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ROSAT Guest Observer Facility

What else should I notice from the hardcopy housekeeping?

(4/4/92)


The start and end of a GTI may be "contaminated" by high background, caused by the detector looking at the Earth limb before the target has fully risen. For background subtracted point sources, this contamination is generally not a problem (assuming the background subtraction is made using a bgd region where the degree of contamination is the same, e.g., an annulus around a point source located on-axis).

Further, there are 'afterpulses' visible in the background light curve (an upturn in the counts toward lower channels after the peak at about channel number 15 or so). Short-term enhancements are visible as a gradual increase in count rate over a few hour interval; long-term enhancements are visible as a gradual increase or decrease in the mean counts over day-length intervals.


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This file was last modified on Friday, 27-Jul-2001 14:59:27 EDT

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