On the possible generation of the young massive open clusters Stephenson2 and BDSB122 by Omega Centauri

TL;DR

This study investigates whether the passage of the massive globular cluster Omega Centauri through the galactic disk could have triggered the formation of the young massive open clusters Stephenson 2 and BDSB 122 by analyzing their orbital histories.

Contribution

It provides a novel orbital analysis linking Omega Centauri's disk crossing to the potential formation sites of specific young open clusters, suggesting globular clusters as progenitors.

Findings

Orbit analysis shows consistency between Omega Centauri's impact site and cluster birthplaces.

Timing of Omega Centauri's disk crossing aligns with the formation ages of the open clusters.

Results support the hypothesis that globular clusters can trigger open cluster formation.

Abstract

A massive objects such as a globular cluster passing through the disk of a galaxy can trigger star formation. We test the hypothesis that the most massive globular cluster in the Galaxy, $\omega$ Centauri, which crossed the disk approximately $24\pm2$ Myr ago, may have triggered the formation of the open clusters Stephenson 2 and BDSB 122. The orbits of $\omega$ Centauri, Stephenson 2 and BDSB 122 are computed for the three-component model of Johnston, Hernquist & Bolte, which considers the disk, spheroidal and halo gravitational potentials. With the re-constructed orbit of $\omega$ Centauri, we show that the latest impact site is consistent, within important uncertainties, with the birth-site of the young massive open clusters BDSB 122 and Stephenson 2. Within uncertainties, this scenario is consistent with the time-scale of their backwards motion in the disk, shock wave propagation and delay for star formation. Together with open cluster formation associated to density waves in spiral arms, the present results are consistent with the idea that massive globular clusters as additional progenitors of open clusters, the massive ones in particular.