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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 new optical spectroscopy for 342 R<18 galaxies in the Shapley Supercluster obtained with the AAOmega facility at the Anglo-Australian Telescope. We describe the observations and measurements of central velocity dispersion,…

Astrophysics · Physics 2009-11-13 Russell J. Smith , John R. Lucey , Michael J. Hudson

In this third paper of a series on the precision of obtaining ages of stellar populations using the full spectrum fitting technique, we examine the precision of this technique in deriving possible age spreads within a star cluster. We test…

Astrophysics of Galaxies · Physics 2021-05-12 Randa Asa'd , Paul Goudfrooij , A. M. As'ad , H. G. El-Mir , L. Begum , A. Aljasmi , O. Almatroushi

[Abridged] We present new model predictions for 16 Lick absorption line indices from Hdelta through Fe5335, and UBV colors for single stellar populations (SPs) with ages ranging between 1 and 15 Gyr, [Fe/H] ranging from -1.3 to +0.3, and…

Astrophysics · Physics 2009-11-11 Ricardo P. Schiavon

We are motivated by the recent measurements of dust opacity indices beta around young stellar objects (YSOs), which suggest that efficient grain growth may have occurred earlier than the Class I stage. The present work makes use of abundant…

Solar and Stellar Astrophysics · Physics 2017-05-24 Jennifer I-Hsiu Li , Hauyu Baobab Liu , Yasuhiro Hasegawa , Naomi Hirano

The ages of the oldest stellar objects in our galaxy provide an independent test of the current cosmological model as they give a lower limit to the age of the Universe. Recent accurate parallaxes by the Gaia space mission, accurate…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-01 Raul Jimenez , Andrea Cimatti , Licia Verde , Michele Moresco , Benjamin Wandelt

(ABRIDGED) We assess the systematic uncertainties in (young) cluster age, mass, and - to a lesser extent - extinction and metallicity determinations, based on broad-band imaging observations with the Hubble Space Telescope. Our aim here is…

Using EPS we present high resolution (0.3 \AA, HRes) ISEDs from 3000 to 7000 \AA and Lick/IDS absorption-line indices, for an extensive set of instantaneous burst binary stellar populations (BSPs) with binary interactions. The ages of the…

Astrophysics · Physics 2009-11-13 Fenghui Zhang , Lifang Li , Zhanwen Han

We present a comprehensive analysis of the ability of current stellar population models to reproduce the optical (ugriz) and near infra-red (JHK) colours of a small sample of well-studied nearby elliptical and S0 galaxies. We find broad…

Oxygen and carbon are important elements in stellar populations. Their behavior refers to the formation history of the stellar populations. C and O abundances would also obviously influence stellar opacities and the overall metal abundance…

Solar and Stellar Astrophysics · Physics 2016-12-21 Z. S. Ge , S. L. Bi , Y. Q. Chen , T. D. Li , J. K. Zhao , K. Liu , Fergusion J. W. , Y. Q. Wu

The expansion history of the Universe can be constrained in a cosmology-independent way by measuring the differential age evolution of cosmic chronometers. This yields a measurement of the Hubble parameter $H(z)$ as a function of redshift.…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-15 Michele Moresco , Raul Jimenez , Licia Verde , Lucia Pozzetti , Andrea Cimatti , Annalisa Citro

We present homogeneous scales of ages and metallicities for star clusters from very young objects, through intermediate-age ones up to the oldest known clusters. All the selected clusters have integrated spectra in the visible range, as…

Astrophysics · Physics 2009-11-10 J. F. C. Santos , A. E. Piatti

Using EPS we present 13 refined Lick/IDS absorption-line indices for an extensive set of instantaneous-burst binary stellar populations (BSPs) at high resolution (0.3 \AA) of various age and metallicity (1-15Gyr, 0.004-0.03), and 38 indices…

Astrophysics · Physics 2009-11-11 Fenghui Zhang , Lifang Li

Stellar ages are key to improving our understanding of different astrophysical phenomena. However, many techniques to estimate stellar ages are highly model-dependent. The lithium depletion boundary (LDB), based on the presence or absence…

We report on the strengths of three spectral indicators - Mg_2, Hbeta, and Hn/Fe - in the integrated light of a sample of 100 field and cluster E/S0 galaxies. The measured indices are sensitive to age and/or and metallicity variations…

Astrophysics · Physics 2009-10-31 K. D. Concannon , J. A. Rose , N. Caldwell

[Abridged]. We present SEDs for single-age, single-metallicity stellar populations (SSPs) covering the optical range at resolution 2.3A (FWHM). These SEDs constitute our base models, as they combine scaled-solar isochrones with MILES…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-27 A. Vazdekis , P. Sánchez-Blázquez , J. Falcón-Barroso , A. J. Cenarro , M. A. Beasley , N. Cardiel , J. Gorgas , R. F. Peletier

We present line-strengths and kinematics from the central regions of 32 galaxies with Hubble types ranging from E to Sbc. Spectral indices, based on the Lick system, are measured in the optical and near infra-red (NIR). The 24 indices…

Astrophysics · Physics 2008-11-26 R. N. Proctor , A. E. Sansom

The star formation, mass assembly and chemical enrichment histories of galaxies, and their present distributions of dark matter, remain encoded in their stellar populations. Distinguishing the actual distribution functions of stellar age,…

Astrophysics · Physics 2009-11-11 Rosemary F. G. Wyse , Gerard Gilmore

[...] The aim of this paper is to study the precision and theoretical biases in the age determinations of halo stars adopting both asteroseismic and classic observational constraints. [...] We adopt the well-tested SCEPtER pipeline,…

Solar and Stellar Astrophysics · Physics 2023-03-15 S. Moser , G. Valle , M. Dell'Omodarme , S. Degl'Innocenti , P. G. Prada Moroni

We have obtained 2D spectral data for a sample of 58 nearby S0 galaxies with the Multi-Pupil Spectrograph of the 6m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. The Lick indices H-beta, Mgb, and…

Astrophysics · Physics 2009-11-13 Olga K. Sil'chenko