Daryl W Willmarth
Michael Fitzpatrick
National Optical Astronomy Observatories
950 N Cherry Avenue
P.O. Box 26732
Tucson, AZ 85726-6732

When the Westinghouse-style hollow cathode lamps became unavailable a few years ago, Photron lamps were readily available and have replaced most of the older lamps on Kitt Peak. These have somewhat different spectral line intensities which prompted the construction of a new ThAr atlas. The line list for this atlas is the same as for the Westinghouse lamp line list (see below), however not all the lines in that list may be present in the Photron lamp spectra. Users of high resolution spectrographs may want to consult the Westinghouse lamp web page since it has about four times the resolution of the Photron atlas.

This atlas consists of one long data file covering the wavelength region from 3,230Å - 10,540Å. The data were obtained using grating A with the Kitt Peak National Observatory 2.1m coude spectrograph . The light source was a Photron hollow cathode lamp, model P858AQ. The Tektronics 2k x 2k CCD T2KB was used as the detector. The data were extracted, and dispersion corrected using standard IRAF software. No attempt was made to establish an absolute intensity scale over the whole range of wavelengths. A line list is also available with identifications from Palmer and Engleman (1983) for Th and from Norlén (1973) for Ar.

λ Range (Å)OrderFilterResolution (λ/dλ)
3230 - 3630
3630 - 4230
4230 - 5470
5470 - 6965
6965 - 8100
8100 - 10540

After selecting a wavelength range, click on the 'Get Spectrum' button. After several seconds, a plot and line list will appear. The user has the option of displaying the plot, the line list, or both. There is also a downloading section where the unlabeled FITS data and the plot in Postscript format is available. The plot and line list is created from the IRAF task identify. A list of all the lines shown here may also be found in the IRAF linelists directory as the file thar.dat.

This main page also makes available the entire Atlas and Line List to be downloaded directly. (use Right Mouse Button to Save to Disk)

Choose a Wavelength Range and Display Options
(3200Å to 10550Å, no commas please)
Start Wavelength: End Wavelength:
Max Num Lines: Show Plot Show List

Palmer, B.A. and Engleman, R., Jr., 1983, Atlas of the Thorium Spectrum, Los Alamos National Laboratory, Los Alamos, New Mexico
Norlén, G., 1973, Physica Scripta, 8, 249.