Hamilton Thorium-Argon Spectrum (Dewar 4)
The overexposed Argon lines at the top of the image are a necessary
evil of the Th-Ar lamp. They may be partly suppressed by using a bg38
filter, but at the cost of also suppressing useful lines in the red.
Note that the image is shown here is windowed.
For orders and wavelengths of individual
lines, refer to Lick Observatory Technical Report #73,
The Hamilton Spectrograph TH-AR Atlas
by M. D. Shetrone (it's a green, paperbound book, copies of which
should be floating around in the 3-m and CAT control rooms).
The UCB astronomy department has also upublished an on-line,