You may want to look at the transfer streak (events that fall in the
same columns as the core of the source, but during readout). There
are some words about that in the POG, section 6.12.4 (of rev. 3.0).
See also figure 6.21, on page 101. Since the effective exposure
time is only 40 microsec per pixel instead of the few seconds of
the main image, strong sources can give un-piled-up data in this
streak.
Dick Edgar
>
>
> Dear all,
> this is my first mounth of work on a CHANDRA observation; I have an ACIS-I
> image which is strongly piled-up; in order to understand if there is
> evidence of an X-ray scattering halo, I'm trying to compare the surface
> brightness distribution (in different energy intervals) of my source with
> that of its own PSF, which of course depends on energy ("its" because I
> have calculated the PSF in the central point of my image through an
> interpolation of librarie PSFs, following the CIAO threads). I wonder how
> to normalize them...
> Does someone have suggestions to give me, please?
> thank you very much !
> Elena Gallo
>
>
-- ============================================================================= Richard J. Edgar edgar@head-cfa.harvard.edu | "It all depends, of course, Harvard-Smithsonian Center for Astrophysics | upon whether or not it depends 60 Garden St., MS 70, Cambridge, MA 02138 | or not, of course, if you take phone: (617)495-7249; fax: (617)495-7356 | my meaning." --John Woolley
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