Astrophysical Distance Scale II. Application of the JAGB Method: A
  Nearby Galaxy Sample
  We apply the near-infrared J-region Asymptotic Giant Branch (JAGB) method,
recently introduced by Madore \& Freedman (2020), to measure the distances to
14 nearby galaxies out to 4 Mpc. We use the geometric detached eclipsing binary
(DEB) distances to the LMC and SMC as independent zero-point calibrators. We
find excellent agreement with previously published distances based on the Tip
of the Red Giant Branch (TRGB): the JAGB distance determinations (including the
LMC and SMC) agree in the mean to within Delta(JAGB-TRGB) = +0.025 +/- 0.013
mag, just over 1%, where the TRGB I-band zero point is M_I = ~-4.05 mag. With
further development and testing, the JAGB method has the potential to provide
an independent calibration of Type Ia supernovae, especially with JWST. The
JAGB stars (with M_J = -6.20 mag) can be detected farther than the fainter TRGB
stars, allowing greater numbers of calibrating galaxies for the determination
of Ho. Along with the TRGB and Cepheids, JAGB stars are amenable to theoretical
understanding and further refined empirical calibration. A preliminary test
shows little dependence, if any, of the JAGB magnitude with metallicity of the
parent galaxy. These early results suggest that the JAGB method has
considerable promise for providing high-precision distances to galaxies in the
local universe that are independent of distances derived from the Leavitt Law
and/or the TRGB method; and it has numerous and demonstrable advantages over
the possible use of Mira variables.
