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

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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…

Astrophysics of Galaxies · Physics 2012-11-29 Kenneth Carrell , Yuqin Chen , Gang Zhao

We performed a spectroscopic survey of nearly 700 stars probing the galactic thick disc far from the solar neighbourhood towards the galactic coordinates (l~277, b~47). The derived effective temperatures, surface gravities and overall…

Astrophysics of Galaxies · Physics 2015-05-30 G. Kordopatis , A. Recio-Blanco , P. de Laverny , G. Gilmore , V. Hill , R. F. G. Wyse , A. Helmi , A. Bijaoui , M. Zoccali , O. Bienaymé

Population-level studies of Milky Way satellites used to constrain dark matter or the threshold of galaxy formation often rely on velocity dispersions and metallicities derived from heterogeneous spectroscopic analyses. Systematic…

Astrophysics of Galaxies · Physics 2026-02-12 Marla Geha

We investigate the metallicity dependence of HI surface densities in star-forming regions along many lines of sight within 70 nearby galaxies, probing kpc to 50 pc scales. We employ HI, SFR, stellar mass, and metallicity (gradient)…

Astrophysics of Galaxies · Physics 2018-08-08 Andreas Schruba , Shmuel Bialy , Amiel Sternberg

The Hubble Space Telescope has been used to obtain WFPC2 (V,I) photometry for a sample of 10,000 red giant stars in the outer halo of the giant elliptical NGC 5128. Comparison with the fiducial RGBs of Milky Way globular clusters and model…

Astrophysics · Physics 2009-10-31 G. L. H. Harris , W. E. Harris , G. B. Poole

We analyze the anisotropy profile of the Milky Way's smooth, diffuse stellar halo using SDSS/SEGUE blue horizontal branch stars and SDSS/SEGUE and LAMOST K giants. These intrinsically luminous stars allow us to probe the halo to…

Astrophysics of Galaxies · Physics 2021-10-04 Sarah A. Bird , Xiang-Xiang Xue , Chao Liu , Juntai Shen , Chris Flynn , Chengqun Yang , Gang Zhao , Hai-Jun Tian

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…

Astrophysics of Galaxies · Physics 2015-06-18 Kohei Hattori , Yuzuru Yoshii , Timothy C. Beers , Daniela Carollo , Young Sun Lee

We determine photometric metal abundance estimates for individual main-sequence stars in the Virgo Overdensity (VOD), which covers almost 1000 deg^2 on the sky, based on a calibration of the metallicity sensitivity of stellar isochrones in…

We present low-resolution MMT Hectospec spectroscopy of 594 candidate Monoceros stream member stars. Based on strong color-magnitude diagram overdensities, we targeted three fields within the stream's footprint, with 178 deg < l < 203 deg…

Astrophysics of Galaxies · Physics 2012-08-28 Aaron M. Meisner , Anna Frebel , Mario Juric , Douglas P. Finkbeiner

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…

In the fourth paper of this series, we present the metallicity-dependent Sloan Digital Sky Survey (SDSS) stellar color loci of red giant stars, using a spectroscopic sample of red giants in the SDSS Stripe 82 region. The stars span a range…

Solar and Stellar Astrophysics · Physics 2022-10-31 Ruoyi Zhang , Haibo Yuan , Xiaowei Liu , Maosheng Xiang , Yang Huang , Bingqiu Chen

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,…

We present spectroscopic metallicities of individual stars in seven gas-rich dwarf irregular galaxies (dIrrs), and we show that dIrrs obey the same mass-metallicity relation as the dwarf spheroidal (dSph) satellites of both the Milky Way…

Astrophysics of Galaxies · Physics 2013-12-02 Evan N. Kirby , Judith G. Cohen , Puragra Guhathakurta , Lucy Cheng , James S. Bullock , Anna Gallazzi

We derive distance, density and metallicity distribution of the stellar Monoceros Overdensity (MO) in the outer Milky Way, based on deep imaging with the Subaru Telescope. We applied CMD fitting techniques in three stripes at galactic…

We present a statistical parallax study of nearly 2,000 M subdwarfs with photometry and spectroscopy from the Sloan Digital Sky Survey. Statistical parallax analysis yields the mean absolute magnitudes, mean velocities and velocity…

Solar and Stellar Astrophysics · Physics 2015-06-12 John J. Bochanski , Antonia Savcheva , Andrew A. West , Suzanne L. Hawley

We map the stellar structure of the Galactic thick disk and halo by applying color-magnitude diagram (CMD) fitting to photometric data from the SEGUE survey, allowing, for the first time, a comprehensive analysis of their structure at both…

Astrophysics of Galaxies · Physics 2010-05-12 Jelte T. A. de Jong , Brian Yanny , Hans-Walter Rix , Andrew E. Dolphin , Nicolas F. Martin , Timothy C. Beers

We study the detailed properties of the radial metallicity gradient in the stellar disk of our Galaxy to constrain its chemical and structural evolution. For this purpose we select and analyze $\sim$ 18,500 disk stars taken from two…

Astrophysics of Galaxies · Physics 2015-06-19 Daisuke Toyouchi , Masashi Chiba

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…

Astrophysics of Galaxies · Physics 2017-11-20 Tuan Do , Wolfgang Kerzendorf , Nathan Winsor , Morten Støstad , Mark R. Morris , Jessica R. Lu , Andrea M. Ghez

The structure and kinematics of the recognized stellar components of the Milky Way are explored, based on well-determined atmospheric parameters and kinematic quantities for 32360 calibration stars from the Sloan Digital Sky Survey (SDSS)…