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Goudfrooij, Paul; Gorgas, J.; Jablonka, P.

doi:10.1023/a:1017015808447

Cited by 37 publications

(50 citation statements)

References 22 publications

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“…Using the SSP models from Worthey & Ottaviani (1997) and the Hβ index measured by Goudfrooij et al (1999), they quote an age of 11.8 Gyr for NGC 4374. The quoted ages for merger remnants like NGC 1316 and NGC 5018 (host to the Ia supernova 2002dj) are 3.4 Gyr and 1.5 Gyr, respectively.…”

Section: Discussionmentioning

confidence: 99%

The globular cluster system of NGC 4374

Gómez¹,

Richtler²

2004

A&A

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Abstract. We study the globular cluster system (GCS) of the giant elliptical NGC 4374 (M 84) in the Virgo cluster using B and R photometry. The colour distribution is bimodal with peaks at B − R = 1.11 and B − R = 1.36, fitting well to those found in other early-type galaxies. The radial profile of the cluster number density is flatter than the galaxy light. Using the luminosity function we derive a distance modulus of µ = 31.61 ± 0.2, which within the uncertainty agrees with the distance from surface brightness fluctuations. Blue and red clusters show similar radial concentrations and azimuthal distributions. The total number of clusters is N = 1775 ± 150, which together with our distance modulus leads to a specific frequency of S N = 1.6 ± 0.3. This value is surprisingly low for a giant elliptical, but resembles the case of merger remnants like NGC 1316, where the low specific frequency is probably caused by the luminosity contribution of an intermediate-age population. A further common property is the high rate of type Ia supernovae which also may indicate the existence of a younger population. However, unlike in the case of NGC 1316, one cannot find any further evidence that NGC 4374 indeed hosts younger populations. The low specific frequency would also fit to a S0 galaxy seen face-on.

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Section: Discussionmentioning

confidence: 99%

The globular cluster system of NGC 4374

Gómez¹,

Richtler²

2004

A&A

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“…Some authors (e.g. Thomas & Davies 2006;Goudfrooij et al 1999) have concluded that galaxies with morphological types from E to as late as Sbc have stellar population properties that are correlated to the central velocity dispersion (σ) and that, at a given σ, bulges and elliptical galaxies cannot be distinguished by their stellar populations, indicating very little influence of the disk on the evolution of the bulge. Recent work by MacArthur et al (2009) have derived the whole star formation histories for the bulges of a sample of eight galaxies, finding that the mass-weighted stellar ages of the bulges are old and that secular evolution effects therefore only contribute minimally to the total bulge mass.…”

Section: Introductionmentioning

confidence: 99%

Study of stellar populations in the bulges of barred galaxies

Pérez

Sánchez‐Blázquez

2011

A&A

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Aims. We wish to determine the influence of bars on the building of galaxy bulges through analysis of ages and metallicities derived from stellar absorption line-strength indices. Methods. Long-slit spectroscopy was obtained for a sample of 20 early-type barred galaxies. Line-strength indices were measured and used to derive age and metallicity gradients in the bulge region by comparing them with stellar population models. The same analysis was carried out with similar data for unbarred galaxies taken from the literature. Results. The bulges of barred galaxies seem to be more metal rich, at a given velocity dispersion (σ), than the bulges of unbarred galaxies, as measured by a few metallicity sensitive indices. There are indications that the ratio of relative abundance of alpha elements with respect to iron, [E/Fe], derived for the bulges of barred galaxies tend to lie above the values of the unbarred galaxies at a given σ. The metallicity gradients for the majority of the bulges are negative so less metal-rich towards the end of the bulge. The gradient values show a large scatter for galaxies with σ below 150 km s −1 . The age distribution is related to the presence of a bulge substructure, such as a nuclear ring or an inner disk. The metallicity of both the bulge and the bar are very well correlated, indicating a close link between the enrichment histories of both components. Conclusions. Bulges of barred early type galaxies might have experienced a different chemical enrichment than do the bulges of unbarred galaxies of the same morphological type, the same central velocity dispersion, and low inclination angles. The hinted stellar populations differences separating the bulges of barred and unbarred galaxies and the strong link between the metallicity of the bulge and the presence of a bar points to scenarios where they both form simultaneously in processes that lead to rapid and massive episodes of star formation, possibly linked to the bar formation. To confirm and generalise the results found here, it would be useful to extend the data set to a larger number of unbarred galaxies and a wider range of morphological types

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“…Assumed the metallicity (and hence ζ, τ , and ν), there is an almost-linear relation between the bulge mass (the mass of the disc follows from M disc,⊙ = 10 11 − M bulge,⊙ because all the intermediate types have the same total mass of 10 11 M⊙) and the luminosity. the central bulge of the Milky Way show that it mainly contains metal-rich stars (Frogel 1988(Frogel , 1999 and this seems to be quite common also among external galaxies (Jablonka, Arimoto & Martin 1996;Goudfrooij, Gorgas & Jablonka 1999;Davidge 2001). The exact average value of the bulge metallicity, however, has been subject to continuously revised, going from [Fe/H] ∼ +0.2 (Whitford & Rich 1983;Rich 1990;Geisler & Friel 1992)) to lower values, consistent with a standard or even slightly sub-solar metallicity (Tiede, Frogel & Terndrup 1995;Sadler, Rich & Terndrup 1996;Zoccali et al 2003;Origlia, Valenti & Rich 2005).…”

Section: Theoretical and Observational Colours Of Galaxiesmentioning

confidence: 99%

Modelling galaxy spectra in presence of interstellar dust – III. From nearby galaxies to the distant Universe

Cassarà¹,

Piovan

Chiosi

2015

Monthly Notices of the Royal Astronomical Society

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Improving upon the standard evolutionary population synthesis (EPS) technique, we present spectrophotometric models of galaxies whose morphology goes from spherical structures to discs, properly accounting for the effect of dust in the interstellar medium (ISM). These models enclose three main physical components: the diffuse ISM composed by gas and dust, the complexes of molecular clouds (MCs) where active star formation occur and the stars of any age and chemical composition. These models are based on robust evolutionary chemical models that provide the total amount of gas and stars present at any age and that are adjusted in order to match the gross properties of galaxies of different morphological type. We have employed the results for the properties of the ISM presented in Piovan, Tantalo & Chiosi (2006a) and the single stellar populations calculated by Cassarà et al. (2013) to derive the spectral energy distributions (SEDs) of galaxies going from pure bulge to discs passing through a number of composite systems with different combinations of the two components. The first part of the paper is devoted to recall the technical details of the method and the basic relations driving the interaction between the physical components of the galaxy. Then, the main parameters are examined and their effects on the spectral energy distribution of three prototype galaxies are highlighted. We conclude analyzing the capability of our galaxy models in reproducing the SEDs of real galaxies in the Local Universe and as function of redshift.

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Cited by 37 publications

References 22 publications

The globular cluster system of NGC 4374

The globular cluster system of NGC 4374

Study of stellar populations in the bulges of barred galaxies

Modelling galaxy spectra in presence of interstellar dust – III. From nearby galaxies to the distant Universe

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