Results 81 to 90 of about 40,578 (188)

Modeling the Radial Distribution of Pulsars in the Galaxy

open access: yesThe Astrophysical Journal Letters
The Parkes 20 cm multibeam pulsar surveys have discovered nearly half of the known pulsars and revealed many distant pulsars with high dispersion measures.
J. T. Xie   +4 more
doaj   +1 more source

Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. VIII. Mapping the Kinematics of the Galactic Disk Using Mono-age and Mono-abundance Stellar Populations

open access: yesThe Astrophysical Journal
We present a comprehensive study of the kinematic properties of the different Galactic disk populations, as defined by the chemical abundance ratios and stellar ages, across a large disk volume (4.5 ≤ R ≤ 15.0 kpc and ∣ Z ∣ ≤ 3.0 kpc), by using the ...
Weixiang Sun   +7 more
doaj   +1 more source

Metallicity and α-abundance for 48 Million Stars in Low-extinction Regions in the Milky Way

open access: yesThe Astrophysical Journal
We estimate ([M/H], [ α /M]) for 48 million giants and dwarfs in low-dust extinction regions from the Gaia DR3 XP spectra by using tree-based machine learning models trained on APOGEE DR17 and a metal-poor star sample from Li et al.
Kohei Hattori
doaj   +1 more source

Are dSph galaxies Galactic building blocks?

open access: yesEPJ Web of Conferences, 2012
Dwarf spheroidal galaxies (dSph) are frequently assumed to represent surviving examples of a vast now destroyed population of small systems in which many of the stars now forming the Milky Way were formed. Ongoing accretion and considerable sub-structure
Gilmore G., Asiri H.M.
doaj   +1 more source

Accurate, Precise, and Physically Self-consistent Ages and Metallicities for 400,000 Solar Neighborhood Subgiant Branch Stars

open access: yesThe Astrophysical Journal
Age is the most difficult fundamental stellar parameter to infer for isolated stars. While isochrone-based ages are in general imprecise for both main-sequence dwarfs and red giants, precise isochrone-based ages can be obtained for stars on the subgiant ...
David M. Nataf   +3 more
doaj   +1 more source

Rotation of galaxies and dark matter

open access: yesResults in Physics, 2023
In a previous paper by the author was proposed a new metric for the gravitational field of a thin rotating disk physically different from the Kerr metric. The metric is admissible for any angular momentum of the disk. As demonstrated in the present paper
V.A. Golovko
doaj  

Rising from the Ashes: A Metallicity-dependent Star Formation Gap Splits the Milky Way’s α Sequences

open access: yesThe Astrophysical Journal
The elemental abundance distribution of stars encodes the history of the gas-phase abundance in the Milky Way. Without a large, unbiased sample of highly precise stellar ages, the exact timing and nature of this history must be inferred from the ...
Angus Beane
doaj   +1 more source

Using frequency maps to explore the distribution function of the Milky Way stellar halo

open access: yesEPJ Web of Conferences, 2012
Resolved surveys of the Milky Way's stellar halo can obtain all 6 phase space coordinates of tens of thousands of individual stars, making it possible to compute their 3-dimensional orbits.
Valluri M.
doaj   +1 more source

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