Asymptotic Giant Branch Variables as Extragalactic Distance Indicators

TL;DR

This paper explores the potential of asymptotic giant branch variables as alternative extragalactic distance indicators, especially in infrared observations and obscured regions, with new calibration data and future prospects.

Contribution

It introduces new calibration data and discusses future prospects for using AGB variables as reliable distance indicators in extragalactic astronomy.

Findings

AGB variables can rival Cepheids in distance measurement accuracy

Infrared observations enhance the utility of AGB variables

Future Gaia calibration will improve AGB-based distance estimates

Abstract

Large-amplitude asymptotic giant branch variables potentially rival Cepheid variables as fundamental calibrators of the distance scale, particularly if observations are made in the infrared, or where there is substantial interstellar obscuration. They are particularly useful for probing somewhat older populations, such as those found in dwarf spheroidal galaxies, elliptical galaxies or in the halos of spirals. Calibration data from the Galaxy and new observations of various Local Group galaxies are described and the outlook for the future, with a calibration from Gaia and observations from the next generation of infrared telescopes, is discussed.