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Last modified: 23 November 2021

URL: https://cxc.cfa.harvard.edu/ciao/bugs/mkarf.html

Bugs: mkarf


Table of Contents

Caveats


Caveats

Warnings related to missing SUM_2X2, OCLKPAIR, FEP_CCD, or ORC_MODE keywords

Users trying to run this tool with old versions of data products, those created with ASCDSVER less than version 8.4.2, may see warnings like


FITSIO status = 202: keyword not found in header
*** ERROR: *** Unable to get the value of `SUM_2X2' in /data/acisf04425_000N003_evt1.fits

Users should consult the Watch Out page for more information on this topic an information on how to upgrade their data products.

Comments and units are not always clear

The comments and units of the output ARF file has some keyword and column that do not follow the standards (eg "sec" instead of "s" for seconds). The data values and keyword/column names are correct.


Bugs fixed in CIAO 4.14

The following is a list of bugs that were fixed in the CIAO 4.14 software release.

Failure to include "frame store shadow" bad pixels

The ardlib default BPMASK does not include the new Fame Store Shadow bit (bit 17). For sources located at the bottom edges of detector this can result in an overestimate of the effective area.

More details can be found on the Caveats about ACIS Frame Store Shadow Bad Pixels page.

Incorrect Vignetting calibrations

The azimuthal angle (angle measured around the optical axis) used to compute the vignetting correction component of the effective area is incorrect. The vignetting correction varies azimuthally about the optical axis. The amplitude of the variation is a function of off-axis angle and is energy dependent; but typically varies up to a few percent.