UV Photometry Table

These four UV filters have values for PHTFLAM1 (inverse sensitivity for UVIS 1) set so that their PHTRATIO (PHTRATIO') matches the count ratio of the two detectors (COUNTRATES_RATIO).

For UVIS1 fluxes, multiply the UVIS1 count rate by PHOTFLAM. For UVIS2 fluxes, multiply the UVIS2 count rate by PHTFLAM1. For more details, please see ISR 2017-07 and ISR 2021-04.

For precise photometry, the user may wish to "back out" the inverse sensitivity ratio scaling, done by CALWF3, applying separate inverse sensitivities (PHTFLAM1 and PHTFLAM2) to calibrate photometry separately in each detector.

FILTER PIVOT1 PHTFLAM1' ERROR1' PHTRATIO' PHTFLAM1 ERROR1 PIVOT2 PHTFLAM2 ERROR2 COUNTRATES_RATIO PHTRATIO

F200LP

4971.86 5.5896e-20  2.1761e-22 0.9148 5.1234e-20 6.0032e-22 4875.10  5.1134e-20 5.9509e-22 0.921233 

0.9980

F218W

2228.04 1.4745e-17 8.9354e-20 0.7752 1.4664e-17 9.6609e-20 2223.72  1.1430e-17 1.1093e-19 0.778101 

0.7795

F225W

2372.05 4.6667e-18  1.5668e-20 0.8146  4.5849e-18 6.2529e-21 2358.39 3.8015e-18  4.2937e-21 0.812978

0.8291

F275W

2709.69 3.2489e-18 1.1509e-20 0.9384 3.2227e-18 5.1180e-21 2703.30  3.0488e-18  5.9952e-21 0.937221

0.9460


 

Last Updated: 06/02/2023

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