Spitzer Documentation & Tools
IRS Instrument Handbook

8.2  Data Reduction Steps for IRS Spectroscopic Modules

The detailed procedure you should follow for reducing your data depends on the module used and on the type of source you are looking at.  However, the most basic reduction consists of five basic steps, described in Section 8.2.1 and shown schematically in Figure 8.1.  After examining the results of a basic reduction, you may find that further steps are necessary due to, for example, bad pixels (see Section 7.2.2) or latents (see Section 7.2.5).  We therefore provide a set of optional steps that you may add to your procedure to optimize your results.  Throughout this section, Mapping Mode refers to maps designed to recover spatial information on extended sources.  Users dealing with Mapping Mode observations designed to perform very deep observations of point sources may want to follow the guidelines for Staring Mode observations.


Figure 8.1 This flowchart describes the basic steps necessary to reduce IRS low-resolution spectra.  Additional flowcharts illustrating the 2D background subtraction procedure and how to clean up the 1D spectrum are provided in Figure 8.2 and Figure 8.3.


Figure 8.2 This flowchart illustrates how to subtract the background from your low-resolution 2D IRS spectrum.


Figure 8.3 This flowchart illustrates the main issues found with low-resolution IRS spectra.  These include latent charge (see Section 7.2.5), residual bad pixels (which can be corrected using IRSCLEAN; see Section 7.2.2), and fringes (which can be corrected using IRSFRINGE or SMART; see Section 7.3.7).