The absorption-line strengths of elliptical and S0 galaxies

Burstein, David

doi:10.1086/157266

Cited by 25 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies showed that (Mg 2 ) 0 correlate with the velocity dispersion σ 0 at the galaxy center Burstein et al 1988;Bender, Burstein, & Faber 1993). A similar relation holds for (Mg 2 ) 0 and total absolute magnitudes M B (Faber 1973;Burstein 1979;Terlevich et al 1981;Dressler 1984). If, admittedly a big if, one can assume that elliptical galaxies are old, one can convert Mg 2 into the metallicity Z either empirically (Burstein et al 1984;Faber et al 1985) or theoretically with a help of population synthesis models (Mould 1978;Peletier 1989;Buzzoni, Gariboldi, & Mantegazza 1992;Barbuy 1994;Worthey 1994;Casuso et al 1996;Bressan, Chiosi, & Tantalo 1996;Kodama & Arimoto 1997).…”

Section: Introductionsupporting

confidence: 56%

Gradients of Absorption‐Line Strengths in Elliptical Galaxies

Kobayashi

Arimoto

1999

ApJ

167

200

View full text Add to dashboard Cite

We have re-studied line-strength gradients of 80 elliptical galaxies. Typical metallicity gradients of elliptical galaxies are ∆[Fe/H]/∆ log r ≃ −0.3 which is flatter than the gradients predicted by monolithic collapse simulations. The metallicity gradients do not correlate with any physical properties of galaxies, including central and mean metallicities, central velocity dispersions σ 0 , absolute B-magnitudes M B , absolute effective radii R e , and dynamical masses of galaxies. By using the metallicity gradients, we have calculated mean stellar metallicities for individual ellipticals. Typical mean stellar metallicities are [Fe/H] ≃ −0.3, and range from [Fe/H] ≃ −0.8 to +0.3, which is contrary to what Gonzalez & Gorgas (1996) claimed; the mean metallicities of ellipticals are not universal. The mean metallicities correlate well with σ 0 and dynamical masses, though relations for M B and R e include significant scatters. We find fundamental planes defined by surface brightnesses SB e , [Fe/H] , and R e (or M B ), and the scatters of which are much smaller than those of the [Fe/H] -R e (or M B ) relations. The [Fe/H] -log σ 0 relation is nearly in parallel to the [Fe/H] 0 -log σ 0 relation but systematically lower by 0.3 dex; thus the mean metallicities are about a half of the central values. The metallicity-mass relation, or equivalently, the color-magnitude relation of ellipticals holds not only for the central part but also for the whole part of galaxies. Assuming that Mg 2 and Fe 1 give [Mg/H] and [Fe/H], respectively, we find [Mg/Fe] ≃ +0.2 in most of elliptical galaxies. [Mg/Fe] shows no correlation with galaxy mass tracers such as σ 0 , in contrast to what was claimed for the central [Mg/Fe].This can be most naturally explained if the star formation had stopped in elliptical galaxies before the bulk of Type Ia supernovae began to explode. Elliptical galaxies can have significantly different metallicity gradients and [Fe/H] even if they have the same galaxy mass. This may result from galaxy mergers, but no evidence is found from presently available data to support the same origin for metallicity gradients, the scatters around metallicity-mass relation, and dynamical disturbances. This may suggest that the scatters have their origin at the formation epoch of galaxies.

show abstract

Section: Introductionsupporting

confidence: 56%

Gradients of Absorption‐Line Strengths in Elliptical Galaxies

Kobayashi

Arimoto

1999

ApJ

167

200

View full text Add to dashboard Cite

show abstract

“…Davies et al 1993). To transform the linestrength gradients into metallicity gradients, each of these studies used the Mould (1978), Burstein (1979), and Faber et al (1985) calibrations. In all these cases, they assumed a null age gradient.…”

