Knowledgebase: CUBISM

In CUBISM, which calibration set should be used with which Spitzer IRS pipeline version?

As of this writing (March 2011), all data in the IRS archive have been reprocessed with version S18.18 of the IRS pipeline.

CUBISM version 1.8 defaults to a calibration set corresponding to pipeline version S18.18.

If you downloaded your data and built cubes some time ago with an older version of CUBISM, then the calibration set you used is saved in the CUBISM cpj file. Therefore, you are free to use CUBISM version 1.8 in order to access its new features without compromising your calibration. However, you should check the IRS pipeline history log in the IRS Instrument Handbook to see if there have been changes which could affect your science. In that case, you should download your newly-processed data from the archive and use the default calibration in CUBISM version 1.8 .

How does CUBISM render slit sizes?

The aperture shown in CUBISM is data-driven, and does not intend to represent the full slit. The width in the CUBISM visualization reflects that of the 1 pixel width wavesamp, which is set that way on purpose, reflecting the fact that in the cross-slit direction, you have a convolution of spectra and spatial information. It also uses the actual configured length of wavesamp pseudorectangles (not just some fiducial slit length number). So it's on the conservative side, whereas Spot's visualization is "generous" with the slit dimensions.

I am experiencing problems with colors in CUBISM. What do I do?

You may experience inconsistencies between the colors indicated in the CUBISM documentation and what you see on your screen if you have chosen to install the full source distribution of CUBISM.

If you have trouble with the colors looking strange on a 16 or 24-bit system, add:

device, DECOMPOSED=0, RETAIN=2

to your IDL startup file (whatever file the environment variable IDL_STARTUP points to).

Alternatively, you can install the VM version of CUBISM.