Extremely α-Enriched Globular Clusters in Early-Type Galaxies:A Step toward the Dawn of Stellar Populations?

@article{Puzia2006ExtremelyG,
  title={Extremely $\alpha$-Enriched Globular Clusters in Early-Type Galaxies:A Step toward the Dawn of Stellar Populations?},
  author={Thomas H. Puzia and Markus Kissler-Patig and Paul Goudfrooij},
  journal={The Astrophysical Journal},
  year={2006},
  volume={648},
  pages={383 - 388}
}
We compare [α/Fe], metallicity, and age distributions of globular clusters in elliptical, lenticular, and spiral galaxies, which we derive from Lick line index measurements. We find a large number of globular clusters in elliptical galaxies that reach significantly higher [α/Fe] values ([α/Fe] > 0.5) than any clusters in lenticular and spiral galaxies. Most of these extremely α-enriched globular clusters are old (t > 8 Gyr), and cover the metallicity range Pub Lcl changemark="ins">-1 ≲ [Z/H… 

Figures from this paper

Ages, metallicities and (α/Fe) ratios of globular clusters in NGC 147, 185 and 205
We present measurements of ages, metallicities and [α/Fe] ratios for 16 globular clusters (GCs) in NGC 147, 185 and 205 and of the central regions of the diffuse galaxy light in NGC 185 and 205. Our
THE OPTICAL COLORS OF GIANT ELLIPTICAL GALAXIES AND THEIR METAL-RICH GLOBULAR CLUSTERS INDICATE A BOTTOM-HEAVY INITIAL MASS FUNCTION
We report a systematic and statistically significant offset between the optical (g − z or B − I) colors of seven massive elliptical galaxies and the mean colors of their associated massive metal-rich
The age, metallicity and α-element abundance of Galactic globular clusters from single stellar population models
Establishing the reliability with which stellar population parameters can be measured is vital to extragalactic astronomy. Galactic globular clusters (GCs) provide an excellent medium in which to
The ACS Virgo Cluster Survey. XV. The Formation Efficiencies of Globular Clusters in Early-Type Galaxies: The Effects of Mass and Environment
The fraction of stellar mass contained in globular clusters (GCs), also measured by number as the specific frequency, is a fundamental quantity that reflects both a galaxy's early star formation and
COLOR–MAGNITUDE RELATIONS WITHIN GLOBULAR CLUSTER SYSTEMS OF GIANT ELLIPTICAL GALAXIES: THE EFFECTS OF GLOBULAR CLUSTER MASS LOSS AND THE STELLAR INITIAL MASS FUNCTION
Several recent studies have provided evidence for a “bottom-heavy” stellar initial mass function (IMF) in massive elliptical galaxies. Here we investigate the influence of the IMF shape on the
Dissolved Massive Metal-rich Globular Clusters Can Cause the Range of UV Upturn Strengths Found among Early-type Galaxies
I discuss a scenario in which the ultraviolet (UV) upturn of giant early-type galaxies (ETGs) is primarily due to helium-rich stellar populations that formed in massive metal-rich globular clusters
Star-forming galaxies at z∼ 2 and the formation of the metal-rich globular cluster population
We examine whether the super star-forming (super-SF) clumps (R∼ 1–3 kpc; M∼ 108– 109.5 M⊙) now known to be a key component of star-forming galaxies at z∼ 2 could be the formation sites of the locally
The Formation of Globular Cluster Systems in Massive Elliptical Galaxies: Globular Cluster Multimodality from Radial Variation of Stellar Populations
The most massive elliptical galaxies show a prominent multimodality in their globular cluster system color distributions. Understanding the mechanisms that lead to multiple globular cluster
THE AGES, METALLICITIES, AND ALPHA ELEMENT ENHANCEMENTS OF GLOBULAR CLUSTERS IN THE ELLIPTICAL NGC 5128: A HOMOGENEOUS SPECTROSCOPIC STUDY WITH GEMINI/GEMINI MULTI-OBJECT SPECTROGRAPH
We present new integrated light spectroscopy of globular clusters (GCs) in NGC 5128, a nearby giant elliptical galaxy less than 4 Mpc away, in order to measure radial velocities and derive ages,
Dynamical Evolution of Globular Cluster Systems Formed in Galaxy Mergers: Deep Hubble Space Telescope Advanced Camera for Surveys Imaging of Old and Intermediate-Age Globular Clusters in NGC 3610
The Advanced Camera for Surveys on board the Hubble Space Telescope has been used to obtain deep, high-resolution images of the giant elliptical galaxy NGC 3610, a well-established remnant of a
...
...

References

SHOWING 1-10 OF 49 REFERENCES
Integrated spectroscopy of bulge globular clusters and fields - II: implications for population synthesis models and elliptical galaxies
An empirical calibration is presented for the synthetic Lick indices (e.g. Mg2, ‹Fe›, H s, etc.) of Simple Stellar Population (SSP) models that for the first time extends up to solar metallicity.
VLT spectroscopy of globular cluster systems - II. Spectroscopic ages, metallicities and [α/Fe] ratios of globular clusters in early-type galaxies
An analysis of ages, metallicities, and [α/Fe] ratios of globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized in Puzia et al. (2004, A&A, 415,
Deep Luminosity Functions of Old and Intermediate-Age Globular Clusters in NGC 1316: Evidence for Dynamical Evolution of Second-Generation Globular Clusters*
The Advanced Camera for Surveys on board the Hubble Space Telescope has been used to obtain deep high-resolution images of the giant early-type galaxy NGC 1316, an obvious merger remnant. These
Keck Spectroscopy of Globular Clusters around NGC 1399
We report moderate-resolution, high signal-to-noise ratio spectroscopy of globular clusters around NGC 1399, the central cD galaxy in the Fornax Cluster. We address issues as diverse as elemental
Old Globular Clusters Masquerading as Young in NGC 4365
High signal-to-noise ratio, low-resolution spectra have been obtained for 22 globular clusters (GCs) in NGC 4365. Some of these were selected as probable representatives of an intermediate-age (2–5
Evidence for an Intermediate-Age, Metal-rich Population of Globular Clusters in NGC 4365*
We present spectroscopy for globular clusters (GCs) in the elliptical galaxy NGC 4365, obtained with the Low-Resolution Imaging Spectrograph on the Keck I telescope. Previous studies have shown that
The age distribution of massive star clusters in the antennae galaxies
We determine the age distribution of star clusters in the Antennae galaxies (NGC 4038/9) for two mass-limited samples (M > 3 × 104 M☉ and M > 2 × 105 M☉). This is based on integrated broadband UBVI
New light on the formation and evolution of M 31 and its globular cluster system
We present spectroscopic ages, metallicities, and (α/Fe) ratios for 70 globular clusters in M 31 that were derived from Lick line-index measurements. A new interpolation technique of age-metallicity
The Epochs of Early-Type Galaxy Formation as a Function of Environment
The aim of this paper is to set constraints on the epochs of early-type galaxy formation through the "archaeology" of the stellar populations in local galaxies. Using our models of absorption-line
The Globular Cluster System of NGC 5128. II. Ages, Metallicities, Kinematics, and Formation
We present a study of the nearby postmerger giant elliptical galaxy NGC 5128 (Centaurus A), in which we use the properties of its globular cluster (GC) and planetary nebula (PN) systems to constrain
...
...