oMEGACat V: Helium Enrichment in $ω$ Centauri as a Function of Metallicity

Fuente: arXiv
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Autores principales: Clontz, C., Seth, A. C., Wang, Z., Souza, S. O., Häberle, M., Nitschai, M. S., Neumayer, N., Latour, M., Milone, A. P., Feldmeier-Krause, A., Kacharov, N., Libralato, M., Bellini, A., van de Ven, G., Alfaro-Cuello, M.
Formato: Preprint
Publicado: 2024
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author Clontz, C.
Seth, A. C.
Wang, Z.
Souza, S. O.
Häberle, M.
Nitschai, M. S.
Neumayer, N.
Latour, M.
Milone, A. P.
Feldmeier-Krause, A.
Kacharov, N.
Libralato, M.
Bellini, A.
van de Ven, G.
Alfaro-Cuello, M.
author_facet Clontz, C.
Seth, A. C.
Wang, Z.
Souza, S. O.
Häberle, M.
Nitschai, M. S.
Neumayer, N.
Latour, M.
Milone, A. P.
Feldmeier-Krause, A.
Kacharov, N.
Libralato, M.
Bellini, A.
van de Ven, G.
Alfaro-Cuello, M.
contents Constraining the helium enhancement in stars is critical for understanding the formation mechanisms of multiple populations in star clusters. However, measuring helium variations for many stars within a cluster remains observationally challenging. We use Hubble Space Telescope photometry combined with MUSE spectroscopic data for over 7,200 red-giant branch stars in \omc\ to measure helium differences between distinct groups of stars as a function of metallicity separating the impact of helium enhancements from other abundance variations on the pseudo-color (chromosome) diagrams. Our results show that stars at all metallicities have subpopulations with significant helium enhancement ($ΔY_{min} \gtrsim$ 0.11). We find a rapid increase in helium enhancement from low metallicities ($\rm{[Fe/H] \simeq -2.05}$ to $\rm{[Fe/H] \simeq -1.92})$, with this enhancement leveling out at \deltay\ $= 0.154$ at higher metallicities. The fraction of helium-enhanced stars steadily increases with metallicity ranging from 10\% at $\rm{[Fe/H] \simeq -2.04}$ to over $90\%$ at $\rm{[Fe/H] \simeq -1.04}$. This study is the first to examine helium enhancement across the full range of metallicities in \omc{}, providing new insight into its formation history and additional constraints on enrichment mechanisms.
format Preprint
id arxiv_https___arxiv_org_abs_2412_09783
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle oMEGACat V: Helium Enrichment in $ω$ Centauri as a Function of Metallicity
Clontz, C.
Seth, A. C.
Wang, Z.
Souza, S. O.
Häberle, M.
Nitschai, M. S.
Neumayer, N.
Latour, M.
Milone, A. P.
Feldmeier-Krause, A.
Kacharov, N.
Libralato, M.
Bellini, A.
van de Ven, G.
Alfaro-Cuello, M.
Astrophysics of Galaxies
Solar and Stellar Astrophysics
Constraining the helium enhancement in stars is critical for understanding the formation mechanisms of multiple populations in star clusters. However, measuring helium variations for many stars within a cluster remains observationally challenging. We use Hubble Space Telescope photometry combined with MUSE spectroscopic data for over 7,200 red-giant branch stars in \omc\ to measure helium differences between distinct groups of stars as a function of metallicity separating the impact of helium enhancements from other abundance variations on the pseudo-color (chromosome) diagrams. Our results show that stars at all metallicities have subpopulations with significant helium enhancement ($ΔY_{min} \gtrsim$ 0.11). We find a rapid increase in helium enhancement from low metallicities ($\rm{[Fe/H] \simeq -2.05}$ to $\rm{[Fe/H] \simeq -1.92})$, with this enhancement leveling out at \deltay\ $= 0.154$ at higher metallicities. The fraction of helium-enhanced stars steadily increases with metallicity ranging from 10\% at $\rm{[Fe/H] \simeq -2.04}$ to over $90\%$ at $\rm{[Fe/H] \simeq -1.04}$. This study is the first to examine helium enhancement across the full range of metallicities in \omc{}, providing new insight into its formation history and additional constraints on enrichment mechanisms.
title oMEGACat V: Helium Enrichment in $ω$ Centauri as a Function of Metallicity
topic Astrophysics of Galaxies
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2412.09783