D..25 September, 2003 (AE Version 3.0)

• AE revised to run under CIAO 3.0. Earlier versions of CIAO are NOT SUPPORTED.

• AE now requires the ``30sep2003'' or later version of the TARA package.

• Format of ``catalog'' files revised--see §7.2.1. Construction of source names moved outside of CONSTRUCT_REGIONS stage to decouple source name from current estimate of source position.

• Revised PSF construction
  • Revising binning and extent of PSF images (generated in CONSTRUCT_REGIONS stage) to better match the PSF sizes.

  • Revised blurring of PSF images from 0.35 to 0.21 arcsec to better match performance of Chandra aspect system--see §5.2.

  • PSF images from a previous AE run are now re-used when possible, greatly speeding up CONSTRUCT_REGIONS stage when only PSF fraction is being changed.

• Revised CHECK_POSITIONS stage--see §7.17:
  • Added Maximum Likelihood reconstruction of each source neighborhood. Peak of reconstruction image saved for possible use as source position estimate.

  • Source neighborhood image is now energy filtered to reduce background.

  • Source neighborhood image filename changed from source.img to neighborhood.img.

• Revised EXTRACT_EVENTS/EXTRACT_SPECTRA stages:
  • Added computation and plotting of adaptively smoothed light curve and median energy time series--see §7.9.

  • Added note about using observer-supplied extraction regions, e.g. to extract sources suffering from pileup--see §7.7.

  • Added keywords EMAP_NUM, EMAP_AVG, EMAP_MED, EMAP_MIN, EMAP_MAX to characterize the exposure map values found inside the source extraction region--see §7.9.

  • Added optional input WARNING_REGION_FILENAME--see §7.7.

  • Added statistical errors on position (X_DATA,Y_DATA) estimated from data--see §7.7.

  • Fixed potential inaccuracy in EXPOSURE keyword assigned by dmextract--see §5.4.

• Improved method for applying mask regions to create ``Swiss-cheese'' background event list--see §7.13.

• Revised convention for supplying ARF correction curves--see §7.10.

• Added optional automatic selection of minimum spectral group size--see §7.18.

• Released example recipe for a complex, multi-observation AE reduction--see §7.

• Added note about discarding unused event list columns to reduce execution time--see §7.3.

Some of these changes are not backwards compatible with extraction file trees produced by earlier AE versions. If you are working with a dataset previously extracted by AE keep in mind:

• If EXTRACT_SPECTRA is re-run you must also re-run the EXTRACT_BACKGROUNDS stage, and vice versa.
• Before re-running CHECK_POSITIONS you must re-run the EXTRACT_EVENTS stage.
• The following AE output file names are obsolete: source.img, source.arf.