Wide Field Camera 3 Instrument Handbook for Cycle 19 - Space ...

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Table of Contents
6.8 UVIS Sensitivity .....................................................................99
6.8.1 Limiting Magnitudes............................................................99
6.9 Other Considerations for UVIS Imaging ........................100
6.9.1 Gain and Full-well Saturation............................................100
6.9.2 Cosmic Rays and Hot Pixels..............................................100
6.9.3 Charge-Transfer Efficiency ...............................................101
6.9.4 Image Persistence ..............................................................101
6.9.5 Shutter-Induced Vibration .................................................101
6.9.6 Droplets..............................................................................102
6.9.7 Optical Anomalies .............................................................102
6.10 UVIS Observing Strategies..............................................103
6.10.1 Dithering Strategies .........................................................103
6.10.2 Parallel Observations .......................................................104
Chapter 7: IR Imaging with WFC3 .......................105
7.1 WFC3 IR Imaging ................................................................105
7.2 Specifying an IR Observation............................................106
7.3 IR Channel Characteristics .................................................106
7.4 IR Field Geometry ................................................................107
7.4.1 Field of View and Pixel Size .............................................107
7.4.2 Geometric Distortion .........................................................107
7.4.3 Coordinate Systems ...........................................................107
7.4.4 Subarrays ...........................................................................109
7.4.5 Apertures............................................................................110
7.5 IR Spectral Elements............................................................111
7.5.1 Filter and Grism Summary ................................................111
7.5.2 Filter Blue Leaks................................................................116
7.5.3 Ghosts ................................................................................117
7.6 IR Optical Performance.......................................................117
7.6.1 PSF Width and Sharpness..................................................118
7.6.2 Encircled and Ensquared Energy.......................................119
7.6.3 Other PSF Behavior and Characteristics ...........................122
7.7 IR Exposure and Readout ...................................................123
7.7.1 Exposure Time...................................................................123
7.7.2 MULTIACCUM Mode......................................................123
7.7.3 MULTIACCUM Timing Sequences:
Full Array Apertures..............................................................124
7.7.4 MULTIACCUM Timing Sequences:
Subarray Apertures ................................................................128