The global and local count-rate screening limits for each COS configuration are given in Table 10.1
. The limits are independent of observing mode (TIME-TAG or ACCUM
). Compliance with these limits must be checked for all proposed COS targets by means of the Exposure Time Calculator
(ETC), which issues warnings if they are exceeded. In Phase I, all proposed targets must be screened against these limits. In Phase II, the results of more detailed target and field checks must be submitted with the observing proposal; details are provided in Section 10.6
. Note that the local count rate limits given in Table 1.2
and the local count rate screening limits given in Table 10.1
are not applicable to the 1055 and 1096 cenwaves of the COS G130M grating. For those modes the local limit is 0.2 count/s/pixel for both predictable and irregular sources.