Line Profiles for λ=6173Å, by Roger K. Ulrich

This page is a copy of Professor Ulrich's webpage:

http://www.astro.ucla.edu/~ulrich/Fe_Profiles/021204/index.html

The following profiles were obtained on Dec. 4, 2002. These were done in quiet sun regions with the KDP analyzer in the beam. The circular polarization separated line profiles confirm that the field was small for these regions. Each profile is a composite obtained by combining the profiles from all 10 channels which scanned the line. The center of the 10-channel head was centered on the solar line so that channels on the edge of the head were offset from the line center. This produces a wider spectral range of measurement but also causes the edges of the profiles to be less significant than the center because the profile is sampled by progressively fewer channels until at the end only one is making the measurement. The scanning is alternatively red to blue then blue to red. Each scan takes 15 seconds. For the profiles shown, the line movement is not tracked and all scans are combined into one. The sequence goes for 80 scans or 20 minutes. Thus all these profiles are smeared by the oscillations. The smeared profiles are available in tabular form for ρ=0, 45 and 60 degrees. The tables give wavelength offset in Å, the relative intensity and the number of spectral samples per reported point.The final profiles have been deconvolved using an instrumental profile derived from the unresolved absorption profile inserted by a non-magnetized sodium vapor cell. The resulting deconvolved profiles are shown in the plot below for three center-to-limb angles ρ=0, 45 and 60 degrees:

A detailed description of the system for line profile studies at the 150-foot tower on Mount Wilson can be found in the following reference: Ulrich, Roger K.; Webster, Larry; Boyden, John E.; Magnone, Nick; Bogart, Richard S., 1991, Solar Physics, 135, 211U