Detectability of atmospheric features of Earth-like planets in the habitable zone around M dwarfs

التفاصيل البيبلوغرافية
العنوان: Detectability of atmospheric features of Earth-like planets in the habitable zone around M dwarfs
المؤلفون: Wunderlich, F., Godolt, M., Grenfell, J. L., Städt, S., Smith, A. M. S., Gebauer, S., Schreier, F., Hedelt, P., Rauer, H.
المصدر: A&A 624, A49 (2019)
سنة النشر: 2019
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Earth and Planetary Astrophysics
الوصف: We investigate the detectability of atmospheric spectral features of Earth-like planets in the habitable zone (HZ) around M dwarfs with the future James Webb Space Telescope (JWST). We use a coupled 1D climate-chemistry-model to simulate the influence of a range of observed and modelled M-dwarf spectra on Earth-like planets. The simulated atmospheres served as input for the calculation of the transmission spectra of the hypothetical planets, using a line-by-line spectral radiative transfer model. To investigate the spectroscopic detectability of absorption bands with JWST we further developed a signal-to-noise ratio (S/N) model and applied it to our transmission spectra. High abundances of CH$_4$ and H$_2$O in the atmosphere of Earth-like planets around mid to late M dwarfs increase the detectability of the corresponding spectral features compared to early M-dwarf planets. Increased temperatures in the middle atmosphere of mid- to late-type M-dwarf planets expand the atmosphere and further increase the detectability of absorption bands. To detect CH$_4$, H$_2$O, and CO$_2$ in the atmosphere of an Earth-like planet around a mid to late M dwarf observing only one transit with JWST could be enough up to a distance of 4 pc and less than ten transits up to a distance of 10 pc. As a consequence of saturation limits of JWST and less pronounced absorption bands, the detection of spectral features of hypothetical Earth-like planets around most early M dwarfs would require more than ten transits. We identify 276 existing M dwarfs (including GJ 1132, TRAPPIST-1, GJ 1214, and LHS 1140) around which atmospheric absorption features of hypothetical Earth-like planets could be detected by co-adding just a few transits. We show that using transmission spectroscopy, JWST could provide enough precision to be able to partly characterise the atmosphere of Earth-like TESS planets around mid to late M dwarfs.
Comment: 18 pages, 10 figures
نوع الوثيقة: Working Paper
DOI: 10.1051/0004-6361/201834504
URL الوصول: http://arxiv.org/abs/1905.02560
رقم الأكسشن: edsarx.1905.02560
قاعدة البيانات: arXiv
الوصف
DOI:10.1051/0004-6361/201834504