aXe is PyRAF/IRAF software which is comprised of several tasks and is distributed as a subpackage of the Space Telescope Data Analysis System (STSDAS) under analysis.slitless.axe. New releases of STSDAS become available approximately twice a year. More frequent updates and bug fixes are available in IRAFX, the development version of STSDAS, which is released weekly. Download and installation information for the STSDAS package can be found at STSDAS Home, and for IRAFX at http://stsdas.stsci.edu/irafx.
Updates Being Tested in IRAFX
(Click on version number for detailed release notes and bug reports.)
|aXe-2.X||2013-03-28||STScI: iolprep bug fix implemented|
|aXe-2.X||2013-03-07||STScI: Updates for Astrodrizzle in iolprep and fcubeprep|
Official Releases through STSDAS
(Click on version number for detailed release notes.)
|aXe-2.3||2011-08-23||ST-ECF: replacement of IRAF calls with equivalent Python, PyFITS, and numpy procedures; bug fixes|
|aXe-2.1||2010-07-15||ST-ECF: optimized and tested for WFC3 grism data|
Detailed Release Notes
- Available via IRAFX (the STSDAS testing environment).
- aXe was originally designed to support Multidrizzle style astrometric information. Current (aXe v2.3) and earlier versions of the software rely on output files from the Multidrizzle process to transform object pixel coordinates between the user supplied "drizzled" direct image and corresponding spectral images. We are currently working on updating aXe to accommodate the use of new Astrodrizzle products, and maintain back-compatability with Multidrizzle. Updates to iolprep and fcubeprep are being tested.
- Bug Report 2013-03-13 (IRAFX 2013-03-07): The output catalogs produced by iolprep inadvertently drops the first entry for the x,y image coordinates with the result that the remaining x,y coordinate entries are then offset by one.
- Bug fix for iolprep reported on 2013-03-13 available via IRAFX 2013-03-28 and later.
- Part of STSDAS 3.14, which was released in August 2011.
- 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".
- Part of STSDAS 3.13, which was released in January 2011.
- Also released in July 2010 as the external PyRAF/IRAF package taxe21.
- Extensively used and tested in the reduction of Wide Field Camera 3 (WFC3) grism data.
- Extended aXedrizzle to be able to detect deviant pixel values in the same way MultiDrizzle does for direct imaging. This new functionality was developed for and tested on WFC3 data. Using it for other instruments, such as ACS, cannot be guaranteed to produce meaningful results; tuning of the input parameters is strongly advised.
- Starting with aXe version 2.1 and aXeSIM version 1.4, the two packages have been united on the code level. As a consequence, the package taxe21 automatically contains taxesim14 and vice versa.