The Carnegie-Chicago Hubble Program. IV. The Distances to NGC 4424, NGC
  4526, and NGC 4536 via the Tip of the Red Giant Branch
  The Carnegie-Chicago Hubble Program (CCHP) is undertaking a re-calibration of
the extragalactic distance scale, using Type Ia supernovae that are tied to Tip
of the Red Giant Branch (TRGB) distances to local galaxies. We present here
deep Hubble Space Telescope (HST) ACS/WFC imaging of the resolved stellar
populations in the metal-poor halos of the SN Ia host galaxies NGC 4424, NGC
4526, and NGC 4536. These three Virgo constellation galaxies are prime targets
for calibrating the extragalactic distance scale given their relative proximity
in the local Universe and their low line-of-sight reddenings. Anchoring the
TRGB zero-point to the geometric distance to the Large Magellanic Cloud via
detached eclipsing binaries, we measure extinction-corrected distance moduli of
31.00 +/- 0.03 (stat) +/- 0.06 (sys) mag, 30.98 +/- 0.03 (stat) +/- 0.06 (sys)
mag, and 30.99 +/- 0.03 (stat) +/- 0.06 (sys) mag for NGC 4424, NGC 4526, and
NGC 4536, respectively, or 15.8 +/- 0.2 (stat) +/- 0.4 (sys) Mpc, 15.7 +/- 0.2
(stat) +/- 0.4 (sys) Mpc, and 15.8 +/- 0.2 (stat) +/- 0.4 (sys) Mpc. For these
three galaxies, the distances are the first based on the TRGB, and for NGC 4424
and NGC 4526, they are the highest precision distances published to date, each
measured to 3%. Finally, we report good agreement between our TRGB distances
and the available Cepheid distances for NGC 4424 and NGC 4536, demonstrating
consistency between the distance scales currently derived from stars of
Population I and II.
