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 |