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The Carnegie-Chicago Hubble Program (CCHP) is re-calibrating theextragalactic SN Ia distance scale using exclusively Population II stars. Thiseffort focuses on the Tip of the Red Giant Branch (TRGB) method, whosesystematics are entirely independent of the Population I Cepheid-baseddeterminations that have long served as calibrators for the SN Ia distancescale. We present deep Hubble Space Telescope imaging of the lowsurface-density and low line-of-sight reddening halos of two galaxies, NGC 1448and NGC 1316, each of which have been hosts to recent SN Ia events.Provisionally anchoring the TRGB zero-point to the geometric distance to theLarge Magellanic Cloud derived from detached eclipsing binaries, we measureextinction-corrected distance moduli of 31.23 +/-0.04 (stat) +/- 0.06 (sys) magfor NGC 1448 and 31.37 +/- 0.04 (stat) and +/- 0.06 (sys) mag for NGC 1316,respectively, giving metric distances of 17.7 +/- 0.3 (stat) +/- 0.5 (sys) Mpc,and 18.8 +/- 0.3 (stat) +/- 0.5 (sys) Mpc. We find agreement between our resultand the available Cepheid distance for NGC 1448; for NGC 1316, where there arerelatively few published distances based on direct measurements, we find thatour result is consistent with the published SN Ia distances whose absolutescales are set from other locally-determined methods such as Cepheids. For NGC1448 and NGC 1316, our distances are some of the most precise (andsystematically accurate) measurements with errors at 1.7 (2.8) % and 1.6 (2.7)% levels, respectively.

The Carnegie-Chicago Hubble Program. V. The Distances to NGC 1448 and NGC 1316 via the Tip of the Red Giant Branch