Globular clusters of NGC 3115 in the near-infrared: Demonstrating the correctness of two opposing scenarios

From National Research Council Canada

DOI	Resolve DOI: https://doi.org/10.1051/0004-6361/201323272
Author	Search for: Cantiello, M.; Search for: Blakeslee, J.P.¹; Search for: Raimondo, G.; Search for: Chies-Santos, A.L.; Search for: Jennings, Z.G.; Search for: Norris, M.A.; Search for: Kuntschner, H.
Affiliation	National Research Council of Canada. National Science Infrastructure
Format	Text, Article
Subject	Astrophysics; Galaxies; Infrared devices; Bimodal distribution; Color distribution; Galaxies: elliptical and lenticular , CD; Galaxies: individuals; Galaxies: star clusters: generals; Globular clusters; Metallicities; Spectroscopic data; Color
Abstract	We combined new near-infrared VLT/HAWK-I data of the globular clusters (GCs) in the isolated edge-on S0 galaxy NGC 3115 with optical and spectroscopic ones taken from the literature, with the aim of analyzing the multiband GC color distributions. A recent study from the SLUGGS survey has shown that the GCs in this galaxy follow a bimodal distribution of Ca II triplet indices. Thus, NGC 3115 presents a critical example of a GC system with multiple, distinct, metallicity subpopulations, and this may argue against the " projection" scenario, which posits that the ubiquitous color bimodality mainly results from nonlinearities in the color-metallicity relations. Using optical, NIR, and spectroscopic data, we found strong and consistent evidence of index bimodality, which independently confirms the metallicity bimodality in NGC 3115 GCs. At the same time, we also found evidence for some color-color nonlinearity. Taken in the broader context of previous studies, the multicolor consistency of the GC bimodality in NGC 3115 suggests that in cases where GC systems exhibit clear differences between their optical and optical-NIR color distributions (as in some giant ellipticals), the apparent inconsistencies most likely result from nonlinearities in the color-metallicity relations. © ESO, 2014.
Publication date	2014
In	Astronomy and Astrophysics 564, L3 (2014).
Language	English
Peer reviewed	Yes
NRC publication	This is a non-NRC publication "Non-NRC publications" are publications authored by NRC employees prior to their employment by NRC.
NPARC number	21272314
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Record identifier	a52ac9de-4d43-4391-8719-4efe0928c560
Record created	2014-07-28
Record modified	2020-04-22

Date modified:: 2024-04-19