Humps on the profiles of the radial-velocity distribution and the age of the Galactic bar

2024/09/25 by A. M. Melnik, Melnik, Anna, E. N. Podzolkova +1
Earth and Planetary Sciences · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Geophysics and Gravity Measurements #Stellar, planetary, and galactic studies

paper · pdf · doi:10.48550/arxiv.2409.17094

openalex publication_date 2024/09/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We studied the model of the Galaxy with a bar which reproduces well the distributions of the observed radial, VR, and azimuthal, VT, velocities derived from the Gaia DR3 data along the Galactocentric distance R. The model profiles of the distributions of the velocity VR demonstrate a periodic increase and the formation of a hump (elevation) in the distance range of 6--7 kpc. The average amplitude and period of variations in the velocity VR are A=1.76 +/- 0.15 km s-1 and P=2.1 +/- 0.1 Gyr. We calculated angles theta₀1, theta₀2 and theta₀3 which determine orientations of orbits relative to the major axis of the bar at the time intervals: 0--1, 1--2 and 2--3 Gyr from the start of simulation. Stars whose orbits change orientations as follows: 0

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