XMM-Newton Science Analysis System: User Guide

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Next: 6.7 Analysing OM data Up: 6.6 Running the OM data processing Previous: 6.6.2 Example of fast mode data processing

6.6.3 Example of grism data processing

As it has been pointed out, OM grism data are image mode data. Since tracking corrections are not applied to grism data, spacecraft and summary files are needed:

0472_0125910501_OMS00500WDX.FIT  - Exposure priority window file
0472_0125910501_OMS00500IMI.FIT  - Exposure image file with grism data

and the process will be run in the following way

step1> omprep set=0472_0125910501_OMS00500IMI.FIT \
              pehset=0472_0125910501_OMX00000PEH.FIT \
              nphset=0472_0125910501_OMX00000NPH.FIT \
              wdxset=0472_0125910501_OMS00500WDX.FIT \
              outset=g0125910501OMS005IMAGEI0000.FIT \

The input image corresponds to a user defined window. In the case of full frame low resolution exposures, the task omcomb must be run beforehand and its output image be used as input for omprep

step2> ommodmap set=g0125910501OMS005IMAGEI0000.FIT \
                mod8product=yes \
                mod8set=g0125910501OMS005MOD8MP0000.FIT \
                outset=g0125910501OMS005IMAGE_0000.FIT \
                outflatset=g0125910501OMS005FLAFLD0000.FIT \
                nsig=3 nbox=16 mod8correction=1

step3> omgprep set=g0125910501OMS005IMAGE_0000.FIT \
               outset=p0125910501OMS005RIMAGE0000.FIT \

This undistorted and rotated image is the one from which the spectrum, or spectra, will be extracted.

step4> omdetect set=p0125910501OMS005RIMAGE0000.FIT \
                regionfile=g0125910501OMS005REGION0001.ASC \
                outset=p0125910501OMS005SWSRLI0001.FIT \

The source spectra have been detected. They can be checked by overplotting the region file on the rotated image, using ds9.

step5> omatt set=p0125910501OMS005RIMAGE0000.FIT \
             sourcelistset=p0125910501OMS005SWSRLI0001.FIT \
             ppsoswset=g0125910501OMS005SIMAGE0000.FIT \
             usecat=no rotateimage=yes tolerance=3 maxradecerr=1 maxrmsres=1.5

All detected spectra have been assigned RA and Dec. A sky, north aligned image is also produced.

Spectral extraction will be done now

step6> omgrism set=p0125910501OMS005RIMAGE0000.FIT \
               sourcelistset=p0125910501OMS005SWSRLI0001.FIT \
               outset=p0125910501OMS005SPECTR0000.FIT \
               bkgoffsetleft=6 bkgwidthleft=-6 bkgoffsetright=6 \
               bkgwidthright=-6 spectrumhalfwidth=-6 spectrumsmoothlength=0 \
               extractionmode=0 extractfieldspectra=no \
               outspectralistset=p0125910501OMS005SPECLI0000.FIT \
               regionfile=p0125910501OMS005REGION0001.ASC \
               spectraregionfile=p0125910501OMS005SPCREG0001.ASC \

Target spectrum, or all spectra in the field of view if


is used, are extracted and calibrated.

Finally, the results can be plotted.

step7> omgrismplot set=p0125910501OMS005SPECTR0000.FIT \
                   binsize=1 plotdevice=/PS \
                   plotfile=g0125910501OMS005SPECTR0000.PS \
                   scalebkgplot=no plotflux=2 \
                   spectraregionfile=p0125910501OMS005SPCREG0001.ASC \
                   regionplotfile=p0125910501OMS005SPCREG0001.PS \

A PDF version of the plot is also produced.

next up previous contents
Next: 6.7 Analysing OM data Up: 6.6 Running the OM data processing Previous: 6.6.2 Example of fast mode data processing
European Space Agency - XMM-Newton Science Operations Centre