Presentation #353.03 in the session “Computational Augmentation to Observations”.
The WFC3 photometry team presents a new set of UVIS and IR zeropoints that incorporate improvements in the HST CALSPEC models as well as an increase in the Vega reference flux (Bohlin et al. 2020). The UVIS calibration includes new corrections for temporal changes in the detector sensitivity derived from over 10 years of monitoring data, improving the computed chip-sensitivity ratio and encircled energy values (Calamida et al. 2020). The IR zeropoints change primarily due to the new models, and they incorporate new flat fields in the calibration of the flux standards (Bajaj et al. 2020). The updated P-flats correct for spatial sensitivity residuals up to 0.5% in the center of the detector and up to 2% at the edges (Mack et al. 2020). The new 2020 zeropoints are available on the WFC3 Photometric Calibration webpage, and the team provides a Jupyter Notebook to show how to work with the new UVIS time-dependent solutions.