iraf.net

I'm trying to select FITS MEF files based upon information that is split between the PHDU and the HDUs. For whatever reason, the file from the (Gemini) archive has INHERIT=F. I thought clever use of FITS kernel features would allow me to use hselect to create a list of images. As you can see, the keywords OBJECT and OBSTYPE reside in the PHDU, and CCDSUM in the extensions:

cl\$this->_split2($m[0]) hselect S20060715S0059.fits[0] "$I object obstype ccdsum" yes
S20060715S0059.fits[0] Bias BIAS

cl\$this->_split2($m[0]) hselect S20060715S0059.fits[1] "$I object obstype ccdsum" yes
S20060715S0059.fits[1] "2 2"

Switching on inheritance gives me OBSTYPE and CCDSUM, but not OBJECT:

cl\$this->_split2($m[0]) hselect S20060715S0059.fits[1,inherit=yes] "$I object obstype ccdsum" "obstype=='BIAS'"
S20060715S0059.fits[1,inherit=yes] BIAS "2 2"

Searching explicitly on OBJECT generates an error:
cl\$this->_split2($m[0]) hselect S20060715S0059.fits[1,inherit=yes] "$I object obstype ccdsum" "object=='Bias'"
ERROR: Image header parameter not found (object)

Is OBJECT somehow special in the IRAF FITS kernel? Is there a way to search simultaneously on values of all these keywords?

The OBJECT keyword isn't special in the FITS sense, i.e. it isn't reserved. However, it is considered to be the image title string and so is handled specially by the various kernels. Try using 'i_title' instead of 'OBJECT' in your HSELECT command and you should come up with the string.

Note, you might also try using the '?=' string match operator in your selection expression instead of the boolean '==' if you have problems.