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相关论文: New metallicity calibration down to [Fe/H] = -2.75…

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By using a large sample of published spectroscopic iron abundances, we point out the importance of gravity correction in deriving more accurate metal abundances for RR Lyrae stars. For the 197 stars with multiple spectra we find overall…

太阳与恒星天体物理 · 物理学 2023-10-18 Geza Kovacs , Johanna Jurcsik

Based on synthetic flux spectra calculated from theoretical atmospheric models, a calibration of temperature and metallicity for the dwarfs observed in the Beijing-Arizona-Taiwan-Connecticut (BATC) multicolor photometric system is presented…

天体物理学 · 物理学 2009-11-10 Cui-hua Du , Xu Zhou , Jun Ma , Jian-rong Shi , Alfred Bing-Chih Chen , Zhao-ji Jiang , Jian-sheng

The CM Draconis system comprises two eclipsing mid-M dwarfs of nearly equal mass in a 1.27-day orbit. This well-studied eclipsing binary has often been used for benchmark tests of stellar models, since its components are amongst the lowest…

Studies of the early chemical evolution of some larger dwarf galaxies ( $>10^7$ solar masses) are limited by the small number of stars known at low metallicities in these systems. Here we present metallicities and carbon abundances for…

星系天体物理 · 物理学 2020-10-14 Anirudh Chiti , Kylie Y. Hansen , Anna Frebel

A new metallicity distribution and an age-metallicity relation are presented for 437 nearby F and G turn-off and sub-giant stars selected from radial velocity data of Nidever et al. Photometric metallicities are derived from uvby-H\beta…

天体物理学 · 物理学 2009-11-11 Y. Karatas , S. Bilir , W. J. Schuster

It is shown that bright cluster dwarf ellipticals follow a relation between metallicity and apparent flattening. Rounder dwarfs tend to be more metal-rich. The evidence is based on colour as well as spectroscopic line-strength data from the…

天体物理学 · 物理学 2009-11-07 Fabio D. Barazza , Bruno Binggeli

We apply the stellar locus method to synthetic $(BP-RP)_{XPSP}$ and $(BP-G)_{XPSP}$ colors derived from corrected Gaia BP/RP (XP) spectra to obtain precise estimates of metallicity for about 100 million stars in the Milky Way (34 million…

太阳与恒星天体物理 · 物理学 2025-02-04 Bowen Huang , Haibo Yuan , Shuai Xu , Kai Xiao , Maosheng Xiang , Yang Huang , Timothy C. Beers

We present abundances of globular clusters in the Milky Way and Fornax from integrated light spectra. Our goal is to evaluate the consistency of the integrated light analysis relative to standard abundance analysis for individual stars in…

星系天体物理 · 物理学 2017-01-11 J. E. Colucci , R. A. Bernstein , A. McWilliam

We present updated stellar population models appropriate for old ages (>1 Gyr) and covering a wide range in metallicities (-1.5<[Fe/H]<0.3). These models predict the full spectral variation associated with individual element abundance…

星系天体物理 · 物理学 2018-02-28 Charlie Conroy , Alexa Villaume , Pieter van Dokkum , Karin Lind

Hipparcos parallaxes and proper motions have made it possible to construct Hertzsprung-Russell (HR) diagrams of nearby clusters with unprecedented accuracy. The standard deviation of high fidelity non-binary non-variable stars about a model…

天体物理学 · 物理学 2009-11-07 A. C. Quillen

Through a homogeneous analysis of spectroscopic literature data of red giant stars, we determine the radial metallicity profiles of 30 dwarf galaxies in the Local Group. We explore correlations between the calculated metallicity gradients…

星系天体物理 · 物理学 2022-09-14 S. Taibi , G. Battaglia , R. Leaman , A. Brooks , C. Riggs , F. Munshi , Y. Revaz , P. Jablonka

We have used new parallax measurements, obtained by the Hipparcos satellite, of fifteen nearby, metal-poor stars to re-define the subdwarf main-sequence. All of these stars have parallaxes determined to an accuracy of at least 12 %.…

天体物理学 · 物理学 2009-10-30 I. Neill Reid

Taking advantage of the near-infrared calcium triplet lines, we determine metallicities for a sample of more than 3,500 red giant stars in the field of the Small Magellanic Cloud (SMC). We find a median metallicity of [Fe/H]=-1.05$\pm$0.01…

星系天体物理 · 物理学 2025-11-04 M. Navabi , R. Carrera , N. E. D. Noël , M. De Leo

We have measured the emission line ratios in a sample of 34 CFRS star-forming galaxies with redshifts between 0.5 < z < 1.0, and computed their metallicities by means of the empirically-calibrated R_23 metallicity estimator introduced by…

天体物理学 · 物理学 2009-10-31 C. M. Carollo , S. J. Lilly

The stellar metallicity is a direct measure of the amount of metals present in a galaxy, as a large part of the metals lie in its stars. In this paper we investigate new stellar metallicity indicators suitable for high-z galaxies studying…

The location of M dwarfs in the V-K_s--M_Ks color-magnitude diagram (CMD) has been shown to correlate with metallicity. We demonstrate that previous empirical photometric calibrations of M dwarf metallicity exploiting this correlation…

地球与行星天体物理 · 物理学 2015-05-19 Kevin C. Schlaufman , Gregory Laughlin

We tested the capability of a Bayesian procedure to calibrate both the helium abundance and the mixing length parameter ($\alpha_{ML}$), using precise photometric data for main-sequence (MS) stars in a cluster with negligible reddening and…

星系天体物理 · 物理学 2020-12-23 E. Tognelli , M. Dell'Omodarme , G. Valle , P. G. Prada Moroni , S. Degl'Innocenti

We extend the colour calibration of the widely used BaSeL standard stellar library (Lejeune, Cuisinier, & Buser 1997, 1998) to non-solar metallicities, down to [Fe/H] ~ -2.0 dex. Surprisingly, we find that at the present epoch it is…

天体物理学 · 物理学 2009-11-07 P. Westera , T. Lejeune , R. Buser , F. Cuisinier , G. Bruzual A.

Assuming that in the atmospheres of low-mass, metal-poor red giant stars, 1-D models based on LTE accurately predict the abundance of iron from Fe II, we derive a globular cluster metallicity scale based on the equivalent widths of Fe II…

天体物理学 · 物理学 2009-07-28 Robert P. Kraft , Inese I. Ivans

We performed a new calibration of the Stroemgren metallicity index m1 based on the b-y color of cluster red giant stars. The current Metallicity-Index-Color relation is not linear in the color range 0.40 < b-y < 1.0, but provides iron…