Goodman Comparison Lamps
Updated Mar 2021
The SOAR Instrument Support Boxes (ISBs) contain facility calibration units containing both continuum sources for flat fielding and line sources for wavelength calibration. 
The wavelength calibration lamps normally used with the Goodman spectrograph are: HgAr, CuHeAr, Ne, and Ar. An Fe lamp is also available.
The comparison lamps can be activated from the instrument GUI by you, or you can ask the Telescope Operator (TO) to do it for you from his technical GUI.
Note that you need to make a slow, substantial mouse click on the particular lamp in order for it to actually get the input and turn on or off (a quick click may make the green light go on or off but not turn on/off the lamp). If in doubt, check with the TO. The Fe lamp is not featured in the GUI and you need to ask the TO to rutn it ON/OFF for you. When obtaining comparison lamps, make sure you are in Spectroscopic Mode and that the TO has put the pickup mirror in.
In Figure 1 at below we show the CuHeAr arc lamp spectra for most of our pre-defined spectroscopic modes. NOTE: the 300 l/mm grating has now been replaced by the 400 l/mm grating.
In Figure 2 below we show the HgAr arc lamp spectra for most of our pre-defined spectroscopic modes. NOTE: the 300 l/mm grating has now been replaced by the 400 l/mm grating.
In the following table containing plots of the comparison lamps made with various gratings and setups. However, for the latest library of comparison lamp spectra, we advise you use the comparison lamp spectra at this link.
| Grating | Setup | Lamp | Wavelength Coverage of the Plot |
|---|---|---|---|
| 400 | M1 | HgAr | 3000-7000 (Full range) |
| 400 | M1 | HgAr | 3000-5000 (Zoom) |
| 400 | M1 | HgAr | 5000-7000 (Zoom) |
| 400 | M2 | HgAr | 5000-9000 (Full range) |
| 400 | M2 | HgAr | 5000-9000 (Zoomed/split) |
| 600 | UV,Blue,Mid,Red | HgAr | 3600-9000 (6 plots) |
| 600 | UV,Blue,Mid | CuHeAr | 3600-6500 |
| 930 | M1 | HgAr | 3000-4500 (Full range & zoom) |
| 930 | M2 | HgAr | 3750-5500 (Full range & zoom) |
| 930 | M3 | HgAr | 4750-6250 (Full range & zoom) |
| 930 | M4 | HgAr | 5500-7200 (Full range & zoom) |
| 930 | M5 | HgAr | 6400-8000 (Full range & zoom) |
| 930 | M6 | HgAr | 7250-8750 (Full range & zoom) |
| 930 | M2 | CuHeAr | 3750-5500 (Full range & zoom) |
| 930 | M3 | CuHeAr | 4750-6250 (Full range & zoom) |
| 930 | M4 | CuHeAr | 5500-7200 |
| 930 | M5 | CuHeAr | 6400-8000 |
| 930 | M6 | CuHeAr | 7250-8750 |
| 1200 | M5 | HgArNe | 3600-8700 (7 plots) |
| 1200 | M1,M2,M3,M4,M5,M6,M7 | CuHeAr | 3600-8700 (7 plots) |
| 2100 | 650nm (Littrow) | Ne | 6150-6720 |
Useful links:
The KPNO Spectral Atlas Central is a useful resource for comparison lamp spectra
