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The Solar H and K Lines

1970; Institute of Physics; Volume: 82; Linguagem: Inglês

10.1086/128904

1538-3873

Jeffrey L. Linsky, E. H. Avrett,

Solar and Space Plasma Dynamics

ASTRONOMICAL SOCIETY OF THE PACIFIC Vol. 82 April 1970 No. 485 THE SOLAR H AND K LINES JEFFREY L. LINSKY Joint Institute for Laboratory Astrophysics of the National Bureau of Standards and the University of Colorado AND EUGENE H. AVRETT Smithsonian Astrophysical Observatory Harvard College Observatory itory 22, 1970 We review our current understanding of the formation of the Ca ii H and K resonance and infi-ared triplet subordinate lines in the sun in view of the wedth of observations of these lines and the devdopment of non-LTE line formation theory. We descrihe the low- and high-spatial resolution data of these lines on the solar disk, off the limb, and in stellar spectra. We also describe obseiwations of the analogous Mg ii resonance lines. We review the various explanations proposed for the features of the lines the reversal, limb darkening, plage and spot profiles, and the anomalous line ratios. Line profiles are according to a first-order steady-state theoiy in which we assume a one-component atmosphere in hydrostatic , noncoherent scattering, and a five -level atom and 'im representation for Ca ii. The chromospheric model chosen is to be representative nither than definitive, biit it profiles of all five a microwave continuum in agreement with observations at the of the disk. We then extensions of this first-order theory.