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

Anna Melnik, Ekaterina Podzolkova

arXiv:2409.17094v1 Announce Type: new

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 theta_01, theta_02 and theta_03 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

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 theta_01, theta_02 and theta_03 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

2024-09-26