Updated PyRAF DBSP Pipeline
by eric
When I started doing optical observing in my postdoc, I was unpleasantly surprised at how difficult it was to learn to reduce the data. Most optical astronomers use a venerable package called IRAF, which may charitably be called “user antagonistic.” There is a Python wrapper, PyRAF, which mutes some of the annoyances but is no easier to use if you’re not already an IRAF expert.
Using a PyRAF script originally by Branimir Sesar, I extended, generalized, and documented a pipeline (available here) for reducing long-slit spectra from the Double-Beam Spectrograph (DBSP) of the Palomar 200-inch. It abstracts away many of the IRAF details to enable smooth reduction. It’s useful both for quick-look classification spectra as well as moderate-precision (few km/s) radial velocity work. Because it relies heavily on the filename and header conventions of DBSP, it would require extensive revision to use with another instrument. However, I am advertising it in hope it will be of use to others.
The version (0.2.0) I released today overcomes several annoyances. It automatically sets the dispersion parameters needed by autoidentify for arbitrary gratings and angles. I’ve added a modified version of doslit to minimize repetitive prompting of the user (see here for details). I added quicklook and batch processing scripts for fast, minimally-interactive reductions. And I expanded the documentation, although it’s probably still not complete enough to help a true novice.