XMM-Newton Science Analysis System


psfgen (psfgen-1.2) [xmmsas_20160201_1833-15.0.0]

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Example2: create one PSF

When a output file name is given in parameter output, psfgen will create a PSF and save it to the named file (overwrite). User should specify the requied energy band (energy) and accuracy level (level). The geometry parameters should be supplied as demostrated in Example1 4.1. For example,

psfgen region='(DETX, DETY) IN box(-12962,-579,1400,1600)' instrument=M2 output=m2psf.fits level=ELLBETA energy=4500

will create the PSF for 4500eV energy level on EMOS2 centred at TEL(648.114, 2.51136) with accuracy level ELLBETA and save it to 'm2psf.fits'.

All the setting parameters have default values (see Parameters section 6). So

psfgen output=psf.fits

works and 'psf.fits' is a PSF for 3000eV energy level on EMOS1 centred at TEL(0, 0) with accuracy level MEDIUM.

If the user is interested in the PSF of a particular source in MEDIUM level with energy level 6000eV. The easiest way is to select and save the source image to a fits file (e.g. 'source.fits') using xmmselect/evselect. And then use the following command:

psfgen image=source.fits output=source_psf.fits energy=6000

The file 'source_psf.fits' is the required PSF with the same size as 'source.fits' with the PSF centre in the middle. Therefore, when selecting the source, the centre of the source should be in the middle of the source image as well.