Spectral analysis of solar spicules

The spectral characteristics of solar limb spicules are investigated, using high dispersion emission spectra obtained through an observational program conducted by others at the Sacramento Peak Observatory. The tower telescope and echelle spectrograph were used to obtain time sequences of simultaneous spectra in various wavelength regions using an entrance slit tangent to the solar disc. Through photometric reduction, total intensities, spicule diameters, Doppler velocities, and profile halfwidths are measured. Using intensity ratios and line widths, temperatures and electron densities are estimated (T/sub e/ less than 25,0000K, 3 x 1010 cm-3 less than n/sub e/ less than 3 x 1011 cm-3). Large scale spicule expansions are ruled out, although possible expulsions or accretions of material are observed. Small differences in real diameters in various emission lines are a possibility. Corrections of the observations for atmospheric turbulence and variations in spectrograph slit heights are made. Halfwidths and Doppler shifts are found to vary in time similarly in Hα and ionized calcium emission lines. Inclinations of spectral emission lines are probably caused in varying degrees by velocity variations parallel and perpendicular to spicule axes, and by superposition of profiles of separate or multi-component structures