xcsao Example 1. Cross-correlating a Galaxy Spectrum

In this example, we will demonstrate the variety of intermediate graphical and printed information available when running xcsao. This may help the user to better understand how the task computes a redshift.
We will obtain a redshift from the spectrum of a galaxy with absorption features and Start with this image and click on [next] on each page to see all of the graphical displays xcsao produces for this example if the proper parameters are set. Click on [graphs] to select from a page of thumbnail images of all of the possible graphs which xcsao can generate in the course of processing this example. galaxy spectrum
The galaxy spectrum will be cross-correlated against a composite absorption line template ztemp spectrum
and a synthesized emission line template, using the parameters already set in xcsao.par. emtemp spectrum
The command
        cl> xcsao 22408 templates=ztemp,stemp
runs the task, and may, if switches are set, plot many intermediate graphs. If debug=yes, a lot of stuff is also sent to standard output (usually the terminal). The results are printed to the files listed in the parameter logfiles:
22408 Object: 0936+1659B 
RA: 09:36:48.00 Dec: 16:59:00.0 1950.0
1991-Apr-13 04:02:26.00 =HJD2448359.6920 BCV: -25.87
4609.6A- 6500.0A 2048x2 points, filter: 5 20 125 250 apodize 0.05 fit 0.5 best 1
Temp:        ztemp.imh vel:   0.00  tsh:   0.00 HCV:   0.00 Peak: 8228.15 h:0.254 R:   3.69 CZ: 8201.56 +/-  38.622 1 -el -tf +tc
Temp:       emtemp.imh vel:   0.00  tsh:   0.00 HCV:   0.00 Peak: -2687.8 h:0.060 R:   1.59 CZ: -2713.4 +/-  89.949 1 +hi -tf +tc
and displayed graphically on the device specified by device. summmary graph

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