3-D kinematics of classical Cepheids according to Gaia, EDR3 catalog
| Autor: | Bobylev, V. V., Bajkova, A. T. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1674-4527/acb878 |
| Popis: | The kinematics of about 2000 classical Cepheids of the Milky Way with data from Gaia\,EDR3 catalog has been studied. For some of these stars, there are line-of-sight velocities. On the basis of the nonlinear rotation model, the parameters of the rotation curve of the Galaxy were determined. The circular linear rotation velocity of the near-solar neighborhood around the Galaxy center was $V_0=236\pm 3$~km s$^{-1}$ for the assumed Sun's galactocentric distance $R_0=8.1\pm0.1$~kpc. Analysis of residual velocities of Cepheids based on the linear Ogorodnikov-Milne model showed the presence of the following significantly different from zero gradients: $\partial U/\partial x,$ $\partial U/\partial z,$ $\partial V/\partial x,$ $\partial V/\partial z$ and $\partial W/\partial x,$ which behaves differently depending on the selection radius. The most interesting is the gradient $\partial W/\partial x\sim-0.5\pm0.1$~km s$^{-1}$ kpc$^{-1}$ (positive rotation of this star system around the galactic axis $y$, $\Omega_y$) since the velocities $W$ are free of galactic rotation. Here we have an indirect influence of various effects leading to a perturbation of the vertical velocities of the galactic disk stars. Based on a simpler model, a more accurate estimate of this rotation is obtained, $\Omega_y=0.51\pm0.07$~km s$^{-1}$ kpc$^{-1}$. Comment: 20 pages, 4 figures, 3 tables. Accepted to be published in Research in Astronomy and Astrophysics |
| Databáze: | arXiv |
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