view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Anomalous broadening of the CaII K line in spicules. Athay, R. Grant Abstract Caii K lzne ~ spicules. Observations of the profiles of the H~, Hp, H~, D3 and K lines for polar spicules suggest a spicule model in which the hydrogen, Hei and Caii atoms producing the observed lines are well-mixed, but in which the Caii ions have a non-thermal component of velocity not shared by hydrogen and Hei. An alternative model in which the hydrogen and Caii atoms producing the Balmer lines and the K line are physically separated by temperature stratification from the Hei atoms producing the D3 line satisfies some aspects of the data and allows hydrogen and Caii to share the same non-thermal velocity field. However, this alternative model is not compatible with the relative intensities of the Ho~ and D3 lines, nor with the absence of the strong lines of such ions as Srii and T~ii. The Hfl, H~ and D3 profiles are gaussian, and for the majority of spicules the half-widths for a given line are the same to within the probable errors in the observations. The profiles of these lines indicate a kinetic temperature of 50,0000 and a non-thermal velocity component of about 7 km~sec. The Ha profile is apparently broadened to some extent by self-absorption, which is consistent with the above model. The K line, however, appears to be broadened by a non-thermal velocity component of about 30 km/sec, which corresponds to the mean spicule velocity. It is suggested that the broadening of the K line is due either to the spiralling of the Caii ions about magnetic lines of force oriented at some angle to the spicule motion, or to the forced oscillations of the Caii ions by perturbations in a magnetic field lying in the direction of the spicule motion. High Altitude Observatory University of Colorado Boulder, Colo. Publication: The Astronomical Journal Pub Date: October 1959 DOI: 10.1086/107938 Bibcode: 1959AJ.....64..323A full text sources ADS |