APOGEE sees the light!

Above is the first spectrum taken with the SDSS-III APOGEE spectrograph, that for a krypton discharge lamp.

This spectrum was made under warm conditions and using a InGaAs detector with pixels two times larger than the actual APOGEE detectors will deliver. A series of separate images were taken, stepping along the dispersion direction in the spectrograph focal plane, and were then mosaic’ed together to make this final image. Several examples of these individual images are shown in the postage stamps in the upper corners. The lines in the spectrum are color coded by the final APOGEE detector on which they are expected to fall (blue, middle, red).

Analysis of this spectrum (by David Nidever), although undersampling the spectrograph resolution, suggests that the instrument is performing to specification.

Congratulations to the hardworking instrument team for this great progress!

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