aXe-2.3

aXe-2.3 is part of STSDAS 3.14, which was released in August 2011. Within STSDAS, aXe resides in the sub-package 'analysis.slitless.axe'.

Along with the release of aXe v2.3 there is also an updated version of the aXe User Manual (pdf format). In addition, the most recent version of the aXe Cookbook (pdf format) may also be helpful when running the software.

Release notes

• Fixed a bug in "drzprep" that was causing 2D stamp images to have the wrong size (too short in the x/dispersion direction) when setting DRZRESOLA in the .config file to value smaller than the physical pixel size, in order to oversample the drizzled image.
• Fixed a bug in "drzprep" that was causing the calculated errors for spectra extracted from sub-sampled 2D images with axedrizzle to be too high by about a factor of 6.
• Modified the behavior of low-level routines called by the "axeprep" task so that it no longer quits with an error if it encounters an object in the input object list (IOL) with mag=99 (which is put there by SExtractor when it can't compute a magnitude for an object). It will now only issue a warning message and continue with processing. Entries for these objects will be ignored anyway by later aXe processing step due to the fact that their magnitudes exceed the MMAG_EXTRACT limit in the .config file.
• Fixed a bug in the "axedrizzle" task to prevent a divide-by-zero error for object spectra that have all of their pixels rejected due to excessive contamination.
• Upgraded the syntax of Python "raise" error statements in several modules to conform to new Python 2.7 syntax rules.
• Modified the drizzle method used by the "axedrizzle" task to check for input/output file names that are >80 characters long, in order to prevent the IRAF drizzle task from crashing on long file names.
• Upgraded several methods within the "axeprep" task to replace calls to IRAF tasks imcopy, imrename, imarith, imexpression, and imstatistics with equivalent Python, PyFITS, and numpy procedures. axeprep is now completely free of IRAF tasks.
• Removed all calls to IRAF tasks from the drizzleobjects module and replaced them with equivalent Python and PyFITS file utilities and numpy array arithmetic.
• Removed all calls to IRAF tasks imcopy, imrename, and imexpression from the fcubeobjs module and replaced them with equivalent Python, PyFITS, and numpy operations. fcubeprep still contains a call to the IRAF/STSDAS dither package task "blot".