Date: Fri, 19 Jan 2018 21:07:46 GMT
Subject: Pixel-Unit of psfgen output image
Full_Name: Alex Kolodzig
Submission from: (NULL) (220.127.116.11)
What is the pixel-unit of the psfgen output image?
psfgen image=Image_Binned.fits useodf=no region='(X,Y) IN box( 27418.28,
27084.62, 4800, 4800 )' instrument=M1 ccdnr=1 node=PRIMARY
cammode=PrimeFullWindow filter=Open ccdtemp=120 camtemp=120 temptrack=yes
starttime=1999-12-10T14:32:00.000 duration=0 level=ELLBETA parameter=0
random=yes binning=0 ccf='' ccflog=no energy=1000 weight=1 theta=-1 phi=-1
rotate=-1 coortype='' xsize=0 ysize=0 output=output.fits -w 1 -V 4
I tried as an input-image several images with different pixel-binning (e.g.
[1,2,4] arcsec/pixel, created with evselect) but the corresponding output-images
remain identical. So to me it appears that the image-pixel-binning from the
input-image are not adopted at all.
Further, if I don't specify xsize & ysize and use as region a box-size (see
example) of 4800 x 4800 [sky-pixels] (4 x 4 [arcmin]), I get an
output-image-dimension of 437x437 [img-pixels] and that's independent of the
detector (and image-pixel-binning) of the input-image. The image-size increases
linearly with the box-size but it is not clear to me how 4800 sky-pixels and 437
If 4800 sky-pixels corresponds to 437 img-pixels then I get ~0.55
arcmin/img-pixels. Is that suppose to be like that? I couldn't find anything
about this in the SAS documentation.
Even stranger is that 437 * 1.1 arcsec = ~8 arcmin, where 1.1 arcsec is the
CCD-pixel-size of MOS. So, I though that the pixel-unit is given in CCD-pixels
and my output-image is just twice the size of my box-size. However, why do I get
the same output-image-dimensions for PN was well, where the CCD-pixel-size is
4.1 arcsec ?
Thanks a lot in advance for your help
SAS release: xmmsas_20170719_1539-16.1.0 (sasversion-1.2)
Compiled on: Fri Jul 28 01:07:14 CEST 2017
Compiled by: firstname.lastname@example.org
Platform : RHEL6.8 64