16586

This is a continuation of programs 11433 (SMOV) comma 11915 (Cy 17) comma 12338 (Cy 18) comma 12712 (Cy 19) comma 13098 (Cy 20) comma 13587 (Cy 21) comma 14029 (Cy 22) comma 14391 (Cy23) comma 14548 (Cy24) comma 14998 (Cy25) comma 15591 (Cy26) comma 15731 (Cy27) comma and 16411 (Cy28). We study the stability and structure of the IR channel flat field images through all filter elements. Flats are monitored comma to capture any temporal trends and delta flats are produced. High signal observations will provide a map of the pixel-to-pixel flat field structure comma as well as identify the positions of any dust particles. This version contains a full set of IR filter exposures once in the middle of the cycle. In addition we will acquire 3 exposures in each of the broadband filters F105W comma F110W comma F125W comma F140W comma and F160W twice during the cycle. This work builds on the ISR of Ryan and Baggett (2015-011) and Ryan (2019-06). ------ Calibration Justification ------- The target electrons per pixel is 40 comma 000 - 60 comma 000 comma so that the Poisson noise of an individual pixel and a single exposure will be 0.5% comma comparable to or smaller than any individual astronomical image made by WFC3 IR. With 2 well-exposed flats per medium- and narrow-band filter comma the Poisson-limited noise after combining 2 individuals will be virgul1.4x smaller. For the broad-band filters comma we can combine 3 exposures to produce bi-monthly flats comma or combine a total of 18 exposures for a extremely low noise flats in the case temporal variations are limited. Analysis results will be detailed in an ISR.