An accurate relative age estimator for globular clusters
نویسندگان
چکیده
منابع مشابه
Relative Ages of Globular Clusters
Ages of extragalactic globular clusters can provide valuable insights into the formation and evolution of galaxies. In this contribution the photometric methods of age dating old globular cluster systems are summarised. The spectroscopic approach is reviewed with an emphasis of the right choice of age diagnostics. We present a new method of quantifying the relatively best age-sensitive spectros...
متن کاملThe Age of Globular Clusters
I review here recent developments which have affected our understanding of both the absolute age of globular clusters and the uncertainties in this age estimate, and comment on the implications for cosmological models. This present estimate is in agreement with the range long advocated by David Schramm. The major uncertainty in determining ages of globular clusers based upon the absolute magnit...
متن کاملAccurate Internal Proper Motions of Globular Clusters
We have undertaken a long term program to measure high precision proper motions of nearby Galactic globular cluster (GC) stars using multi-epoch observations with the WFPC2 and the ACS cameras on-board the Hubble Space Telescope. The proper motions are used to study the internal cluster kinematics, and to obtain accurate cluster distances. In this paper, we also show how the proper motions of t...
متن کاملThe Relative Ages of Galactic Globular Clusters
We present a review of the present state of knowledge regarding the relative ages of Galactic globular clusters. First, we discuss the relevant galaxy formation models and describe the detailed predictions they make with respect to the formation timescale and chemical evolution of the globular clusters. Next, the techniques used to estimate globular cluster ages are described and evaluated with...
متن کاملAge Estimates for Globular Clusters in Ngc 1399
We present high signal-to-noise Keck spectra for 10 globular clusters associated with the giant Fornax elliptical NGC 1399, and compare measured line indices with current stellar population models. Our data convincingly demonstrate, for the first time, that at least some of the clusters in a giant elliptical galaxy have super-solar abundance ratios, similar to the host galaxy. From Hβ line-stre...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1996
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/283.2.683