Extract CXO Data (extract-chandra)#

Pipeline module to generate \(500–8000\) eV images, PSF maps, and extracted spectra from a Chandra X-ray Observatory (CXO) event file.

Automates the standard CIAO workflow:

  1. Locate the user’s Conda environment.

  2. Locate the appropriate aspect solution (.asol1.fits) and mask (.msk1.fits) files.

  3. Run dmcopy to filter CCD 7 events in \(500–8000\) eV and bin to a smaller image.

  4. Create a PSF map at 1.4967 keV with 90% encircled-energy fraction.

  5. Run specextract to build source and background spectra (NUM_CTS grouping), applying correct weights.

Positional arguments:

  • COND_ENV : Name of the Conda environment to check against $CONDA_DEFAULT_ENV.

  • EVT_FILE : Path to the Chandra event file.

  • SRC_REG : Source region (filename or literal sky region).

  • BKG_REG : Background region (filename or literal sky region).

  • OUTDIR : Optional directory for outputs (defaults to EVT_FILE directory).

Options:
--help

Show help message

Output files (inside OUTDIR):

  • spec{obsid}_bkg.arf

  • spec{obsid}_bkg.rmf

  • spec{obsid}_bkg.pi

  • spec{obsid}.arf

  • spec{obsid}.rmf

  • spec{obsid}.pi

  • spec{obsid}.corr.arf

  • spec{obsid}_grp.pi - the spectrum file that will be used in SpectrumFit

Note

Assuming that the event file is inside obsid/primary/event.fits, the obsid is fundamentally the parent of the parent directory of the event file.

Usage formula:
>>> extract-chandra <COND_ENV> <EVT_FILE> <SRC_REG> <BKG_REG> [OUTDIR]
Usage examples:
>>> extract-chandra myenv /data/obs/1234/primary/event.fits src.reg bkg.reg
>>> extract-chandra myenv /data/obs/1234/primary/event.fits src.reg bkg.reg ./output
>>> extract-chandra -h # for help
Requirements:

  • CIAO (including dmcopy, mkpsfmap, specextract) installed.

  • CONDA_DEFAULT_ENV set to the requested environment name.