We report that the gas components in the N59 bubble suffered from sequential multiple cloud-cloud collision (CCC) processes. The molecular gas in the N59 bubble can be decomposed into four velocity components, namely Cloud A [95, 108] km s−1, Cloud B [86, 95] km s−1, Cloud C [79, 86] km s−1 and Cloud D [65, 79] km s−1. Four CCC processes occurred among these four velocity components, i.e., Cloud A vs. Cloud B, Cloud A vs. Cloud C, Cloud C vs. Cloud D, and Cloud A vs. Cloud D. Using Spitzer MIR and UKIDSS NIR photometric point source catalogs, we identified 514 YSO candidates clustered in 13 YSO groups, and most of them (~60%) were located at the colliding interfaces, indicating that they were mainly triggered by these four CCC processes. We also found that these four collisions occurred in a time sequential order: the earliest and most violent collision occurred between Cloud A and Cloud D about 2 Myr ago, then Cloud B collided with Cloud A about 1 Myr ago, and finally, Cloud C collided with Clouds A and D simultaneously about 0.4 Myr ago.
Cite
@article{arxiv.2410.13742,
title = {Multiple collisions in N59 bubble: Sequential cloud-cloud collisions},
author = {En Chen and Xi Chen and Xuepeng Chen and Min Fang and Qianru He},
journal= {arXiv preprint arXiv:2410.13742},
year = {2024}
}