相关论文: Models of our Galaxy II
A leap forward has been performed due to the space-borne missions, MOST, CoRoT and Kepler. They provided a wealth of observational data, and more precisely oscillation spectra, which have been (and are still) exploited to infer the internal…
A three-component Stackel model of the Galaxy, including the bulge, disk, and halo, is constructed. Parameter estimates of the potential are obtained as a result of fitting the model rotation curve to azimuthal velocities found from data on…
We present a new method to construct fully self-consistent equilibrium models of multi-component disc galaxies similar to the Milky Way. We define distribution functions for the stellar disc and dark halo that depend on phase space position…
Stars in the Galactic disk are born on cold, nearly circular orbits with small vertical excursions. After their birth, their orbits evolve, driven by small- or large-scale perturbations in the Galactic disk's gravitational potential. Here,…
Minor bodies of the solar system can be used to measure the spectrum of the Sun as a star by observing sunlight reflected by their surfaces. To perform an accurate measurement of the radial velocity of the Sun as a star by this method, it…
We study the dynamical properties of halo stars located in the Solar Neighbourhood. Our goal is to explore how the properties of the halo depend on the selection criteria used for defining a sample of halo stars. Once this is understood we…
We present a method for measuring the Sun's motion using the proper motions of Galactic halo star streams. The method relies on the fact that the motion of the stars perpendicular to a stream from a low-mass progenitor is close to zero when…
Our knowledge of the Galaxy is being revolutionised by a series of photometric, spectroscopic and astrometric surveys. Already an enormous body of data is available from completed surveys, and data of ever increasing quality and richness…
Various types of inertial modes have been observed and identified on the Sun, including the equatorial Rossby modes, critical-latitude modes, and high-latitude modes. Recent observations further report a detection of…
Adiabatic modeling of solar-like oscillations cannot exceed a certain level of precision for fitting individual frequencies. This is known as the problem of near surface effects on the mode physics. We present a theoretical study which…
The nature of our Milky Way Galaxy is reexamined from an eclectic point of view. Evidence for a central bar, for example, is not reflected in the distribution of RR Lyrae variables in the central bulge [4,5], and it is not clear if either a…
Based on long baseline (5-7 years) multi-epoch HST/ACS photometry, used previously to measure the proper motion of M31, we present the proper motions (PMs) of 13 main-sequence Milky Way halo stars. The sample lies at an average distance of…
The kinematic properties of young stars that have not yet reached the stage of the main sequence are studied. The selection of these stars was recently carried out by Marton et al. (2019) and Vioque et al. (2020) according to the Gaia DR2…
The kinematics of distant OB stars perpendicular to the Galactic plane, inferred from proper motions in the Hipparcos catalogue, are analysed and compared to the kinematic signature that would be induced by a long-lived Galactic warp.…
The relative motion of stars and other celestial objects in very wide pairs, separated by distances of the order of 1 pc, is strongly influenced by the tidal gravitational potential of the Galaxy. The Coriolis component of the horizontal…
We homogeneously measured the elliptical shapes of 163 globular clusters (GCs) using the on-sky distribution of their cluster members and the third data release of the ESA mission Gaia (DR3). The astrometry enables the differentiation of…
Astrometric positions of moving objects in the Solar System have been measured using a variety of star catalogs in the past. Previous work has shown that systematic errors in star catalogs can affect the accuracy of astrometric…
We determine the total dynamical density in the solar neighbourhood using the Tycho-Gaia Astrometric Solution (TGAS) catalogue. Astrometric measurements of proper motion and parallax of stars inform us of both the stellar number density…
The rotation curve of the Galaxy is generally thought to be flat. However, using radial velocities from interstellar molecular clouds, which is common in rotation curve determination, seems to be incorrect and may lead to incorrectly…
We determine the mass of the Milky Way bar and the torque it causes, using Gaia DR2, by applying the orbital arc method. Based on this, we have found that the gravitational acceleration is not directed towards the centre of our Galaxy but a…