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Related papers: Radial velocities in the outermost disk toward the…

200 papers

A detailed measurement is made of the metallicity distributions, kinematics and dynamics of the thin and thick disks, across a large disk volume (5.0 $\leq$ $R$ $\leq$ 15.0 kpc and $|Z|$ $\leq$3.0 kpc), by using the LAMOST-APOGEE red clump…

Astrophysics of Galaxies · Physics 2024-03-20 Weixiang Sun , Han Shen , Biwei Jiang , Xiaowei Liu

We analyse a controlled N-body + smoothed particle hydrodynamics simulation of a growing disc galaxy within a non-growing, live dark halo. The disc is continuously fed with gas and star particles on near-circular orbits and develops a bar…

Astrophysics of Galaxies · Physics 2015-10-06 Michael Aumer , Ralph Schönrich

Non-axisymmetric components, such as spirals and central bars, play a major role in shaping galactic discs. An important aspect of the disc secular evolution driven by these perturbers is the radial migration of stars. It has been suggested…

Astrophysics of Galaxies · Physics 2015-06-05 I. Minchev , B. Famaey , A. C. Quillen , W. Dehnen , M. Martig , A. Siebert

Radial velocity is one of key measurements in understanding the fundamental properties of stars, stellar clusters and the Galaxy. A plate of stars in the Kepler field were observed in May of 2018 with the medium-resolution spectrographs of…

Using a sample of 31 main-sequence OB stars located between galactocentric distances 8.4 - 15.6 kpc, we aim to probe the present-day radial abundance gradients of the Galactic disk. The analysis is based on high-resolution spectra obtained…

Solar and Stellar Astrophysics · Physics 2019-05-29 G. A. Braganca , S. Daflon , T. Lanz , K. Cunha , T. Bensby , P. J. McMillan , C. D. Garmany , J. W. Glaspey , M. Borges Fernandes , M. S. Oey , I. Hubeny

Using available kinematical data for a subsample of NLTT stars from the HIPPARCOS mission we confirm the existence of a previously reported local anomaly in the (u,v) plane: the mean motion u for old disc stars, with v < -30 km/s, is…

Astrophysics · Physics 2007-05-23 D. Raboud , M. Grenon , L. Martinet , R. Fux , S. Udry

We created and are constantly updating the Orion Spiral Arm CAtalogue (OSACA) for stars with known coordinates, parallaxes, proper motions and radial velocities. It is shown that there is an effect of contraction appearing in motion of…

Astrophysics · Physics 2009-11-11 Vadim V. Bobylev , Anisa T. Bajkova , George A. Gontcharov

The radial distance to the co-rotation radius Rcoro (where the angular speed of the gas and stars in orbit around the Galactic Centre is equal to the angular speed of the spiral arm pattern) has often been predicted (at various places), but…

Astrophysics of Galaxies · Physics 2018-08-15 Jacques P Vallee

This work presents the results from extending the long-term monitoring program of stellar motions within the Galactic Center to include stars with separations of 2 - 7 arcseconds from the compact radio source, Sgr A*. In comparison to the…

We study the kinematics of the Galactic thin and thick disk populations using stars from the RAVE survey's second data release together with distance estimates from Breddels et al. (2009). The velocity distribution exhibits the expected…

Astrophysics of Galaxies · Physics 2015-05-27 Yüksel Karatas , Rainer J. Klement

We explore the correlations between velocity and metallicity and the possible distinct chemical signatures of the velocity over-densities of the local Galactic neighbourhood. We use the large spectroscopic survey RAVE and the Geneva…

Open star clusters from the MWSC (Milky Way Star Clusters) catalogue have been used to determine the Galactic rotation parameters. The circular rotation velocity of the solar neighborhood around the Galactic center has been found from data…

Astrophysics of Galaxies · Physics 2016-09-30 V. V. Bobylev , A. T. Bajkova , K. S. Shirokova

To study the peculiarities of the Galactic spiral density wave, we have analyzed the space velocities of Galactic Cepheids with proper motions from the Hipparcos catalog and line-of-sight velocities from various sources. First, based on the…

Astrophysics of Galaxies · Physics 2012-12-20 V. V. Bobylev , A. T. Bajkova

We consider a differentially rotating, 2D stellar disk perturbed by two steady state spiral density waves moving at different patterns speeds. Our investigation is based on direct numerical integration of initially circular test-particle…

Chaotic Dynamics · Physics 2007-05-23 I. Minchev , A. C. Quillen

High-velocity stars are interesting targets to unveil the formation of the Milky Way. In fact they can be recently accreted from an infalling dwarf galaxies or they can be the result of a turbulent merging of galaxies. Gaia is providing the…

We have tested the method of determining the solar Galactocentric distance R_0 and Galactic rotation velocity $V_0$ modified by Sofue et al. using near-solar-circle objects. The motion of objects relative to the local standard of rest has…

Astrophysics of Galaxies · Physics 2013-01-01 V. V. Bobylev

In the solar-neighbourhood, older stars have larger random velocities than younger ones. It is argued that the increase in velocity dispersion with time is predominantly a gradual process rather than one induced by discrete events such as…

Astrophysics · Physics 2007-05-23 James Binney

Nearly 400 Tycho-2 stars have been observed in a 720 square degree field in the direction of the North Galactic Pole with the high resolution echelle spectrograph ELODIE. Absolute magnitudes, effective temperatures, gravities and…

Astrophysics · Physics 2009-11-07 C. Soubiran , O. Bienaymé , A. Siebert

The stellar velocity ellipsoid of the solar neighbour is re-examined using intermediate-old mono-abundances stellar groups with high quality chemistry data together with parallaxes and proper motions from Gaia DR1. We find the average…

Astrophysics of Galaxies · Physics 2017-12-20 Borja Anguiano , Steven R. Majewski , Kenneth C. Freeman , Arik W. Mitschang , Martin C. Smith