Comparing Tip of the Red Giant Branch Distance Scales: An Independent Reduction of the Carnegie-Chicago Hubble Program and the Value of the Hubble Constant

The tip of the red giant branch has been used to measure distances 500 nearby galaxies with Hubble Space Telescope (HST) which are available in Color-Magnitude Diagrams and Tip Red Giant Branch (CMDs/TRGB) catalog on Extragalactic Distance Database (EDD). Our established methods employed perform an independent reduction targets presented by Carnegie-Chicago Program (CCHP) series papers culminating Freedman (2021). distinct methodology involves modeling observed luminosity function asymptotic stars, differs from edge-detection algorithms CCHP. We find excellent agreement between for 11 hosts new imaging, all at D < 20 Mpc. However, we unable TRGB 4 5 that use archival data designed Cepheids, > 23 With two HST observations taken halo megamaser host NGC 4258, first same ACS F606W F814W filters post-servicing electronics SN Ia hosts, then calibrate our distance scale geometric distance. Using distances, a value Constant $H_{0}$ = 71.5 $\pm$ 1.8 km/s/Mpc when using either Pantheon or Carnegie Supernova Project (CSP) samples supernovae. In future, James Webb will extend measurements additional surface brightness fluctuation separate paths $H_{0}$.