroscopyInfrared spectroscopyAstronomy data modeling |
| spellingShingle | Arjun B. Savel Megan Bedell Eliza M.-R. Kempton Peter C. B. Smith Jacob L. Bean Lily L. Zhao Kaze W. K. Wong Jorge A. Sanchez Michael R. Line Peering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet Atmospheres The Astronomical Journal Exoplanet atmospheric composition Radiative transfer simulations High resolution spectroscopy Infrared spectroscopy Astronomy data modeling |
| title | Peering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet Atmospheres |
| title_full | Peering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet Atmospheres |
| title_fullStr | Peering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet Atmospheres |
| title_full_unstemmed | Peering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet Atmospheres |
| title_short | Peering into the Black Box: Forward Modeling of the Uncertainty Budget of High-resolution Spectroscopy of Exoplanet Atmospheres |
| title_sort | peering into the black box forward modeling of the uncertainty budget of high resolution spectroscopy of exoplanet atmospheres |
| topic | Exoplanet atmospheric composition Radiative transfer simulations High resolution spectroscopy Infrared spectroscopy Astronomy data modeling |
| url | https://doi.org/10.3847/1538-3881/ada27e |
| work_keys_str_mv | AT arjunbsavel peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT meganbedell peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT elizamrkempton peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT petercbsmith peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT jacoblbean peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT lilylzhao peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT kazewkwong peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT jorgeasanchez peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres AT michaelrline peeringintotheblackboxforwardmodelingoftheuncertaintybudgetofhighresolutionspectroscopyofexoplanetatmospheres |