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Auteurs principaux: Chriss, Abigail R., Worthey, Guy
Format: Preprint
Publié: 2024
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Accès en ligne:https://arxiv.org/abs/2402.18538
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author Chriss, Abigail R.
Worthey, Guy
author_facet Chriss, Abigail R.
Worthey, Guy
contents In this study, we extend the dust-independent Hatzidimitriou (1991) relation between cluster age and $d_{B-R}$ color difference between the red giant branch (RGB) and red clump to younger cluster ages. We perform membership analysis on fourteen galactic open clusters using Gaia DR3 astrometry, then compute the difference in color of the RGB and red clump $d_{B-R}$ using Gaia photometry. We also compute $d_{B-R}$ for five fields surrounding Small Magellanic Cloud (SMC) clusters. We find that the trend derived from older clusters does not extrapolate to younger ages and becomes double-valued. We confirm that $d_{B-R}$ is independent of metallicity. Current stellar evolutionary isochrones do not quantitatively reproduce the trend and furthermore predict an increased color gap with a decrease in metallicity that is not echoed in the data. Integrated light models based on current isochrones exaggerate the color change over the $-0.5 <$ [Fe/H] $< 0$ interval at the few-percent level.
format Preprint
id arxiv_https___arxiv_org_abs_2402_18538
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On the Age Calibration of Open Clusters using Red Clump Stars
Chriss, Abigail R.
Worthey, Guy
Astrophysics of Galaxies
In this study, we extend the dust-independent Hatzidimitriou (1991) relation between cluster age and $d_{B-R}$ color difference between the red giant branch (RGB) and red clump to younger cluster ages. We perform membership analysis on fourteen galactic open clusters using Gaia DR3 astrometry, then compute the difference in color of the RGB and red clump $d_{B-R}$ using Gaia photometry. We also compute $d_{B-R}$ for five fields surrounding Small Magellanic Cloud (SMC) clusters. We find that the trend derived from older clusters does not extrapolate to younger ages and becomes double-valued. We confirm that $d_{B-R}$ is independent of metallicity. Current stellar evolutionary isochrones do not quantitatively reproduce the trend and furthermore predict an increased color gap with a decrease in metallicity that is not echoed in the data. Integrated light models based on current isochrones exaggerate the color change over the $-0.5 <$ [Fe/H] $< 0$ interval at the few-percent level.
title On the Age Calibration of Open Clusters using Red Clump Stars
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2402.18538