F8601 - Modelling of stellar atmospheres
Jiří Kubát, AsÚ AV ČR Ondrejov, kubat@sunstel.asu.cas.cz
exam requirements, PřF MU Brno, spring semester 2021
• Basic general equations of stellar atmospheres
• Grey atmosphere: Hopf function, two-step grey atmosphere, backwarming, mean opacities (flux mean opacity, Rosseland mean opacity)
• Static LTE model atmospheres: hydrostatic equilibrium, energy equilibrium (radiative equilibrium, convection), Unsold-Lucy tempertaure correction method, convective instability criteria, modelling of convection
• Static NLTE model atmospheres: overview of equations, discretization of equations and their solution, complete linearization method, application of the accelerated lambda iteration method, spherically symmetric model atmospheres, NLTE heating
• Opacity in model atmospheres: absorption, emission and scattering, line blanketing and its treatment in LTE and NLTE
• Analysis of stellar spectra: curves of growth, spectral classification, application of model atmospheres in analysis of stellar spectra, radiative diffusion, stellar rotation, one-dimensional models of circumstellar disks
• Stellar wind: types of stellar winds, isothermal stellar wind and its solution, effect of additional forces in stellar winds, coronal wind, dust driven wind
• Line radiatively driven wind: mechanism of wind acceleration and momentum transfer, radiative acceleration, its determination and limiting cases, CAK solution and its properties, determination of terminal wind velocities and mass-loss rates, stability of stellar wind, inhomogeneous stellar wind
• Multidimensional model atmospheres
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Basic recommended literature
• Kubát, J., 2021, Základy fyziky hvězdných atmosfér, učební text v IS
• Hubeny, I., Mihalas, D., 2014, Theory of Stellar Atmospheres, Princeton University Press
• Mihalas, D., 1978, Stellar Atmospheres, 2nd ed., W. H. Freeman & Comp., San Francisco
• Lamers, H. J. G. L. M., Cassinelli, J. P., 1999, Introduction to Stellar Winds, Cambridge Univ. Press
Supplementary literature
• Gray, R. F, 2005, The Observation and Analysis of Stellar Photospheres, 3rd ed., Cambridge University Press
• Monier R., Smalley B., Wahlgren G., Stee Ph. (eds.), 2010, Non-LTE Line Formation for Trace Elements in Stellar Atmospheres, EAS Publ. Ser. Vol. 43
• Niemczura, E., Smalley, B., Pych, W. (eds.), 2014, Determination of Atmospheric Parameters ofB-, A-, F- and G-Type Stars, Springer Verlag Berlin