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Related papers: Weighing the Galactic disk using phase-space spira…

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We show how the combination of observations related to strong gravitational lensing and stellar dynamics in ellipticals offers a new way to measure the cosmological matter and dark-energy density parameters. A gravitational lensing estimate…

Astrophysics · Physics 2009-11-13 C. Grillo , M. Lombardi , G. Bertin

An accurate knowledge of the dark matter distribution in the Milky Way is of crucial importance for galaxy formation studies and current searches for particle dark matter. In this paper we set new dynamical constraints on the Galactic dark…

Astrophysics of Galaxies · Physics 2015-12-03 Miguel Pato , Fabio Iocco , Gianfranco Bertone

Gaia-DR2 has provided an unprecedented number of white dwarf candidates of our Galaxy. In particular, it is estimated that Gaia-DR2 has observed nearly 400,000 of these objects and close to 18,000 up to 100 pc from the Sun. This large…

Solar and Stellar Astrophysics · Physics 2019-03-27 S. Torres , C. Cantero , A. Rebassa-Mansergas , G. Skorobogatov , F. M. Jiménez-Esteban , E. Solano

The Gaia mission, with its unprecedented astrometric and photometric precision, combined with its Radial Velocity Spectrometer, will provide to the astronomical community a wealth of necessary constraints to disentangle between the…

Astrophysics of Galaxies · Physics 2012-09-28 G. Kordopatis

The dark matter halo of the Milky Way is expected to be triaxial and filled with substructure. It is hoped that streams or shells of stars produced by tidal disruption of stellar systems will provide precise measures of the gravitational…

Astrophysics of Galaxies · Physics 2015-06-19 Adrian M. Price-Whelan , David W. Hogg , Kathryn V. Johnston , David Hendel

Stellar kinematics provide a window into the gravitational field, and therefore into the distribution of all mass, including dark matter. Deep Potential is a method for determining the gravitational potential from a snapshot of stellar…

Astrophysics of Galaxies · Physics 2023-10-03 Taavet Kalda , Gregory M. Green , Soumavo Ghosh

A thin gaseous disk has often been investigated in the context of various phenomena in galaxies, which point to the existence of starburst rings and dense circumnuclear molecular disks. The effect of self-gravity of the gas in the 2D disk…

Mathematical Physics · Physics 2012-10-09 C. C. Yen , R. E. Taam , Ken H. C. Yeh , K. C. Chang

We use the second data releases of the ESA Gaia astrometric survey and the high-resolution GALAH spectroscopic survey to analyse the structure of our Galaxy's disc components. With GALAH, we separate the alpha-rich and alpha-poor discs…

Several works have recently applied Jeans modelling to Gaia-based datasets to infer the circular velocity curve for the Milky Way. Such works have consistently found evidence for a continuous decline in the rotation curve beyond $\sim$15kpc…

Astrophysics of Galaxies · Physics 2024-12-04 Orlin Koop , Teresa Antoja , Amina Helmi , Thomas M. Callingham , Chervin F. P. Laporte

Perturbations to stellar systems can reflect the gravitational influence of dark matter substructures. On scales much smaller than the size of a stellar system, we point out analytic connections between the stellar and dark matter…

Astrophysics of Galaxies · Physics 2024-03-21 M. Sten Delos

It is of great interest to measure the properties of substructures in dark matter halos at galactic and cluster scales. Here we suggest a method to constrain substructure properties using the variance of weak gravitational flexion in a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 D. J. Bacon , A. Amara , J. I. Read

We investigate gravitational lensing by a realistic model of disk galaxies. Most of the mass is contained in a large spherical isothermal dark matter halo, but the potential is modified significantly in the core by a…

Astrophysics · Physics 2009-10-30 Ole Moeller , A. W. Blain

Over the course of several years, stars trace helical trajectories as they traverse across the sky due to the combined effects of proper motion and parallax. It is well known that the gravitational pull of an unseen companion can cause…

Solar and Stellar Astrophysics · Physics 2023-07-05 Jeff J. Andrews , Katelyn Breivik , Chirag Chawla , Carl Rodriguez , Sourav Chatterjee

We report a significant detection of weak, tangential distortion of the images of cosmologically distant, faint galaxies due to gravitational lensing by foreground galaxies. A mean image polarisation of $<p>=0.011\pm 0.006$ is measured for…

Astrophysics · Physics 2016-08-30 Tereasa Brainerd , Roger Blandford , Ian Smail

The mean Galactocentric radial velocities $\langle v_{R}\rangle(R,\varphi)$ of luminous red giant stars within the mid-plane of the Milky Way reveal a spiral signature, which could plausibly reflect the response to a non-axisymmetric…

We used 1627 faint (15.5< R<23) stars in five fields of the Calar Alto Deep Imaging Survey (CADIS) to estimate the structure parameters of the Galaxy. The results were derived by applying two complementary methods: first by fitting the…

Astrophysics · Physics 2009-11-11 S. Phleps , S. Drepper , K. Meisenheimer , B. Fuchs

Aims: To study the imprints of a rotating bar on the kinematics of stars in the thin and thick disks throughout the Galaxy. Methods: We perform test particle numerical simulations of the thin and thick disks in a 3D Galactic potential that…

Astrophysics of Galaxies · Physics 2013-11-25 Giacomo Monari , Teresa Antoja , Amina Helmi

Context. The astrometric satellite Gaia is expected to significantly increase our knowledge as to the properties of the Milky Way. The Gaia Early Data Release 3 (Gaia EDR3) provides the most precise parallaxes for many OB stars, which can…

Astrophysics of Galaxies · Physics 2021-01-20 Y. Xu , L. G. Hou , S. B. Bian , C. J. Hao , D. J. Liu , J. J. Li , Y. J. Li

There are few warp kinematic models of the Galaxy able to characterise structure and kinematics. These models are necessary to study the lopsidedness of the warp and the twisting of the line-of-nodes of the stellar warp, already seen in gas…

Astrophysics of Galaxies · Physics 2019-07-17 M. Romero-Gómez , C. Mateu , L. Aguilar , F. Figueras , A. Castro-Ginard

I describe how the dynamics of galactic disks can be inferred by imaging and spectroscopy. Next I demonstrate that the decomposition of the rotation curves of spiral galaxies into the contributions by the various components of the galaxies…

Astrophysics · Physics 2009-11-13 B. Fuchs