Early-type galaxies in the Coma cluster: a new piece in the calcium puzzle

Abstract

We present measurements of the CaII triplet and the Ca4227 Lick-index for a sample of early-type galaxies in the Coma cluster, deriving, for the first time, their corresponding relationships with velocity dispersion. Compared with a similar subsample of ellipticals in the field, Coma galaxies with velocity dispersions in the range ~ 180-270 km/s exhibit significant differences in the strengths of the Ca features, suggesting an influence of the environment on the star formation histories of these galaxies. We argue that the main scenarios previously proposed to explain the relatively low CaII triplet of galaxies are not able by themselves to simultaneously reconcile the strengths of the two Ca indices in both environments.

arXiv comment6 pages including 2 figures. Accepted for publication in ApJL. For associated data tables see http://www.ucm.es/info/Astrof/ellipt/CATRIPLET.html

References in corpus (19)

• Stellar population models of Lick indices with variable element abundance ratios
• Old Stellar Populations. VI. Absorption-Line Spectra of Galaxy Nuclei and Globular Clusters
• Empirical calibration of the near-IR Ca II triplet - I. The stellar library and index definition
• Galactic Globular Cluster Metallicity Scale from the Calcium Triplet. II. Rankings, Comparisons and Puzzles
• E and S0 galaxies in the central part of the Coma cluster: Ages, metal abundances and dark matter
• A new chemo-evolutionary population synthesis model for early-type galaxies. II: Observations and Results
• Empirical calibration of the near-IR CaII triplet - IV. The stellar population synthesis models
• A comparison of stellar populations in galaxy populations across a wide range of Hubble types
• Near-IR line-strengths in elliptical galaxies: evidence for IMF variations?
• Chemical Enrichment and the Origin of the Colour-Magnitude Relation of Elliptical Galaxies in a Hierarchical Merger Model
• Early-type galaxies in low-density environments
• Empirical calibration of the near-IR Ca II triplet - III. Fitting functions
• The puzzlingly small CaII triplet absorption in elliptical galaxies
• Empirical calibration of the near-IR Ca II triplet - II. The stellar atmospheric parameters
• On the Origin of the Colour-Magnitude Relation in the Virgo Cluster
• The puzzlingly large Ca II triplet absorption in dwarf elliptical galaxies
• Differences in carbon and nitrogen abundances between field and cluster early-type galaxies
• Population Synthesis in the Blue I. Synthesis of the Integrated Spectrum of 47 Tucanae from its Color-Magnitude Diagram
• The near-IR Ca II triplet - sigma relation for bulges of spiral galaxies

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