2020/10/26 by Luis A. Zapata, Paul T. P. Ho, Manuel Fernández-López +9 · 2 citations
Physics and Astronomy · #astro-ph.GA #astro-ph.SR
paper · pdf · doi:10.3847/2041-8213/abbd3f
Accepted by ApJ Letters. The animation is located here: https://drive.google.com/file/d/1a1c9JMwm0Mf8CxlfuEzyh6XmCOsgOyMA/view?usp=sharing
arxiv created 2020/10/26 · arxiv updated 2020/11/04
The explosive molecular outflow detected decades ago in the Orion BN/KL region of massive star formation was considered to be a bizarre event. This belief was strengthened by the non detection of similar cases over the years with the only exception of the marginal case of DR21. Here, we confim a similar explosive outflow associated with the UCH\rm II region G5.89-0.39 that indicates that this phenomenon is not unique to Orion or DR21. Sensitive and high angular resolution (∼ 0.1'') ALMA CO(2-1) and SiO(5-4) observations show that the molecular outflow in the massive star forming region G5.89-0.39 is indeed an explosive outflow with an age of about 1000 yrs and a liberated kinetic energy of 1046-49 erg. Our new CO(2-1) ALMA observations revealed over 30 molecular filaments, with Hubble-like expansion motions, pointing to the center of UCH\rm II region. In addition, the SiO(5-4) observations reveal warmer and strong shocks very close to the origin of the explosion, confirming the true nature of the flow. A simple estimation for the occurrence of these explosive events during the formation of the massive stars indicates an event rate of once every ∼100 yrs, which is close to the supernovae rate.