Non-equilibrium Equation of State in stellar atmospheres

التفاصيل البيبلوغرافية
العنوان: Non-equilibrium Equation of State in stellar atmospheres
المؤلفون: Anusha, L. S., van Noort, M., Cameron, R. H.
المصدر: ApJ, 911, 71 (2021)
سنة النشر: 2021
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics
الوصف: In the stellar chromospheres, radiative energy transport is dominated by only the strongest spectral lines. For these lines, the approximation of local thermodynamic equilibrium (LTE) is known to be very inaccurate, and a state of equilibrium cannot be assumed in general. To calculate the radiative energy transport under these conditions, the population evolution equation must be evaluated explicitly, including all time-dependent terms. We develop a numerical method to solve the evolution equation for the atomic-level populations in a time-implicit way, keeping all time-dependent terms to first order. We show that the linear approximation of the time dependence of the populations can handle very large time steps without losing the accuracy. We reproduce the benchmark solutions from earlier, well-established works in terms of non-LTE kinetic equilibrium solution and typical ionization/recombination time-scales in the solar chromosphere.
Comment: 42 pages, 8 figures
نوع الوثيقة: Working Paper
DOI: 10.3847/1538-4357/abe45d
URL الوصول: http://arxiv.org/abs/2104.13650
رقم الأكسشن: edsarx.2104.13650
قاعدة البيانات: arXiv
الوصف
DOI:10.3847/1538-4357/abe45d