Confirming the Explosive Outflow in G5.89 with ALMA

Luis A. Zapata … [et al.].

Serie: Trabajos publicados del IAR ; no. 1580

Resumen: 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 UCHII region G5.89−0.39 that indicates that this phenomenon is not unique to Orion or DR21. Sensitive and high angular resolution (∼ 0.100) 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 UCHII 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.