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Related papers: A Robust Age Indicator for Old Stellar Populations

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The upcoming new generation of optical spectrographs on four-meter-class telescopes will provide invaluable information for reconstructing the history of star formation in individual galaxies up to redshifts of about 0.7. We aim at defining…

The determination of stellar populations of galaxies are important for studying the formation and evolution of galaxies, because all galaxies contain many stars and they evolve with galaxies. Spectra data are usually used to determine the…

Solar and Stellar Astrophysics · Physics 2013-02-04 Zhongmu Li

From photometric observations of elliptical galaxies, among which are both radio galaxies and radio-quiet objects, an investigation was carried out of the relationship `redshift -- age of the stellar system' $(\Delta z/\Delta t)$. By means…

Astrophysics · Physics 2009-06-23 O. V. Verkhodanov , Yu. N. Parijskij , A. A. Starobinsky

We present a study on the stellar age and metallicity distributions for 1105 galaxies using the STARLIGHT software on MaNGA integral field spectra. We derive age and metallicity gradients by fitting straight lines to the radial profiles,…

The ages of the oldest stars in the Galaxy indicate when star formation began, and provide a minimum age for the Universe. Radioactive dating of meteoritic material and stars relies on comparing the present abundance ratios of radioactive…

Very metal-poor halo stars are the best candidates for being among the oldest objects in our Galaxy. Samples of halo stars with age determination and detailed chemical composition measurements provide key information for constraining the…

We perform population synthesis modelling of a magnitude-limited sample of 4391 Luminous Red Galaxies selected from the Sloan Digital Sky Survey Data Release 4 (SDSS DR4). We fit measured spectral indices using a large library of high…

Astrophysics · Physics 2008-11-26 T. Barber , A. Meiksin , T. Murphy

The leading method for the determination of relevant stellar population parameters of unresolved extragalactic Globular Clusters is through the study of their integrated spectroscopy, where Balmer line-strength indices are considered to be…

Over the last few years, many studies have found an empirical relationship between the abundance of a star and its age. Here we estimate spectroscopic stellar ages for 178 825 red-giant stars observed by the APOGEE survey with a median…

We present a detailed spatial analysis of stellar populations based on long-slit optical spectra in a sample of eight luminous early-type galaxies selected from nearby sparse groups and pairs, three of them may be interacting with a galaxy…

Astrophysics of Galaxies · Physics 2018-06-11 D. A. Rosa , A. C. Milone , A. C. Krabbe , I. Rodrigues

Stellar population parameters derived from spectral line-strengths provide a powerful probe of galaxy properties and formation histories. We implement the machinery for extracting single-stellar-population-equivalent stellar population…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 S. C. Trager , R. S. Somerville

We study the internal radial gradients of the stellar populations in a sample comprising 522 early-type galaxies (ETGs) from the SAMI (Sydney- AAO Multi-object Integral field spectrograph) Galaxy Survey. We stack the spectra of individual…

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

[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 the HR-pyPopStar model, which provides a complete set (in ages) of high resolution (HR) Spectral Energy Distributions of Single Stellar Populations. The model uses the most recent high wavelength-resolution theoretical atmosphere…

Astrophysics of Galaxies · Physics 2021-07-28 I. Millán-Irigoyen , M. Mollá , M. Cerviño , Y. Ascasibar , M. L. García-Vargas , P. R. T. Coelho

Mean ages and metal abundances are estimated for the stellar populations in a sample of 115 E and S0 galaxies in the central 64'x70' of the Coma cluster. The estimates are based on the line indices Mg2, <Fe> and Hbeta, and the mass-to-light…

Astrophysics · Physics 2016-08-30 Inger Jorgensen

We present a Bayesian method to determine simultaneously the age, metallicity, distance modulus, and interstellar reddening by dust of any resolved stellar population, by comparing the observed and synthetic color magnitude diagrams on a…

Astrophysics of Galaxies · Physics 2019-05-08 V. H. Ramírez-Siordia , G. Bruzual , B. Cervantes Sodi , T. Bitsakis

For decades, studying quiescent galaxies beyond $z\sim1$ has been challenging due to the reliance on photometric spectral energy distributions, which are highly susceptible to degeneracies between age, metallicity, dust, and star-formation…

We present an analysis of stellar populations in passive galaxies in seven massive X-ray clusters at z=0.19-0.89. Based on absorption line strengths measured from our high signal-to-noise spectra, the data support primarily passive…

Astrophysics of Galaxies · Physics 2017-12-06 Inger Jorgensen , Kristin Chiboucas , Emily Berkson , Omega Smith , Marianne Takamiya , Alexa Villaume

Using the theoretical stellar population synthesis models of BC96, Kong et al. (2003) showed that some BATC colors and color indices could be used to disentangle the age and metallicity effect. They found that there is a very good relation…

Astrophysics · Physics 2014-10-13 Jun Ma , Xu Zhou , Jiansheng Chen