FLAMINGOS I Background Limited Exposure Times and Saturation Limits

The calculations of the time needed to become background (sky + telescope) limited are based on unverified sensitivities. The techniques and assumptions that go into these calculations are similar to those in the Gemini Integration Time Calculator (ITC) . Note that as a visitor instrument FLAMINGOS I is not supported as part of the ITC.

Below is a table showing the time required, in each filter, for the background count-rate to equal the square of the readout noise. See the detector page for more specific information on the FLAMINGOS I array.

The second table lists the exposure times needed to reach 50% full-well depth with each filter. To avoid problems with linearity, individual exposure times should not exceed these levels (allowing some room for objects detected above the sky).

The third table gives the count rates for a 15th magnitude star in each filter in units of e-/sec/pixel. The array suffers ~1% non linearity just above 70% well depth, so these numbers can guide maximum exposure times for bright objects.


Table 1: Time, in seconds, to reach BACKGROUND = READ NOISE SQUARED

J H K Ks
87.0 10.5 7.1 10.0


Table 2: Time in seconds for BACKGROUND to reach 50% full-well depth

J H K Ks
2812 338 230 324



Table 3: Count rates (e-/sec/pix) for a 15th magnitude star

J H K Ks
16444 19770 20137 17219


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Last update Aug 30, 2001 Michael Ledlow