Principal Investigator: Abigail Lee
PI Institution: University of Chicago
Investigators
(xml)
Title: Quantifying Systematics in the JAGB Method Distance Scale in M31
Cycle: 30
Abstract
JAGB stars, a subset of carbon-rich, thermally-pulsating AGB stars, have well-defined, low-dispersion absolute magnitudes in the near infrared, making them excellent standard candles. The JAGB star extragalactic distance indicator has been shown to be on par with the Cepheid and TRGB methods in both precision and accuracy, and therefore capable of acting as a powerful cross-check on SN Ia host galaxy distances. However, because the JAGB method is still relatively novel, it has not been as well tested as the Cepheid and TRGB distance indicators. We propose to leverage archival data from the Panchromatic Hubble Andromeda Treasury (PHAT) in M31 to quantify how the host galaxy star formation history, internal reddening, and metallicity may affect the JAGB method distance scale. The JAGB method has already been shown to be highly precise; understanding the systematics of even these small effects will further increase its precision. Once the potential systematics of the JAGB method have been thoroughly investigated, the JAGB method can be used to provide an independent local measurement of H0, and cross-check TRGB and Cepheid distances. As a bonus, this proposal will help provide observational constraints on the carbon star luminosity function in different stellar environments, directly guiding theoretical models of carbon star evolution which includes winds, dredge-ups, and hot-bottom burning.