Beccari, G, Bellazzini, M, Lardo, C, Bragaglia, A, Carretta, E, Dalessandro, E, Mucciarelli, A and Pancino, E (2013) Evidence for multiple populations in the massive globular cluster NGC 2419 from deep uVI LBT photometry. Monthly Notices of the Royal Astronomical Society, 431 (2). pp. 1995-2005. ISSN 0035-8711
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Abstract
We present accurate wide-field uVI photometry of the remote and massive Galactic globular cluster NGC 2419, aimed at searching for the u-V color spread along the Red Giant Branch (RGB) that is generally interpreted as the photometric signature of the presence of multiple populations in globular clusters. Focusing on the RGB stars in the magnitude range 19.8<V<22.0, we find that (a) the u-V, u-I and the V-I spreads about the RGB ridge line are significantly larger than that expected from observational errors, accurately quantified by means of extensive artificial stars experiments, (b) the intrinsic color spread in u-V and u-I are larger than in V-I, (c) the stars lying to the blue of the RGB ridge line in u-V and u-I are significantly more concentrated toward the cluster center than those lying to the red of that line. All the above observational facts can be interpreted in a scenario where a sizable fraction of cluster stars belong to a second generation heavily enriched in Helium. Finally we find that bright RGB stars (17.5<V<19.0) having [Mg/Fe]<0.0 lie preferentially on the red side of the cluster RGB, while those having [Mg/Fe]>0.0 lie preferentially on the blue side.
Item Type: | Article |
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Additional Information: | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society] ©: 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Uncontrolled Keywords: | 0201 Astronomical And Space Sciences |
Subjects: | Q Science > QB Astronomy Q Science > QC Physics |
Divisions: | Astrophysics Research Institute |
Publisher: | Oxford University Press |
Related URLs: | |
Date Deposited: | 20 Jan 2017 09:30 |
Last Modified: | 26 Apr 2022 14:12 |
DOI or ID number: | 10.1093/mnras/stt316 |
URI: | https://researchonline.ljmu.ac.uk/id/eprint/5321 |
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