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Related papers: Refining the Oort and Galactic constants

200 papers

The Galactic bulge and bar are critical to our understanding of the Milky Way. However, due to the lack of reliable stellar distances, the structure and kinematics of the bulge/bar beyond the Galactic center have remained largely…

This work explores dynamical models of the Milky Way (MW) by analyzing a sample of 86,109 K giant stars selected through cross-matching the LAMOST DR8 and Gaia EDR3 surveys. Our earlier torus models in Wang et al. (2017) did not include…

Astrophysics of Galaxies · Physics 2025-05-26 Guang-Chen Sun , Qiao Wang , Shude Mao , Yichao Li , Richard J. Long , Ping-Jie Ding , Yougang Wang , Xin Zhang , Xuelei Chen

A simple one-dimensional axisymmetric disc model is applied to the kinematics of OB stars near the Sun obtained from Gaia DR3 catalogue. The model determines the 'local centrifugal speed' $V_\mathrm{c}(R_{0})$ - defined as the circular…

Astrophysics of Galaxies · Physics 2023-10-11 Aisha S. Almannaei , Daisuke Kawata , Junichi Baba , Jason A. S. Hunt , George Seabroke , Ziyang Yan

We use an $N$-body+smoothed particle hydrodynamics simulation of an isolated barred galaxy to study the age dependence of bulge longitudinal proper motion ($\mu_l$) rotation curves. We show that close to the minor axis ($|l| \sim 0^\circ$)…

Demers and Battinelli published, in 2007 the rotation curve of the Milky Way based on the radial velocity of carbon stars outside the Solar circle. Since then we have established a new list of candidates for spectroscopy. The goal of this…

Solar and Stellar Astrophysics · Physics 2015-06-12 P. Battinelli , S. Demers , C. Rossi , K. S. Gigoyan

To illustrate the potential of GDR2, we provide a first look at the kinematics of the Milky Way disc, within a radius of several kiloparsecs around the Sun. We benefit for the first time from a sample of 6.4 million F-G-K stars with full 6D…

Based on published data, we have collected information about Galactic maser sources with measured distances. In particular, 44 Galactic maser sources located in star-forming regions have trigonometric parallaxes, proper motions, and radial…

Astrophysics of Galaxies · Physics 2013-02-07 A. S. Stepanishchev , V. V. Bobylev

In the present paper, we aim to determine the kinematical properties, velocity ellipsoid, and Oort constants using a sample of halo red giants. The study is based mainly on the space and radial velocities of about 1583 red giant stars…

Solar and Stellar Astrophysics · Physics 2020-06-17 Mohamed I. Nouh , Waleed H. Elsanhoury

Until the recent advent of $Gaia$ Data Release 2 (DR2) and deep multi-object spectroscopy, it has been difficult to obtain 6-D phase space information for large numbers of stars beyond 4 kpc, in particular towards the Galactic centre, where…

We report new precision measurements of the properties of our Galaxy's supermassive black hole. Based on astrometric (1995-2007) and radial velocity (2000-2007) measurements from the W. M. Keck 10-meter telescopes, a fully unconstrained…

After their initial formation, disk galaxies are observed to be rotationally stable over periods of >6 Gyr, implying that any large velocity disturbances of stars and gas clouds are damped rapidly on the timescale of their rotation.…

Astrophysics of Galaxies · Physics 2022-11-08 John Herbert Marr

In the past several years high resolution kinematic data sets from Milky Way satellite galaxies have confirmed earlier indications that these systems are dark matter dominated objects. Further understanding of what these galaxies reveal…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Louis E. Strigari

Under the assumption of a simple and time-invariant gravitational potential, many Galactic dynamics techniques infer the Milky Way's mass and dark matter distribution from stellar kinematic observations. These methods typically rely on…

We present a kinematical study of the outer halo (r_GC approximately 60 to 160 kpc) of the Milky Way based on spectroscopy of 55 RR Lyrae stars obtained with the ESI instrument on the Keck II telescope. Our spectroscopic targets were…

The distribution of shapes of galaxies' dark halos provides a basic test for models of galaxy formation. To-date, few dark halo shapes have been measured, and the results of different methods appear contradictory. Here, we add to the sample…

Astrophysics · Physics 2007-05-23 R. P. Olling , M. R. Merrifield

We tentatively look at anthropic constraints on the Cosmological Constant (CC) \Lambda at galactic scales by investigating its influence on the motion of the Sun throughout the Milky Way (MW) for -4.5 <= t <=0 Gyr. In particular, we look at…

General Relativity and Quantum Cosmology · Physics 2010-04-08 Lorenzo Iorio

We analyze the three-dimensional kinematics of about 82000 Tycho-2 stars belonging to the red giant clump (RGC). First, based on all of the currently available data, we have determined new, most probable components of the residual rotation…

Astrophysics of Galaxies · Physics 2010-08-26 Vadim V. Bobylev

Flat rotation curves in disk galaxies represent the main evidence for large amounts of surrounding dark matter. Despite of the difficulty in identifying the dark matter contribution to the total mass density in our Galaxy, stellar…

Astrophysics of Galaxies · Physics 2020-06-15 Mariateresa Crosta , Marco Giammaria , Mario G. Lattanzi , Eloisa Poggio

The frequency of Galactic stellar encounters the Solar system experienced depends on the local density and velocity dispersion along the orbit of the Sun in the Milky Way galaxy. We aim at determining the effect of the radial migration of…

Earth and Planetary Astrophysics · Physics 2016-10-12 C. A. Martínez-Barbosa , L. Jílková , S. Portegies Zwart , A. G. A. Brown

We construct a dynamical model of the Milky Way disk from a data set, which combines Gaia EDR3 and APOGEE data throughout Galactocentric radii between $5.0\leq R\leq19.5$ kpc. We make use of the spherically-aligned Jeans Anisotropic Method…

Astrophysics of Galaxies · Physics 2021-08-05 Maria Selina Nitschai , Anna-Christina Eilers , Nadine Neumayer , Michele Cappellari , Hans-Walter Rix