The Chicago Carnegie Hubble Program: Improving the Calibration of SNe Ia with JWST Measurements of the Tip of the Red Giant Branch

Understand

We present distances to ten supernova (SN) host galaxies determined via the red giant branch tip (TRGB) using JWST/NIRCAM and the F115W, F356W, and F444W bandpasses.

• Our analysis, including photometric catalog cleaning, adoption of disk light profiles, TRGB color slope estimation, and a novel technique for identifying the infrared TRGB, was conducted blinded.
• The new F115W TRGB distances agree well with our previously derived HST TRGB distances, differing by only 1 percent on average and 4 percent on a per-galaxy basis.
• The color-corrected F115W TRGB is therefore equally precise a method of distance measurement as, and offers unique advantages over, its color-insensitive, I-band counterpart.