NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-21 T02:29:21 PDT
Help | Comment | NED Home

For refcode 2006ApJ...648..383P:
Retrieve 14 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2006ApJ...648..383P Extremely {alpha}-Enriched Globular Clusters in Early-Type Galaxies:A Step toward the Dawn of Stellar Populations? Thomas H. Puzia, Markus Kissler-Patig, and Paul Goudfrooij Abstract. We compare [{alpha}/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 [{alpha}/Fe] values ([{alpha}/Fe]>0.5) than any clusters in lenticular and spiral galaxies. Most of these extremely {alpha}-enriched globular clusters are old (t>8 Gyr), and cover the metallicity range -1<~[Z/H]<~0. A comparison with supernova yield models suggests that the progenitor gas clouds of these globular clusters must have been predominantly enriched by massive stars (>~20M_sun_), with little contribution from lower mass stars. The measured [{alpha}/Fe] ratios are also consistent with yields of very massive pair-instability supernovae (~130 -- 190 M_sun_). Both scenarios imply that the chemical enrichment of the progenitor gas was completed on extremely short timescales of the order of a few Myr. Given the lower [{alpha}/Fe] average ratios of the diffuse stellar population in early-type galaxies, our results suggest that these extremely {alpha}-enhanced globular clusters could be members of the very first generation of star clusters formed, and that their formation epochs would predate the formation of the majority of stars in giant early-type galaxies. Key words: Galaxies: Evolution, Galaxies: Formation, Galaxies: Star Clusters, Galaxy: Globular Clusters: General
Retrieve 14 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home