J-band Red Giant Branch Tip Magnitudes for the Distance Indicator

TL;DR

This study investigates the use of J-band magnitudes of the red giant branch tip as a distance indicator, finding it consistent with I-band measurements across various ages and metallicities, especially for old stellar populations.

Contribution

It introduces J-band RGB tip magnitudes as a reliable alternative to I-band methods for distance measurement in nearby galaxies.

Findings

J-band RGB tip magnitudes are consistent with I-band measurements.

J-band magnitudes remain stable within 0.005 mag for old populations.

The method is effective across a wide range of metallicities.

Abstract

The tip of the red giant branch is one of the widely used distance measurement methods for the relatively nearby galaxies where the bright individual stars are resolved. Most of the earlier works have used the Photometry in the I-band such as HST ACS/WFC F814W or F850LP for the RGB tip method. Here we look into the RGB tip magnitudes in J-band such as HST WFC3/IR F110W and JWST NIRCam/WF F115W for a wide range of age and metallicity. We find that the J-band (HST WFC3/IR F110W and JWST NIRCam/WF F115W) RGB tip magnitudes do not significantly change compared to that of the I-band (HST ACS/WFC F814W, F850LP) for a wide range of metallicity at given age. Moreover, HST WFC3/IR F110W RGB tip magnitudes stay constant within 0.005 magnitudes for stellar populations with old ages (age > 5 Gyr) at given metallicity.