Refining open cluster parameters with Gaia XP metallicities

Fuente: arXiv
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Main Authors: Nizovkina, M., Larsen, S. S., Brown, A. G. A., Helmi, A.
Format: Preprint
Published: 2025
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author Nizovkina, M.
Larsen, S. S.
Brown, A. G. A.
Helmi, A.
author_facet Nizovkina, M.
Larsen, S. S.
Brown, A. G. A.
Helmi, A.
contents The precision of cluster parameter determination has significantly improved with the availability of homogeneous photometric Gaia data, however, challenges such as age-metallicity degeneracy and lack of spectroscopic observations remain. In this paper we investigate whether metallicities derived from low-resolution Gaia XP spectra can be effectively used to break degeneracies and improve the accuracy of OC parameter determinations. We analysed 20 OCs using isochrone fitting methods on Gaia DR3 photometry and metallicity estimates from several Gaia XP-based catalogues. We derived age, distance modulus, and extinction using the Approximate Bayesian Computation (ABC). We compared the parameter estimates to the values obtained in other works through isochrone fitting with spectroscopically constrained metallicities or through neural network techniques applied only to the photometry. We found the systematic difference between Gaia XP derived metallicities and those obtained from high-resolution spectroscopy to be 0.1-0.15 dex. We found a systematic age difference of <0.03 +- 0.13 dex compared to isochrone fitting using high-resolution spectroscopy, and <0.08 +- 0.21 dex compared to neural network-based methods, and a median individual error of ~0.065 dex. Despite their low resolution, Gaia XP metallicities effectively constrain parameters of clusters lacking a well-populated RGB. When used with stringent quality cuts and incorporated as priors, they allow to determine ages comparable in precision to those based on high-resolution spectroscopy and more precise than photometry-only neural network methods. These results highlight the potential of Gaia data for accurate cluster parameter analysis and detailed Galactic studies without relying on traditional spectroscopy.
format Preprint
id arxiv_https___arxiv_org_abs_2510_10385
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Refining open cluster parameters with Gaia XP metallicities
Nizovkina, M.
Larsen, S. S.
Brown, A. G. A.
Helmi, A.
Astrophysics of Galaxies
The precision of cluster parameter determination has significantly improved with the availability of homogeneous photometric Gaia data, however, challenges such as age-metallicity degeneracy and lack of spectroscopic observations remain. In this paper we investigate whether metallicities derived from low-resolution Gaia XP spectra can be effectively used to break degeneracies and improve the accuracy of OC parameter determinations. We analysed 20 OCs using isochrone fitting methods on Gaia DR3 photometry and metallicity estimates from several Gaia XP-based catalogues. We derived age, distance modulus, and extinction using the Approximate Bayesian Computation (ABC). We compared the parameter estimates to the values obtained in other works through isochrone fitting with spectroscopically constrained metallicities or through neural network techniques applied only to the photometry. We found the systematic difference between Gaia XP derived metallicities and those obtained from high-resolution spectroscopy to be 0.1-0.15 dex. We found a systematic age difference of <0.03 +- 0.13 dex compared to isochrone fitting using high-resolution spectroscopy, and <0.08 +- 0.21 dex compared to neural network-based methods, and a median individual error of ~0.065 dex. Despite their low resolution, Gaia XP metallicities effectively constrain parameters of clusters lacking a well-populated RGB. When used with stringent quality cuts and incorporated as priors, they allow to determine ages comparable in precision to those based on high-resolution spectroscopy and more precise than photometry-only neural network methods. These results highlight the potential of Gaia data for accurate cluster parameter analysis and detailed Galactic studies without relying on traditional spectroscopy.
title Refining open cluster parameters with Gaia XP metallicities
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2510.10385