Bugs: sky2tdet

Caveats
Bugs fixed in CIAO 4.4

Caveats

# sky2tdet (CIAO): ERROR: no non-null/0/nan pixels are in the input image

(02 Mar 2012)

The most likely cause of this error is that the region and energy filter supplied to sky2tdet do not select any events:

unix% dmlist "evt2.fits[sky=region(ciao.reg)][energy=300:2000]" counts
0

Workaround:

Adjust the energy filter for the WMAP to match that of your events. The range of event energies in the region can be found with dmstat:

unix% dmstat "evt2.fits[sky=region(ciao.reg)][cols energy]"
energy[eV]
min: 2231.7507324 @: 61
max: 7980.6259766 @: 35
mean: 4012.0070413
sigma: 1252.6216735
sum: 429284.75342
good: 107
null: 0

Bugs fixed in CIAO 4.4

The following is a list of bugs that were fixed in the CIAO 4.4 software release.

NaN values in the ARF if there are time header keywords with a 0 value (25 Apr 2011)

If any of the time keywords in the input file have an exposure time of 0 (i.e. it has been filtered out of the file), the output ARF will contain NaN values. This is because mkwarf doesn't properly handle the case there is flux in the WMAP but zero time for the chip.

Workaround:

Run the remove_extra_time_keywords script before running sky2tdet:

unix% remove_extra_time_keywords evt2.fits

The script, released in the 25 April scripts package removes any time keyword with an exposure time of 0 from the header of infile.