The *bmask.fits files provide status information for each pixel in the input image. During extraction, pixels masked as “fatal” do not contribute to the spectrum. By default, the online pipeline defines bits 7, 12, 13,and 14 as fatal. In the Extract module, the user can change the definition of fatal bitmask conditions using the pull down menu. This change may improve the fidelity of features in the final spectrum or, more often, the cosmetic appearance of the continuum.
The definition of bit-setting conditions in the *bmask.fits files are given in Table 1.6.1. For a full discussion of the bitmask, see Appendix B of this manual and the IRS Instrument Handbook.
