D..19 June, 2004 (AE Version 3.34)

• AE now requires the ``24 May, 2004'' or later version of the IDL Astronomy User's Library (http://idlastro.gsfc.nasa.gov/).

• Fixed a bug that led to systematic overestimation of flux for some sources in multi-observation extractions. Prior to this release if a source's extraction region contained no in-band counts (not even background counts) then no extraction was performed for that observation. Since the ignored observation's exposure time was not included in the flux calculations (either in AE or in XSPEC) the source's flux was overestimated.

  If you have an existing AE extraction you can identify sources suffering from this problem in several ways:

  • The observation directories suffering this problem will contain files named neighborhood.evt and source.evt but will not contain source.pi.

  • If a log of the messages AE produced when /EXTRACT_SPECTRA was run is available this message indicates that an extraction was aborted: ``EXTRACTION SKIPPED: no in-band data found in source region''.

  • The number of observations AE extracted for each source is plotted in the /MERGE_OBSERVATIONS, /PLOT stage. If you have some way of knowing how many observations there should be for each source then you can determine which sources suffer from aborted extractions.

• Fixed a bug that sometimes caused an incorrect PSF to be used to build reconstructed images in the CHECK_POSITIONS Stage.

  If you have an existing AE extraction you can identify sources suffering from this problem in two ways:

  • If a log of the messages AE version 3.19 produced when /CHECK_POSITIONS was run is available this message will appear for sources suffering from this problem: ``Rebinned multi-ObsId data image to ...''

  • If you rerun /CHECK_POSITIONS using AE version 3.34 then any source producing the message ``Rebinning multi-ObsId data and multi-ObsId PSF images by 2 ...'' probably suffered from this problem in the prior run.

• Released draft recipe for extracting piled up sources--see §7.

• Keyword REGION_FILE added to SHOW_REGIONS stage and controls implemented to navigate through catalog (§7.8).

• Keyword OBS_REGION_FILENAME added to EXTRACT_EVENTS/EXTRACT_SPECTRA stages (§7.7).

• A richer set of photometry statistics has been implemented (§5.10).

• Fixed mistake in computation of MEAN_ARF keyword in obs.stats. (The MEAN_ARF column in source.photometry is not affected.)

• Improved support for C-statistic in XSPEC. See new keyword /CSTAT in §7.18.