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.