Astrophysical Distance Scale IV. Preliminary Zero-Point Calibration of the JAGB Method in the HST/WFC3-IR Broad J-Band (F110W) Filter

TL;DR

This paper calibrates the JAGB method for distance measurement using HST/WFC3-IR data, achieving a precise zero-point calibration with a 4% scatter, based on a large sample of stars in nearby galaxies.

Contribution

It provides the first absolute zero-point calibration of the JAGB method in the F110W filter using TRGB distances, with a detailed analysis of scatter and uncertainties.

Findings

JAGB stars have an absolute magnitude of -5.77 mag in F110W.

The method achieves a 4% distance accuracy with a scatter of 0.081 mag.

The calibration supports the JAGB method as a reliable distance indicator.

Abstract

We present an absolute calibration of the J-region Asymptotic Giant Branch (JAGB) method using published photometry of resolved stars in 20 nearby galaxies observed with HST using the WFC3-IR camera and the F110W (Broad J-Band) filter. True distance moduli for each of the galaxies are based on the Tip of the Red Giant Branch (TRGB) method as uniformly determined by Dalcanton et al. (2012). From a composite color-magnitude diagram composed of over 6 million stars, leading to a sample of 453 JAGB stars in these galaxies, we find M_{F110W}{JAGB} = -5.77 +/- 0.02 mag(statistical error on the mean). The external scatter seen in a comparison of the individual TRGB and the JAGB moduli is +/-0.081 mag (or 4% in distance). Some of this scatter can be attributed to small-number statistics arising from the sparse JAGB populations found in the generally low-luminosity galaxies that comprise the particular sample studied here. However, if this inter-method scatter is shared equitably between the JAGB and TRGB methods that implies that each are good to +/-0.06 mag, or better than 3% in distance.