相关论文: Age Estimates for Galaxies in Groups

A comparison is carried out among the star formation histories of early-type galaxies (ETG) in fossil groups, clusters and low density environments. Although they show similar evolutionary histories, a significant fraction of the fossils…

This paper is part of a series in which we perform a systematic comparison of the galaxy properties inhabiting compact groups, loose groups and the field. In this paper we focus our study to the age and the star formation in galaxies. For…

We review current progress in the study of the stellar populations of early-type galaxies, both locally and at intermediate redshifts. In particular, we focus on the ages of these galaxies and their evolution in hopes of determining the…

We investigate the Mg-sigma and <Fe>-sigma relations in a sample of 72 early-type galaxies drawn mostly from cluster and group environments using a homogeneous data-set which is well-calibrated onto the Lick/IDS system. The small intrinsic…

We present a general set of calculations decribing the chemical evolution of young massive galaxies and predict the evolution of the CO, O2, and dust abundances as a function of age and metallicity.

We explore the effects of environment in the evolution of late-type galaxies by studying the radial profiles of light- and mass-weighted metallicities of galaxies in two discrete environments: field and groups. We use a sample of 167…

This talk investigates the formation of early-type galaxies from a deliberately observational view point. I begin by reviewing the conclusions that can be reached by comparing the detailed properties of galaxies in present-day clusters,…

We present age and metallicities determinations based on narrow band continuum colors for the galaxies in the rich clusters A1185 and Coma. Using a new technique to extract luminosity-weighted age and [Fe/H] values for non-star-forming…

We report on a uniform comparative analysis of the fundamental parameters of early-type galaxies at z~1 down to a well defined magnitude limit (M_B\leq -20.0 in the field and M_B\leq -20.5 in the clusters). The changes in the M/L_B ratio…

Using up-to-date stellar models and isochrones we determine the age of 25 galactic halo clusters. The clusters are distributed into four groups according to metallicity. We measure the absolute age of a reference cluster in each group, and…

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…

Using optical-optical and optical-NIR colors, we analyze the radial dependence of age and metallicity inside massive (M* > 10^10.5 MSun), low-redshift (z<0.1), early-type galaxies (ETGs), residing in both high-density group regions and the…

Estimating ages for stars is difficult at best, but Galactic problems have their own requirements that go beyond those for other areas of astrophysics. As in other areas, asteroseismology is helping, and in this review I discuss some of the…

We report the results of a high quality spectral study of early-type galaxies within the Coma Cluster core. Stellar population analysis using Lick/IDS indices to break the age/metallicity degeneracy are presented, probing their formation…

We study star formation history and stellar metallicity distribution in galaxies in a Lambda cold dark matter universe using a hydrodynamic cosmological simulation. Our model predicts star formation rate declining in time exponentially from…

We present results of age and metallicity gradient analysis inferred from both optical and near-infrared surface photometry. The analysis is based on a sample of 36 nearby early-type galaxies, obtained from the Early Data Release of the…

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 core of the Coma cluster, the Virgo cluster,poor groups,and field galaxies. We…

Old open clusters are useful tools to study the Galactic disk properties, both present and past. Populous samples with properties determined both accurately and homogenously are necessary to draw reliable conclusions. We present here our…

Much progress has been achieved in the age-dating of old stellar systems, and even of individual stars in the field, in the more than sixty years since the evolution of low-mass stars was first correctly described. In this paper, I provide…

We present the first estimate of age, stellar metallicity and chemical abundance ratios, for an individual early-type galaxy at high-redshift (z = 1.426) in the COSMOS field. Our analysis is based on observations obtained with the X-Shooter…