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相关论文: Photometric Abundances for G-Dwarfs: A Cautionary …

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Several recent studies of Solar twins in the Solar neighbourhood have shown a tight correlation between various elemental abundances and age, in particular [Y/Mg]. If this relation is real and valid for other types of stars as well as…

星系天体物理 · 物理学 2016-12-21 S. Feltzing , L. M. Howes , P. J. McMillan , E. Stonkute

Based on SDSS g, r and SCUSS (South Galactic Cap of u-band Sky Survey) $u$ photometry, we develop a photometric calibration for estimating the stellar metallicity from $u-g$ and $g-r$ colors by using the SDSS spectra of 32,542 F- and G-type…

The present sample of nearby bulgelike dwarf stars has kinematics and metallicities characteristic of a probable inner disk or bulge origin. Ages derived by using isochrones give 10-11 Gyr for these stars and metallicities are in the range…

天体物理学 · 物理学 2009-11-07 Luciana Pompeia , Beatriz Barbuy , Michel Grenon

Metallicities ([Fe/H]) from low resolution spectroscopy obtained with the Very Large Telescope (VLT) are presented for 98 RR Lyrae and 3 short period Cepheids in the bar of the Large Magellanic Cloud. Our metal abundances have typical…

天体物理学 · 物理学 2009-11-10 R. G. Gratton , A. Bragaglia , G. Clementini , E. Carretta , L. Di Fabrizio , M. Maio , E. Taribello , -

An analysis of some properties of stellar models as a function of metallicity Z (and helium content Y) is presented, with special attention to those stars with metallicities higher than twice or three times solar. It is shown that the…

天体物理学 · 物理学 2007-05-23 N. Mowlavi , G. Meynet , A. Maeder , D. Schaerer , C. Charbonnel

The metal content of a galaxy's interstellar medium reflects the interplay between different evolutionary processes such as feedback from massive stars and the accretion of gas from the intergalactic medium. Despite the expected abundance…

An abundance analysis is presented and discussed for a sample of 14 RV Tauri stars. The present abundance data and those from our previous papers and by other workers are combined in an attempt to further understanding of the dust-gas…

天体物理学 · 物理学 2009-11-10 Sunetra Giridhar , David L. Lambert , Bacham E. Reddy , Guillermo Gonzalez , David Yong

Internal mixing on the giant branch is an important process which affects the evolution of stars and the chemical evolution of the galaxy. While several mechanisms have been proposed to explain this mixing, better empirical constraints are…

We describe the methodology required for estimation of photometric estimates of metallicity based on the SDSS gri passbands, which can be used to probe the properties of main-sequence stars beyond ~ 10 kpc, complementing studies of nearby…

The metal content of clusters of galaxies and its relation to their stellar content is revisited making use of a cluster sample for which all four basic parameters are homogeneously measured within consistent radii, namely core-excised…

星系天体物理 · 物理学 2015-06-22 A. Renzini , S. Andreon

We present abundance analyses based on high dispersion and high signal-to-noise ratio Magellan spectra of two highly microlensed Galactic bulge stars in the region of the main sequence turnoff with Teff ~ 5650 K. We find that…

太阳与恒星天体物理 · 物理学 2009-06-25 Judith G. Cohen , Ian B. Thompson , Takahiro Sumi , Ian Bond , Andrew Gould , Jennifer A. Johnson , Wenjin Huang , Greg Burley

We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 square arcminute area at the optical center of the LMC bar. These are the first spectroscopic abundance…

天体物理学 · 物理学 2009-11-10 Andrew A. Cole , E. Tolstoy , J. S. Gallagher , T. A. Smecker-Hane

We have revisited the problem of metallicity prediction of RR Lyrae stars from their near-infrared light curves in the Cousins I waveband. Our study is based on high-quality time-series photometry and state-of-the-art high-resolution…

太阳与恒星天体物理 · 物理学 2021-10-20 István Dékány , Eva K. Grebel , Grzegorz Pojmański

Ultra-faint dwarf galaxies (UFDs, $M_* < 10^5 M_\odot$) offer unique insights into early chemical evolution in low-mass systems. However, interpreting their metallicity distribution functions (MDFs) has been challenging due to limited…

We investigate the radial metallicity gradients and azimuthal metallicity distributions on the Galactocentric $X$--$Y$ plane using mono-temperature stellar populations selected from LAMOST MRS young stellar sample. The estimated radial…

星系天体物理 · 物理学 2023-06-14 Chun Wang , Haibo Yuan , Maosheng Xiang , Yuan-Sen Ting , Yang Huang , Xiaowei Liu

We present an analysis of $UBVRI$ data from the Selected Area SA 141. By applying recalibrated methods of measuring ultraviolet excess (UVX), we approximate abundances and absolute magnitudes for 368 stars over 1.3 square degrees out to…

星系天体物理 · 物理学 2009-11-13 Michael H. Siegel , Yuksel Karatas , I. Neill Reid

Observations of globular clusters (GCs) and field stars in the halos of the giant elliptical galaxy Cen A and the spiral galaxy M31 show a large range of cluster-to-star number ratios ('specific frequencies'). The cluster-to-star ratio…

We have identified 317 stars included in the Hipparcos astrometric catalogue which have parallaxes measured to a precision of better than 15%, and whose location in the (M_V, (B-V)_T) diagram implies a metallicity comparable to or less than…

天体物理学 · 物理学 2009-10-31 I. Neill Reid , F. van Wyk , F. Marang , G. Roberts , D. Kilkenny , S. Mahoney

We report iron and titanium abundance measurements from high resolution spectra in a volume-limited sample of 106 M0 and M0.5 dwarf stars. The sample includes stars north of the celestial equator and closer than 29 parsecs. The results…

太阳与恒星天体物理 · 物理学 2020-04-29 Vincent M. Woolf , George Wallerstein

We present a metallicity analysis of 83 late-type giants within the central 1 pc of the Milky Way. K-band spectroscopy of these stars were obtained with the medium-spectral resolution integral-field spectrograph NIFS on Gemini North using…

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