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相关论文: The Metallicity Distribution Functions of SEGUE G …

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We employ measurements of the [alpha/Fe] ratio derived from low-resolution (R~2000) spectra of 17,277 G-type dwarfs from the SEGUE survey to separate them into likely thin- and thick-disk subsamples. Both subsamples exhibit strong gradients…

Using G dwarfs from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey, we have determined a vertical metallicity gradient over a large volume of the Milky Way's disk, and examined how this gradient varies for…

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…

The observed radial and vertical metallicity distribution of old stars in the Milky Way disk provides a powerful constraint on the chemical enrichment and dynamical history of the disk. We present the radial metallicity gradient,…

The chemical evolution of the Milky Way is investigated using a dual-phase metal-enriched infall model in which primordial gas fuels the earliest epoch of star formation, followed by the ongoing formation of stars from newly accreted gas.…

天体物理学 · 物理学 2009-11-07 Yeshe Fenner , Brad K. Gibson

We present an online catalog of distance determinations for $\rm 6036$ K giants, most of which are members of the Milky Way's stellar halo. Their medium-resolution spectra from SDSS/SEGUE are used to derive metallicities and rough gravity…

We present the first results of a study where we determine the metallicity distribution function in the Galactic disks as a function of height above the Galactic plane. Observations in the Stromgren photometric system enables us to identify…

天体物理学 · 物理学 2008-07-11 Anna S. Arnadottir , Sofia Feltzing , Ingemar Lundstrom

We present a revised metallicity distribution of dwarfs in the solar neighbourhood. This distribution is centred on solar metallicity. We show that previous metallicity distributions, selected on the basis of spectral type, are biased…

天体物理学 · 物理学 2009-11-06 Misha Haywood

The entire evolution of the Milky Way, including its mass-assembly and star-formation history, is imprinted onto the chemo-dynamical distribution function of its member stars, f(x, v, [X/H]), in the multi-dimensional phase space spanned by…

星系天体物理 · 物理学 2015-06-18 Kohei Hattori , Yuzuru Yoshii , Timothy C. Beers , Daniela Carollo , Young Sun Lee

We fit an Extended Distribution Function (EDF) to K giants in the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey. These stars are detected to radii ~80 kpc and span a wide range in [Fe/H]. Our EDF, which depends…

星系天体物理 · 物理学 2016-05-25 Payel Das , James Binney

We extend models of our Galaxy based on distribution functions (DFs) that are analytic functions of the action integrals to extended distribution functions (EDFs), which have an analytic dependence on metallicity as well. We use a simple,…

星系天体物理 · 物理学 2015-06-03 Jason L. Sanders , James Binney

We derive a new metallicity distribution of G dwarfs in the solar neighbourhood, using uvby photometry and up-to-date parallaxes. Our distribution comprises 287 G dwarfs within 25 pc from the Sun, and differs considerably from the classic…

天体物理学 · 物理学 2015-06-24 Helio J. Rocha-Pinto , Walter J. Maciel

We present a low metallicity map of the Milky Way consisting of $\sim$111,000 giants with $-3.5 \lesssim$ [Fe/H] $\lesssim -$0.75, based on public photometry from the second data release of the SkyMapper survey. These stars extend out to…

星系天体物理 · 物理学 2021-04-28 Anirudh Chiti , Mohammad K. Mardini , Anna Frebel , Tatsuya Daniel

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 a carefully constructed sample of dwarf stars, a new optical-near infrared photometric calibration to estimate the metallicity of late-type K and early-to-mid-type M dwarfs is presented. The calibration sample has two parts; the…

太阳与恒星天体物理 · 物理学 2015-06-24 Neda Hejazi , Michael M. De Robertis , Peter C. Dawson

We examine the metallicity distribution of the Galactic thick disk using F, G, and K dwarf stars selected from the Sloan Digital Sky Survey, Data Release 8. Using the large sample of dwarf stars with proper motions and spectroscopically…

星系天体物理 · 物理学 2012-11-29 Kenneth Carrell , Yuqin Chen , Gang Zhao

We measure the two-point correlation function of G-dwarf stars within 1-3 kpc of the Sun in multiple lines-of-sight using the Schlesinger et al. G-dwarf sample from the SDSS SEGUE survey. The shapes of the correlation functions along…

The Galactic disk is one of the main components of the Milky Way, which contributes most of the luminosity. Its structure is essential for understanding the formation and evolution of the Milky Way. Using 174,443 K-type dwarf stars observed…

星系天体物理 · 物理学 2024-07-15 Xi-Can Tang , Hao Tian , Jing Li , Bing-qiu Chen , Yi-Rong Chen , Chao Liu , Dan Qiu

We present stellar metallicities in Leo I, Leo II, IC 1613, and Phoenix dwarf galaxies derived from medium (F390M) and broad (F555W, F814W) band photometry using the Wide Field Camera 3 (WFC3) instrument aboard the Hubble Space Telescope.…

星系天体物理 · 物理学 2015-06-03 Teresa L. Ross , Jon A. Holtzman , Abhijit Saha , Barbara J. Anthony-Twarog
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