Section: Metallicity Gradientsmentioning

confidence: 99%

Stellar populations of early-type galaxies in different environments

Sánchez‐Blázquez

Gorgas

Cardiel

2006

A&A

101

View full text Add to dashboard Cite

Aims. This is the third paper of a series devoted to the study of the stellar content of early-type galaxies. The goal of the series is to set constraints on the evolutionary status of these objects. Methods. We present line-strength gradients for 22 spectral indices measured in a sample of 82 early-type galaxies in different environments, including the high-density cores of the Coma cluster, the Virgo cluster, poor groups, and isolated field galaxies. Using new evolutionary population synthesis models, we derive age and metallicity gradients, and compare the mean values with the predictions of different galaxy formation models. We explore the behaviour of individual chemical species by deriving the metallicity gradient with different indicators. Results. We find that the strength of the metallicity gradient inferred from stellar population models depends on the specific Lick index employed. In particular, metallicity gradients obtained with CN 2 and C4668 combined with Hβ are steeper than those measured using Ca4227 or Fe4383. The correlation of the metallicity gradients with other parameters also depends on the specific index employed. If the metallicity gradient is obtained using CN 2 and Mgb, then it correlates with the central age of the galaxies. On the contrary, if Fe4383 or Ca4227 is used, the metallicity gradient correlates with the velocity dispersion gradient. Conclusions. This may suggest that several mechanisms have helped to set the age and metallicity gradients in early-type galaxies. While we do not find any correlation between the metallicity gradient and the central velocity dispersion for galaxies in low-density environments, we find a marginal correlation between the metallicity gradient and the mass for galaxies in the centre of the Coma cluster. We also find a trend for which galaxies in denser environments show a steeper metallicity gradient than galaxies in less dense environments. We interpret these results in light of the different mechanisms proposed to explain the observed changes between galaxies as a function of environment.

show abstract

“…The calibration of M g 2 against [Fe/H] normally used (Burstein, 1979), based on globular clusters observations and stellar models with solar relative abundances, is expected to fail in reproducing the relation existing in ellipticals. Furthermore, the observed spectral indices are produced from the contribution of all stars, averaged with their luminosities.…”

Section: Chemical Evolutionmentioning

confidence: 99%

Evolution of elliptical galaxies. I - The multiphase model

Ferrini¹,

Poggianti²

1993

ApJ

View full text Add to dashboard Cite

We present a complex model for the evolution of elliptical galaxies in the general framework of the multiphase models for galactic evolution.The elliptical is subdivided into an internal and an external region and their individual but joined evolution is computed in detail.Diffuse gas, molecular clouds, stars and remnants are taken into account. The Star Formation Rate is therefore assumed to be a two-step process: gas clouds form out of diffuse gas and then stars form out of gas clouds. Cloud-cloud collisions and stimulated processes are considered as the main causes of star formation. The occurrence of winds driven by Supernovae is taken into account, and the evolution of the system is considered also after the first wind, allowing for further star formation from the restored gas.The evolution of the abundances of 15 elements or isotopes (H, D, 3 He, 4 He, 12 C, 13 C, 14 N, 16 O, 20 Ne, 24 Mg, 28 Si, 32 S, 40 Ca, 56 Fe, and neutron-rich isotopes synthetized from 12 C, 13 C, 14 N and 16 O) is followed with detailed stellar nucleosynthesis as well as stellar lifetimes are taken into account as a consequence of relaxing the instantaneous recycling approximation. A new IMF, constant in space and time, has also been adopted.The gas removal due to the Supernovae explosions depends on the galactic mass and the presence of dark matter; the subsequent wind episodes are crucial to the intergalactic gas enrichment. Good agreement is obtained for current SNs rates, Star Formation Rate and gas masses when compared to the available data.

show abstract

The absorption-line strengths of elliptical and S0 galaxies

Cited by 25 publications

References 0 publications

Gradients of Absorption‐Line Strengths in Elliptical Galaxies

Gradients of Absorption‐Line Strengths in Elliptical Galaxies

Stellar populations of early-type galaxies in different environments

Evolution of elliptical galaxies. I - The multiphase model

Contact Info

Product

Resources

About