Near-infrared line-strengths in elliptical galaxies: evidence for initial mass function variations?

By A. Cenarro, J. Gorgas, A. Vazdekis, N. Cardiel, R. G. D. U. A. D. Madrid, Spain, Instituto de Astrof'isica de Canarias, Calar Alto Observatory, Caha, U. Nottingham and 1 more. 2002

143 citations recorded by the source corpus.

We present new relations between recently defined line-strength indices in the near-infrared (CaT*, CaT, PaT, MgI and sTiO) and central velocity dispersion (sigma(0) ) for a sample of 35 early-type galaxies, showing evidence for significant anti-correlations between Ca ii triplet indices (CaT* and CaT) and log sigma(0). These relations are interpreted in the light of our recent evolutionary synthesis model predictions, suggesting the existence of important Ca underabundances with respect to Fe and/or an increase of the dwarf to giant stars ratio along the mass sequence of elliptical galaxies.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/38292cf0ba164a471da1f275c90b31086348c112

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Citations in the corpus

MIUSCAT: extended MILES spectral coverage – I. Stellar population synthesis models (2012, background): “An index-index diagram, which includes this index and the CaII triplet at ∼8600 Å, has been proposed in Cenarro et al. (2003) to diagnose the IMF slope.”
THE STELLAR INITIAL MASS FUNCTION IN EARLY-TYPE GALAXIES FROM ABSORPTION LINE SPECTROSCOPY. II. RESULTS (2012, unknown): “Thanks largely to the increased quality of the stellar interior and atmospheric models and data in the intervening years, this technique is now capable of providing powerful constraints on the IMF (e.g., Cenarro et al. 2003).”
SPIDER VIII - constraints on the stellar initial mass function of early-type galaxies from a variety of spectral features (2013, background): “Some of the most discriminant features include the Na I doublet feature at λλ8183, 8195 Å (Faber & French 1980; Schiavon et al. 1997b, hereafter NaI8200), the Wing-Ford FeH band (Wing & Ford 1969; Schiavon et al. 1997a) at 9, 900 Å, prominent in the atmospheres of low-mass dwarves, as well as the ”
The ATLAS3D project – XX. Mass–size and mass–σ distributions of early-type galaxies: bulge fraction drives kinematics, mass-to-light ratio, molecular gas fraction and stellar initial mass function (2012, methodology): “…Spinrad & Taylor 1971), only the availability of reliable stellar population models has made the approach sufficiently accurate for IMF studies (Schiavon, Barbuy & Bruzual 2000; Cenarro et al. 2003). van Dokkum & Conroy (2010) analysed the IMF of eight massive ellipticals, from stacked spectra.”
The stellar IMF in early-type galaxies from a non-degenerate set of optical line indices (2013, background): “…1994) and to study possible correlation of IMF slope and α−enhancement variation with galaxy masses (Spinrad 1962; Spinrad & Taylor 1971; Cohen 1978; Frogel et al. 1978, 1980; Faber & French 1980; Carter et al. 1986; Hardy & Couture 1988; Couture & Hardy 1993; Worthey 1994; Cenarro et al. 2003).”
Evolutionary stellar population synthesis with MILES – II. Scaled-solar and α-enhanced models (2015, background): “…magnesium, there are exceptions to the rule such as calcium, which nearly tracks Fe (e.g. Vazdekis et al. 1997; Worthey 1998; Saglia et al. 2002; Cenarro et al. 2003; Falcón-Barroso et al. 2003b, Thomas, Maraston & Bender 2003b; Yamada et al. 2006; Worthey, Ingermann & Serven 2011; Conroy &…”
A CATALOG OF BULGE, DISK, AND TOTAL STELLAR MASS ESTIMATES FOR THE SLOAN DIGITAL SKY SURVEY (2013, background): “…IMF locally (Kroupa 2001), over the past several years there has been mounting evidence for systematic variation of the stellar IMF as a function of galaxy properties (e.g., Cenarro et al. 2003; Hoversten & Glazebrook 2008; van Dokkum & Conroy 2010; Gunawardhana et al. 2011; Dutton et al. 2012).”
Radial variations in the stellar initial mass function of early-type galaxies (2014, background): “…of the IMF is driven by an increase of the fraction of dwarf-to-giant stars, i.e. a change towards steeper IMF slopes with higher velocity dispersion (Cenarro et al. 2003; Falcón-Barroso et al. 2003; Cappellari et al. 2012; Ferreras et al. 2013; La Barbera et al. 2013, hereafter LB13).”
COUNTING LOW-MASS STARS IN INTEGRATED LIGHT (2011, methodology): “More recently, Cenarro et al. (2003) concluded that the IMF varies with velocity dispersion and [Fe/H] based on analysis of the CaII triplet, TiO, and MgI lines.”
The stellar and sub-stellar IMF of simple and composite populations (2011, background): “By studying various integrated gravity-sensitive features in luminous E galaxies, Cenarro et al. (2003) and van Dokkum & Conroy (2010) on the other hand find evidence for a very bottom-heavy IMF.”
EARLY-TYPE GALAXY ARCHEOLOGY: AGES, ABUNDANCE RATIOS, AND EFFECTIVE TEMPERATURES FROM FULL-SPECTRUM FITTING (2013, result): “Mg appears to track O closely, with a slight preference for [Mg/O]< 0.0 at high σ. Ca tracks Fe closely over the full sample, in agreement with previous work (Saglia et al. 2002; Cenarro et al. 2003; Thomas et al. 2003a; Graves et al. 2007; Schiavon 2007; Smith et al. 2009; Johansson et al. 2012).”
Systematic variation of the stellar initial mass function with velocity dispersion in early-type galaxies (2012, background): “More recently, Cenarro et al. (2003) proposed a relation towards an excess of lowmass stars in massive galaxies, from a study of the CaII triple region at∼8500Å .”
Empirical calibration of the near-infrared Ca II triplet — IV. The stellar population synthesis models (2003, unknown): “More details can be found in Cenarro et al. (2003).”