Reconstructing the Extreme Ultraviolet Emission of Cool Dwarfs Using Differential Emission Measure Polynomials
| Autor: | Girish M. Duvvuri, J. Sebastian Pineda, Zachory K. Berta-Thompson, Alexander Brown, Kevin France, Adam F. Kowalski, Seth Redfield, Dennis Tilipman, Mariela C. Vieytes, David J. Wilson, Allison Youngblood, Cynthia S. Froning, Jeffrey Linsky, R. O. Parke Loyd, Pablo Mauas, Yamila Miguel, Elisabeth R. Newton, Sarah Rugheimer, P. Christian Schneider |
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| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
Extreme ultraviolet lithography Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Ultraviolet Astronomy Solar Extreme Ultraviolet Emission Ultraviolet astronomy Planet Stellar Activity 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Emission spectrum Stellar Chromospheres Stellar Atmospheres 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Stellar Coronae 0105 earth and related environmental sciences Physics Earth and Planetary Astrophysics (astro-ph.EP) Atmospheric escape Astronomy and Astrophysics Exoplanet Interstellar medium Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Low Mass Stars Extreme ultraviolet M Dwarf Stars Astrophysics::Earth and Planetary Astrophysics Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | The Astrophysical Journal, 913(1) |
| DOI: | 10.48550/arxiv.2102.08493 |
| Popis: | Characterizing the atmospheres of planets orbiting M dwarfs requires understanding the spectral energy distributions of M dwarfs over planetary lifetimes. Surveys like MUSCLES, HAZMAT, and FUMES have collected multiwavelength spectra across the spectral type's range of Teff and activity, but the extreme ultraviolet flux (EUV, 100 to 912 Angstroms) of most of these stars remains unobserved because of obscuration by the interstellar medium compounded with limited detector sensitivity. While targets with observable EUV flux exist, there is no currently operational facility observing between 150 and 912 Angstroms. Inferring the spectra of exoplanet hosts in this regime is critical to studying the evolution of planetary atmospheres because the EUV heats the top of the thermosphere and drives atmospheric escape. This paper presents our implementation of the differential emission measure technique to reconstruct the EUV spectra of cool dwarfs. We characterize our method's accuracy and precision by applying it to the Sun and AU Mic. We then apply it to three fainter M dwarfs: GJ 832, Barnard's Star, and TRAPPIST-1. We demonstrate that with the strongest far ultraviolet (FUV, 912 to 1700 Angstroms) emission lines, observed with Hubble Space Telescope and/or Far Ultraviolet Spectroscopic Explorer, and a coarse X-ray spectrum from either Chandra X-ray Observatory or XMM-Newton, we can reconstruct the Sun's EUV spectrum to within a factor of 1.8, with our model's formal uncertainties encompassing the data. We report the integrated EUV flux of our M dwarf sample with uncertainties between a factor of 2 to 7 depending on available data quality. Comment: 37 pages, 22 figures, and 5 tables. A citation to Woods et al. (2009) in Table 5 was altered to plain text because of issues with Arxiv's AutoTex processing, but the full reference is preserved in the bibliography |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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