The Araucaria Project. Distances to Nine Galaxies Based on a Statistical Analysis of their Carbon Stars (JAGB Method)

TL;DR

This paper calibrates the JAGB method using infrared data to measure galaxy distances via carbon stars, achieving results consistent with Cepheid-based distances and other independent measures.

Contribution

It provides an independent calibration of the JAGB method and validates its accuracy against established distance indicators.

Findings

JAGB method yields distances consistent with Cepheid measurements.

Mean difference between methods is only 0.01 mag.

Distance to SMC agrees with eclipsing binary measurements.

Abstract

Our work presents an independent calibration of the J-region Asymptotic Giant Branch (JAGB) method using Infrared Survey Facility (IRSF) photometric data and a custom luminosity function profile to determine JAGB mean magnitudes for nine galaxies. We determine a mean absolute magnitude of carbon stars of $M_{LMC}=-6.212 \pm 0.010$ (stat.) $\pm 0.030$ (syst.) mag. We then use near-infrared photometry of a number of nearby galaxies, originally obtained by our group to determine their distances from Cepheids using the Leavitt law, in order to independently determine their distances with the JAGB method. We compare the JAGB distances obtained in this work with the Cepheid distances resulting from the same photometry and find very good agreement between the results from the two methods. The mean difference is 0.01 mag with an rms scatter of 0.06 mag after taking into account seven out of the eight analyzed galaxies that had their distances determined using Cepheids. The very accurate distance to the Small Magellanic Cloud (SMC) based on detached eclipsing binaries (Graczyk et al. 2020) is also in very good agreement with the distance obtained from carbon stars.