Age Estimation of the Radcliffe Wave from Open Star Clusters

Abstract

Four samples of open star clusters (OSCs) with average ages of 5.2, 18.6, 40, and 61 Myr have been analyzed. The selection of these OSCs was carried out from a narrow region inclined to the galactic axis y at an angle of 25$^\circ$. The spectral analysis of the vertical positions and velocities of the selected clusters showed that the Radcliffe wave is associated with OSCs no older than 30 Myr. The following estimates of the Radcliffe wave characteristics were obtained for the OSCs with an average age of 5.2 Myr: $z_{max}=117\pm12$ pc with the wavelength $\lambda=4.55\pm0.14$ kpc, the vertical velocity disturbance amplitude $W_{max}=4.86\pm0.19$ km s$^{-1}$ with the wavelength $\lambda=1.74\pm0.08$ kpc. For the OSCs with an average age of 18.6 Myr, the estimates are as follows: $z_{max} = 54\pm5$ pc and $\lambda=6.30\pm0.12$ kpc, the vertical velocity disturbance amplitude $W_{max}=7.90\pm0.16$ km s$^{-1}$ and $\lambda=0.83\pm0.11$ kpc. The radial motion of the Radcliffe wave away from the galactic center has been confirmed. The velocity of such movement is 10 pc Myr$^{-1}$. In our opinion, the spatial distribution of OSCs younger than 30 Myr does not contradict the hypothesis of the association of the Radcliffe wave with the impact of shock waves from supernova explosions that arose on an extended front comparable in scale to the entire wave, that is, about 2 kpc in size.