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MOPEX User's Guide - IRSA

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<strong>MOPEX</strong> User’s <strong>Guide</strong><br />

mosaic_mask.pl: Allows making of a mosaic “OR”-mask, and optionally a mask cube. See<br />

http://irsa.ipac.caltech.edu/data/SPITZER/docs/files/spitzer/mosaic_mask.p<br />

df for documentation. An example namelist is in<br />

cdf/mosaic_mask_I1_example.nl.<br />

mosaic_sed.pl: MIPS SED data reduction. This script performs interpolation and<br />

coaddition of MIPS SED (spectral energy distribution) images, and extracts<br />

the spectra. See<br />

http://irsa.ipac.caltech.edu/data/SPITZER/docs/files/spitzer/mosaic_sed.pdf<br />

for documentation.<br />

2.5 Which Modules Should I Choose?<br />

When running <strong>MOPEX</strong>, each data reduction step should be tailored to the dataset. Users do this<br />

by selecting certain modules to run, and setting the input parameters for those modules. The<br />

number of modules and parameters in <strong>MOPEX</strong> can be a little daunting, so here we give a short<br />

introduction to the most-used modules. Detailed descriptions of the modules can be found later in<br />

the manual.<br />

First-time users should start with the template namelists found in the File Menu, rather than trying<br />

to build up the name list in an empty pipeline. These templates are intended only as guides, and<br />

will need fine-tuning for use with your data. With experience, you will be able to include or<br />

exclude modules as needed and tune the input parameters for specific purposes. <strong>MOPEX</strong><br />

typically saves the results from each module in . These intermediate results can be<br />

examined to evaluate the performance at each step.<br />

For data reduction walk-throughs, including more advice on options to use with different data<br />

sets, see the Spitzer Data Analysis Cookbook. We stress that these are not exhaustive, and are<br />

continually being developed.<br />

2.5.1 Overlap (overlap.pl)<br />

The Overlap pipeline (run on the command line with the script overlap.pl) performs background<br />

matching (§8.5) on the input images, and is fully described in Chapter 4. It does not set the<br />

background level to zero, rather it adds (or subtracts) a constant to bring it to an average level.<br />

This process is recommended for Spitzer data, as there can be variation in the sky level that will<br />

lead to a patchy-looking final mosaic if not corrected, but this step may not be necessary if the<br />

BCDs downloaded from the Spitzer archive have already been background-subtracted, e.g. by<br />

<strong>MOPEX</strong>’s “Median” filtering.<br />

Overview of <strong>MOPEX</strong> 13<br />

Which Modules Should I Choose?

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