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Related papers: Machine Learning the 6th Dimension: Stellar Radial…

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Context. The Gaia mission has opened up a new era for the precise astrometry of stars, thus revolutionizing our understanding of the Milky Way. However, beyond a few kiloparseconds from the Sun, parallax measurements become less reliable,…

Solar and Stellar Astrophysics · Physics 2024-10-16 Yue-Yue Shen , A-Li Luo

This paper reports on the application of the supervised machine-learning algorithm to the stellar effective temperature regression for the second $Gaia$ data release, based on the combination of the stars in four spectroscopic surveys:…

Solar and Stellar Astrophysics · Physics 2019-08-14 Yu Bai , JiFeng Liu , ZhongRui Bai , Song Wang , DongWei Fan

Combined studies of variable stars and stellar clusters open great horizons, and they allow us to improve our understanding of stellar cluster formation and stellar evolution. In that prospect, the Gaia mission will provide astrometric,…

The velocity distribution of stars in the Solar neighbourhood is inhomogeneous and rich with stellar streams and kinematic structures. These may retain important clues of the formation and dynamical history of the Milky Way. However, the…

Astrophysics of Galaxies · Physics 2017-12-13 Iryna Kushniruk , Thiebaut Schirmer , Thomas Bensby

Machine learning has increasingly gained more popularity with its incredibly powerful ability to make predictions or calculated suggestions for large amounts of data. We apply the machine learning classification to 85,613,922 objects in the…

Solar and Stellar Astrophysics · Physics 2018-10-17 Yu Bai , JiFeng Liu , Song Wang

The Gaia mission has provided the largest ever astrometric chart of the Milky Way. Using it to map the Galactic halo is helpful for disentangling its merger history. The identification of halo stars in Gaia DR2 with reliable distance…

Astrophysics of Galaxies · Physics 2021-11-25 Helmer H. Koppelman , Amina Helmi

Gaia DR2 5932173855446728064 was recently proposed to be unbound from the Milky Way based on the $-614.3\pm2.5\;\mathrm{km}\;\mathrm{s}^{-1}$ median radial velocity given in Gaia DR2. We obtained eight epochs of spectroscopic follow-up and…

We measure the three components of velocity dispersion, $\sigma_{R},\sigma_{\theta},\sigma_{\phi}$, for stars within 6 < R < 30 kpc of the Milky Way using a new radial velocity sample from the MMT telescope. We combine our measurements with…

Astrophysics of Galaxies · Physics 2015-11-11 Charles King , Warren R. Brown , Margaret J. Geller , Scott J. Kenyon

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

Spectrograph aboard the GAIA satellite operates in the near-IR, in the 8490-- 8740 \AA window accessible also from the ground. The most important parameter yet to be determined is the spectral resolution. Realistic estimates of the zodiacal…

Astrophysics · Physics 2009-11-07 Tomaz Zwitter

The stellar velocity distribution function (DF) in the solar vicinity is re-examined using data from the SDSS APOGEE survey's DR16 and \emph{Gaia} DR2. By exploiting APOGEE's ability to chemically discriminate with great reliability the…

Precise Gaia measurements of positions, parallaxes, and proper motions provide an opportunity to calculate 3D positions and 2D velocities (i.e. 5D phase-space) of Milky Way stars. Where available, spectroscopic radial velocity (RV)…

Astrophysics of Galaxies · Physics 2022-07-06 Ruth Angus , Adrian M. Price-Whelan , Joel C. Zinn , Megan Bedell , Yuxi , Lu , Daniel Foreman-Mackey

This work presents the results of a kinematic analysis of the Galaxy that uses a new model as applied to the newest available Gaia data. We carry out the Taylor decomposition of the velocity field up to second order for 18 million high…

Astrophysics of Galaxies · Physics 2024-03-29 V. S. Akhmetov , B. Bucciarelli , M. Crosta , M. G. Lattanzi , A. Spagna , P. Re Fiorentin , E. Yu. Bannikova

Under certain conditions, stellar radial velocities can be determined from astrometry, without any use of spectroscopy. This enables us to identify phenomena, other than the Doppler effect, that are displacing spectral lines. The change of…

Solar and Stellar Astrophysics · Physics 2021-08-18 Lennart Lindegren , Dainis Dravins

Stellar rotation influences our understanding of stellar structure and evolution, binary systems, clusters etc. and therefore the benefits of a large and highly accurate database on stellar rotation, obtained by GAIA, will be manifold. To…

Astrophysics · Physics 2007-05-23 Andreja Gomboc

Gaia's Radial Velocity Spectrometer (RVS) has been operating in routine phase for over one year since initial commissioning. RVS continues to work well but the higher than expected levels of straylight reduce the limiting magnitude. The…

We have mapped the number density and mean vertical velocity of the Milky Way's stellar disk out to roughly two kiloparsecs from the Sun using Gaia Data Release 3 (DR3) and complementary photo-astrometric distance information from…

Astrophysics of Galaxies · Physics 2022-12-14 Axel Widmark , Lawrence M. Widrow , Aneesh Naik

We continue our series of papers on phase-space distributions of stars in the Milky Way based on photometrically derived metallicities and Gaia astrometry, with a focus on the halo-disk interface in the local volume. To exploit various…

Astrophysics of Galaxies · Physics 2023-07-26 Deokkeun An , Timothy C. Beers , Young Sun Lee , Thomas Masseron

The Gaia era opens new possibilities for discovering the remnants of disrupted satellite galaxies in the Solar neighborhood. If the population of local accreted stars is correlated with the dark matter sourced by the same mergers, one can…

In the coming decade the Gaia satellite will precisely measure the positions and velocities of millions of stars in the Galactic halo, including stars in many tidal streams. These streams, the products of hierarchical accretion of satellite…

Astrophysics of Galaxies · Physics 2016-02-17 Robyn E. Sanderson