Saved in:
| Main Authors: | , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2512.04265 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912748359647232 |
|---|---|
| author | Howard, Ward S. Kowalski, Adam F. Radica, Michael Flagg, Laura Vasilyev, Valeriy Rackham, Benjamin V. Mendoza, Guadalupe Tovar MacGregor, Meredith A. Shapiro, Alexander I. Taylor, Jake Coulombe, Louis-Philippe Lim, Olivia Lafreniere, David |
| author_facet | Howard, Ward S. Kowalski, Adam F. Radica, Michael Flagg, Laura Vasilyev, Valeriy Rackham, Benjamin V. Mendoza, Guadalupe Tovar MacGregor, Meredith A. Shapiro, Alexander I. Taylor, Jake Coulombe, Louis-Philippe Lim, Olivia Lafreniere, David |
| contents | Although TRAPPIST-1's temperate planets have the highest transmission signals of any known system, flares contaminate 50-70% of transits at the 1000 ppm level, far above 100 ppm secondary atmospheres. Efforts to mitigate flare contamination and assess impacts on radiation environments are each hampered by a lack of empirical spectral analysis and physics-based modeling. We present spectrotemporal analysis and radiative-hydrodynamic modeling of 5.5 hr of NIRISS and NIRSpec observations of 6 TRAPPIST-1 flares of 2.2-8.7x10^30 erg. Flare lines and continua are characterized using grid searches of RADYN beam-heating models spanning 10$^4\times$ in electron beam parameters. Best-fit models indicate these flares result from moderate-intensity beams with emergent electron fluxes of 10^12 erg s^-1 cm^-2 and energies $\leq$37 keV, although all models over-predict the Paschen jump. These models predict XUV, FUV, and NUV counterparts to the infrared peak fluxes of 8.9-28.9x10^27, 4.3-13.9x10^26, and 3.4-11.4x10^27 erg s^-1, respectively. Scaling the flare rate into the XUV suggests flaring contributes 1.35$_{-0.15}^{+2.0}\times$ quiescence yr$^{-1}$. We bin integrations of similar flare effective temperature to construct fiducial flare spectra from 2000-4500 K in order to develop separate empirical and RADYN-based mitigation pipelines. Both pipelines are applied to all 5.5 hr of R=10 data, resulting in maximum residuals from 1-2.8$μ$m of 100-140 ppm and typical residuals of 54$\pm$14 and 65$\pm$17 ppm for the empirical and RADYN-based pipelines, respectively. Injection testing supports 3$σ$ detection capability for CO2 atmospheres with features of 150-250 ppm, with weak evidence (BF$\approx$3) still obtained at 130 ppm. Our results motivate multi-wavelength observations to improve model fidelity and test high-energy predictions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_04265 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Separating flare and secondary atmospheric signals with RADYN modeling of near-infrared JWST transmission spectroscopy observations of TRAPPIST-1 Howard, Ward S. Kowalski, Adam F. Radica, Michael Flagg, Laura Vasilyev, Valeriy Rackham, Benjamin V. Mendoza, Guadalupe Tovar MacGregor, Meredith A. Shapiro, Alexander I. Taylor, Jake Coulombe, Louis-Philippe Lim, Olivia Lafreniere, David Earth and Planetary Astrophysics Solar and Stellar Astrophysics Although TRAPPIST-1's temperate planets have the highest transmission signals of any known system, flares contaminate 50-70% of transits at the 1000 ppm level, far above 100 ppm secondary atmospheres. Efforts to mitigate flare contamination and assess impacts on radiation environments are each hampered by a lack of empirical spectral analysis and physics-based modeling. We present spectrotemporal analysis and radiative-hydrodynamic modeling of 5.5 hr of NIRISS and NIRSpec observations of 6 TRAPPIST-1 flares of 2.2-8.7x10^30 erg. Flare lines and continua are characterized using grid searches of RADYN beam-heating models spanning 10$^4\times$ in electron beam parameters. Best-fit models indicate these flares result from moderate-intensity beams with emergent electron fluxes of 10^12 erg s^-1 cm^-2 and energies $\leq$37 keV, although all models over-predict the Paschen jump. These models predict XUV, FUV, and NUV counterparts to the infrared peak fluxes of 8.9-28.9x10^27, 4.3-13.9x10^26, and 3.4-11.4x10^27 erg s^-1, respectively. Scaling the flare rate into the XUV suggests flaring contributes 1.35$_{-0.15}^{+2.0}\times$ quiescence yr$^{-1}$. We bin integrations of similar flare effective temperature to construct fiducial flare spectra from 2000-4500 K in order to develop separate empirical and RADYN-based mitigation pipelines. Both pipelines are applied to all 5.5 hr of R=10 data, resulting in maximum residuals from 1-2.8$μ$m of 100-140 ppm and typical residuals of 54$\pm$14 and 65$\pm$17 ppm for the empirical and RADYN-based pipelines, respectively. Injection testing supports 3$σ$ detection capability for CO2 atmospheres with features of 150-250 ppm, with weak evidence (BF$\approx$3) still obtained at 130 ppm. Our results motivate multi-wavelength observations to improve model fidelity and test high-energy predictions. |
| title | Separating flare and secondary atmospheric signals with RADYN modeling of near-infrared JWST transmission spectroscopy observations of TRAPPIST-1 |
| topic | Earth and Planetary Astrophysics Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2512.04265 |