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Calibration Lamps

High Resolution Spectra

The table below shows high resolution calibration spectra of the lamps available at the observatory, taken with the 1200 lines/mm grating. These spectra were taken using an identical setup to the observatory found in the first year lab of the University of Birmingham. Also included are the line lists for each of the lamps which can be used in the Identify package of IRAF.

The settings used to take these spectra are given in tables under each of the plots, however when taking spectra at the observatory, the drum readings (for angle, slit width and Fcam) will differ from those shown.

Some lines in the Krypton spectra have not been well identified (in ranges 4210Å-5060Å and 4990Å-5820Å) however these plots have been included to give some indication of lines in these ranges.

IRAF includes several of its own line lists, although the lists do not always cover the range of wavelengths needed for the observation lab. Some useful lists include:-

• henear.dat - He, Ne and Ar.
• henearhres.dat - high resolution He, Ne and Ar.
• fear.dat - Ar (and Fe).

The Keck Observatory website also has some useful information and line lists.

Low Resolution Spectra

For some of the lamps, a low resolution spectrum has also been included in order to provide a more complete or wider ranging spectrum than given in the high resolution plots above. These were taken using the 150 lines/mm grating.

Cold Lamp Spectra

The relative intensities of some peaks may change as the lamp warms up, which can make lines more difficult to identify. The table below shows spectra of the Helium and Neon lamps taken within 5 minutes of the lamp being switched on. They have been taken with the same settings as the spectra listed above so that a direct comparison can be made.

Most of the relative intensities remain the same (although overall intensities differ). However some examples of differences can be seen in the Neon ranges 5370Å-6195Å and 6120Å-6945Å when compared with the spectra above.

PDF versions of all of the spectra can be found on the Printable Documents page.

All wavelength values have been taken from "Wavelength Tables" (Harrison, G. R; Massachuestts Institute of Technology).

More spectra, and line lists can also be found here.