ASCA PSF Analysis with 3C 273 SIS0 PV Data
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| 3C 273 S0 Observed |
3C 273 S0 Simulated
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This figure shows actual and simulated SIS0 images of 3C 273. The actual
observation was re-centered after every data gap longer that 1800 secs to
reduce blurring due to aspect errors. No background subtraction was done in
this image, and no background was added
to the simulated events. The position of the source was ~ 7.1' off-axis.
The images are logarithmic and are 11.2' by 11.2' (i.e., one ccd).
Comparison of the Observed Profile with xrt_psf_v2_0.fits and trace_asca
The plots below show the ratio of observed to predicted radial profiles.
Because 3C 273 is bright over the entire chip, the background was taken from
the caldb blank sky file 94nov/s0bgd_alli.evt. The profiles were computed
assuming this backgound (solid lines), plus the effect of subtracting the
background at 1/2 the level predicted by the blank sky events (dotted lines)
and without any background subtraction (dot-dashed lines).
0.4-10.0 keV
0.4-1.2 keV
1.2-2.2 keV
2.3-5.0 keV
5.0-10.0 keV
