Why is there an instrument map over channels 42 to 201, but not one over channels 20 to 201? Why are there no maps for channels above 201?

(3/15/94)

The answer to the first question is that Steve originally constructed the instrument maps for his own use. He chose channel ranges that were convenient for the problems that he wished to address. Later, he realized that these maps, and the program using these instrument maps to generate exposure maps, might be of general interest.

The answer to the second question is that there are very few counts above channel 201, and these are dominated by the particle background. An instrument map above channel 201 would be of a statistical quality too low to be useful.

Select another question related to this topic

Select another FAQ topic Return to the ROSAT GOF