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相关论文: Metallicity Gradients of Thick Disk Dwarf Stars

200 篇论文

We probe the stellar population age and metallicity distributions in nearby elliptical galaxies over the largest extension to date. Long-slit spectroscopy is made by using the spectrograph SCORPIO of the 6-m telescope of the Special…

天体物理学 · 物理学 2009-11-13 M. Baes , O. K. Sil'chenko , A. V. Moiseev , E. A. Manakova

We present evidence that there is an M dwarf problem similar to the previously identified G dwarf and K dwarf problems: the number of low-metallicity M dwarfs is not sufficient to match simple closed-box models of local Galactic chemical…

太阳与恒星天体物理 · 物理学 2015-06-04 Vincent M. Woolf , Andrew A. West

(Abridged) We analyze chemical and kinematical properties of about 850 FGK solar neighborhood long-lived dwarfs observed with the HARPS high-resolution spectrograph. The stars in the sample have logg > 4 dex, 5000 < Teff < 6500 K, and -1.39…

The analysis of the kinematics of solar neighbourhood stars shows that the low and high metallicity tails of the thin disc are populated by objects which orbital properties suggest an origin in the outer and inner galactic disc,…

天体物理学 · 物理学 2009-11-13 Misha Haywood

(Abridged) We have used the atmospheric parameters, [alpha/Fe] abundances and radial velocities, determined from the Gaia-ESO Survey GIRAFFE spectra of FGK-type stars (iDR1), to provide a chemo-kinematical characterisation of the disc…

The behavior of the relative magnesium abundances in the thin-disk stars versus their orbital radii suggests that the star formation rate in the thin disk decreases with increasing Galactocentric distance, and there was no star formation…

天体物理学 · 物理学 2007-10-29 V. A. Marsakov , M. V. Shapovalov , T. V. Borkova

Around 16% of the solar-like stars in our neighbourhood show IR-excesses due to debris discs and a fraction of them are known to host planets. We aim to determine in a homogeneous way the metallicity of a sample of stars with known debris…

地球与行星天体物理 · 物理学 2015-06-04 J. Maldonado , C. Eiroa , E. Villaver , B. Montesinos , A. Mora

The study of radial metallicity gradients in the disc of the Milky Way is a powerful tool to understand the mechanisms that have been acting in the formation and evolution of the Galactic disc. In this proceeding, I will put the eye on some…

星系天体物理 · 物理学 2020-03-04 Jorge García-Rojas

We present the results of radial velocity measurements of 770 thick disk red giants toward the South Galactic Pole, vertically distributed from 0.5 kpc to 5 kpc with respect to the Galactic plane. We find a small gradient in the vertical…

We present integral field spectroscopy observations of two star-forming dwarf galaxies in the Virgo cluster (VCC135 and VCC324) obtained with PMAS/PPak at the Calar Alto 3.5 meter telescope. We derive metallicity maps using the N2 empirical…

Radial metallicity trends provide a key indicator of physical processes such as star formation and radial gas migration within a galaxy. Large IFU surveys allow for detailed studies of these radial variations, with recent observations…

星系天体物理 · 物理学 2022-01-19 Bethan Easeman , Patricia Schady , Stijn Wuyts , Robert M. Yates

Stars with planets at intermediate metallicities ([-0.7,-0.2] dex) exhibit properties that differ from the general field stars. Thirteen stars with planets reported in this metallicity range belong to the thick disc, while only one planet…

天体物理学 · 物理学 2009-11-13 Misha Haywood

We study dwarf galaxies in the Centaurus A group to investigate their metallicity and possible environmental effects. The Centaurus A group (at ~4 Mpc from the Milky Way) contains about 50 known dwarf companions of different morphologies…

宇宙学与河外天体物理 · 物理学 2015-05-18 D. Crnojević , E. K. Grebel , A. Koch

The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open clusters allow us to derive both the radial metallicity distribution and its evolution over time.…

By using images from the HST/WFPC2/ACS archive, we have analyzed the spatial distribution of the AGB and RGB stars along the galactocentric radius of nearby spiral galaxies M~81, NGC 300 and NGC 55. Using color-magnitude diagrams and…

天体物理学 · 物理学 2009-11-10 N. A. Tikhonov , O. A. Galazutdinova , I. O. Drozdovsky

In this paper, we present low resolution (R=500) near-infrared spectra for selected and serendipitous sources in six inner in-plane Galactic fields, with the aim of analysing the stellar content present. From the equivalent widths of the…

天体物理学 · 物理学 2009-11-13 C. González-Fernández , A. Cabrera-Lavers , P. L. Hammersley , F. Garzón

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…

Elliptical galaxies probably host the most metal rich stellar populations in the Universe. The processes leading to both the formation and the evolution of such stars are discussed by means of a new multi-zone photo-chemical evolution…

天体物理学 · 物理学 2007-05-23 Antonio Pipino , Francesca Matteucci