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Related papers: The Milky Way Tomography with SDSS: II. Stellar Me…

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We explore the stellar metallicity distribution function of the Galactic halo based on SDSS ugriz photometry. A set of stellar isochrones is calibrated using observations of several star clusters and validated by comparisons with…

In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is also producing a massive spectroscopic database. We discuss determination of stellar parameters, such as effective temperature, gravity and…

Using the stellar atmospheric parameters such as effective temperature and metallicity derived from SDSS spectra for 2200 main sequence (MS) stars which were also observed by Beijing - Arizona - Taiwan - Connecticut (BATC) photometric…

Astrophysics of Galaxies · Physics 2015-06-16 Xiyan Peng , Cuihua Du , Zhenyu Wu , Jun Ma , Xu Zhou

We estimated the Galactic model parameters from the SDSS data reduced for two fields in the anti-centre direction of the Galaxy, $l= 180^{o}$, and symmetric relative to the Galactic plane, $b=+45^{o}$ and $b=-45^{o}$. The large size of each…

Astrophysics · Physics 2009-11-11 S. Ak , S. Bilir , S. Karaali , R. Buser

(Abridged) We perform an analysis of spectra and photometry for 22,770 stars included in the third data release (DR3) of the SDSS. We measure radial velocities and, based on a model-atmosphere analysis, derive estimates ofthe atmospheric…

Astrophysics · Physics 2009-09-29 C. Allende Prieto , T. C. Beers , R. Wilhelm , H. J. Newberg , C. M. Rockosi , B. Yanny , Y. S. Lee

We report on the distribution of metallicities, [Fe/H], for very metal-poor stars in the halo of the Galaxy. Although the primary information on the nature of the Metallicity Distribution Function (MDF) is obtained from the two major recent…

Based on the Beijing-Arizona-Taiwan-Connecticut (BATC) and Sloan Digital Sky Survey (SDSS) photometric data, we adopt SEDs fitting Method to evaluate the metallicity distribution for \sim40,000 main-sequence stars in the Galaxy. According…

Astrophysics of Galaxies · Physics 2015-06-03 Xiyan Peng , Cuihua Du , Zhenyu Wu

Based on the Sloan Digital Sky Survey (SDSS), we develop a new monte-carlo based method to estimate the photometric metallicity distribution function (MDF) for stars in the Milky Way. Compared with other photometric calibration methods,…

Astrophysics of Galaxies · Physics 2016-07-27 Jiayin Gu , Cuihua Du , Yingjie jing , Wenbo Zuo

We analyze a sample of tens of thousands of spectra of halo turnoff stars, obtained with the optical spectrographs of the Sloan Digital Sky Survey (SDSS), to characterize the stellar halo population "in situ" out to a distance of a few tens…

We study Milky Way kinematics using a sample of 18.8 million main-sequence stars with r<20 and proper-motion measurements derived from SDSS and POSS astrometry, including ~170,000 stars with radial-velocity measurements from the SDSS…

Astrophysics of Galaxies · Physics 2014-11-20 N. A. Bond , Z. Ivezic , B. Sesar , M. Juric , J. Munn

We study the metallicity distribution and kinematic properties of 4,680 A/F/G/K-type giant stars with $|z|>$ 5 kpc selected from the LAMOST spectroscopic survey. The metallicity distribution of giant stars with 5 $<|z|\leqslant$ 15 kpc can…

Astrophysics of Galaxies · Physics 2018-08-15 Shuai Liu , Cuihua Du , Heidi Jo Newberg , Yuqin Chen , Zhenyu Wu , Jun Ma , Xu Zhou , Zihuang Cao , Yonghui Hou , Yuefei Wang , Yong Zhang

The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliable metallicities of $\sim280,000$ stars with $-3.75 \lesssim$…

Astrophysics of Galaxies · Physics 2021-06-09 Anirudh Chiti , Anna Frebel , Mohammad K. Mardini , Tatsuya W. Daniel , Xiaowei Ou , Anastasiia V. Uvarova

We develop a method to estimate photometric metallicities by simultaneously fitting the dereddened colors u-g, g-r, r-i and i-z from the SDSS with those predicted by the metallicity-dependent stellar loci. The method is tested with a…

Astrophysics of Galaxies · Physics 2015-06-23 Haibo Yuan , Xiaowei Liu , Maosheng Xiang , Yang Huang , Bingqiu Chen

We used the ugr magnitudes of 1,437,467 F-G type main-sequence stars with metal abundance -2<[Fe/H]<+0.2 dex and estimated radial and vertical metallicity gradients for high Galactic-latitude fields (b>50) of the Milky Way Galaxy. The…

Astrophysics of Galaxies · Physics 2019-01-16 S. Tuncel Guctekin , S. Bilir , S. Karaali , O. Plevne , S. Ak

I present the mean metallicity distribution of stars in the Milky Way Galaxy based on photometry from the Sloan Digital Sky Survey. I utilize an empirically calibrated set of stellar isochrones developed in previous work to estimate the…

Astrophysics of Galaxies · Physics 2019-06-19 Deokkeun An

We study the metal abundances of F and G type stars in the Galactic disk and halo using the Canada-France-Hawaii Telescope Legacy Survey D4 field. For a sample of stars within 7 kpc of the Galactic plane, we derive mean abundance values of…

Astrophysics · Physics 2009-11-13 Y. Karatas , M. Kilic , O. Gunes , F. Limboz

Based on Sloan Digital Sky Survey (SDSS) photometric data, Gu developed a new Monte-Carlo-based method for estimating the stellar metallicity distribution functions (MDFs). This method enables a more reliable determination of MDFs compared…

Astrophysics of Galaxies · Physics 2019-06-05 Jiayin Gu , Cuihua Du , Wenbo Zuo

We analyze a sample of 3,944 low-resolution (R ~ 2000) optical spectra from the Sloan Digital Sky Survey (SDSS), focusing on stars with effective temperatures 5800 < Teff < 6300 K, and distances from the Milky Way plane in excess of 5 kpc,…

We interpret published CCD UBVI data to deduce the stellar density distribution and metallicity distribution function in the region from 2-8 kpc from the Galactic Plane, and compare our results to several star count models. A feature of…

Astrophysics · Physics 2009-11-07 S. Karaali , S. G. Ak , S. Bilir , Y. Karatas , G. Gilmore

We used the updated [Fe/H] abundances of 168 F-G type dwarfs and calibrated them to a third order polynomial in terms of reduced ultraviolet excess, $\delta_{0.41}$ defined with $ugr$ data in the SDSS. We estimated the $M_g$ absolute…

Astrophysics of Galaxies · Physics 2017-09-04 S. Tuncel Guctekin , S. Bilir , S. Karaali , O. Plevne , S. Ak , T. Ak , Z. F. Bostanci
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