2014/02/28 by Giacomo Monari, G. Monari, Amina Helmi +5 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Bar (unit) #Disc #Galactic Center #Galactic tide #Milky Way #Radial velocity #Scale height #Scientific Research and Discoveries #Stars #Stellar, planetary, and galactic studies #Test particle #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201423666
published as A&A 569, A69 (2014) · 9 pages, 11 figures, v2. Accepted for publication on A&A
openalex publication_date 2014/08/04 · arxiv created 2014/08/05 · arxiv updated 2014/10/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate whether the cylindrical (galactocentric) radial velocity gradient of ~ −3 km s-1 kpc-1, directed radially from the Galactic center and recently observed in the stars of the solar neighborhood with the RAVE survey, can be explained by the resonant effects of the bar near the solar neighborhood. We compared the results of test particle simulations of the Milky Way with a potential that includes a rotating bar with observations from the RAVE survey. To this end we applied the RAVE selection function to the simulations and convolved these with the characteristic RAVE errors. We explored different “solar neighborhoods” in the simulations, as well as different bar models. We find that the bar induces a negative radial velocity gradient at every height from the Galactic plane, outside the outer Lindblad resonance and for angles from the long axis of the bar compatible with the current estimates. The selection function and errors do not wash away the gradient, but often make it steeper, especially near the Galactic plane, because this is where the RAVE survey is less radially extended. No gradient in the vertical velocity is present in our simulations, from which we may conclude that this cannot be induced by the bar.