The Tip of the Red Giant Branch Distances to Type Ia Supernova Host
  Galaxies. V. NGC 3021, NGC 3370, and NGC 1309 and the value of the Hubble
  Constant
  We present final results of a program for the determination of the Hubble
constant based on the calibration of the Type Ia supernovae (SNe Ia) using the
Tip of the Red Giant Branch (TRGB). We report TRGB distances to three SN Ia
host galaxies, NGC 3021, NGC 3370, and NGC 1309. We obtain F555W and F814W
photometry of resolved stars from the archival Hubble Space Telescope data.
Luminosity functions of red giant stars in the outer regions of these galaxies
show the TRGB to be at I ~ QT = 28.2 ~ 28.5 mag. From these TRGB magnitudes and
the revised TRGB calibration based on two distance anchors (NGC 4258 and the
LMC) in Jang&Lee 2017, we derive the distances: (m-M)0 = 32.178 +- 0.033 for
NGC 3021, 32.253 +- 0.041 for NGC 3370, and 32.471 +- 0.040 for NGC 1309. We
update our previous results on the TRGB distances to five SN Ia host galaxies
using the revised TRGB calibration. By combining the TRGB distance estimates to
SN Ia host galaxies in this study with the SN Ia calibration provided by Riess
et al. 2011, we obtain a value of the Hubble constant: H0 = 71.66 +- 1.80
(random) +- 1.88 (systematic) km/s/Mpc (a 3.6% uncertainty including
systematics) from all eight SNe, and H0 = 73.72 +- 2.03 +- 1.94 km/s/Mpc (a
3.8% uncertainty) from six low-reddened SNe. We present our best estimate, H0 =
71.17 +- 1.66 +- 1.87 km/s/Mpc (a 3.5% uncertainty) from six low-reddened SNe
with the recent SN Ia calibration in Riess et al. 2016. This value is between
those from the Cepheid calibrated SNe Ia and those from the Cosmic Microwave
Background (CMB) analysis, lowering the Hubble tension.
