One, Two, Three ... An Explosive Outflow in IRAS 12326-6245 Revealed by ALMA

Abstract

In the last years there has been a substantial increase in the number of the reported massive and luminous star-forming regions with related explosive outflows thanks to the superb sensitivity and angular resolution provided by the new radio, infrared, and optical facilities. Here, we report one more explosive outflow related with the massive and bright star-forming region IRAS 12326-6245 using Band 6 sensitive and high-angular-resolution (~0.″2) Atacama Large Millimeter/Submillimeter Array observations. We find over 10 molecular and collimated well-defined streamers, with Hubble-Lemaitre-like expansion motions, and pointing right to the center of a dusty and molecular shell (reported for the first time here) localized in the northern part of the UC H II region known as G301.1A. The estimated kinematic age and energy for the explosion are ~700 yr and 10⁴⁸ erg, respectively. Taking into account the recently reported explosive outflows together with IRAS 12326-6245, we estimate an event rate of once every 90 yr in our Galaxy, similar to the formation rate of massive stars.