2025AJ....169..324I

This paper reports on the detection of a likely explosive outflow in the high-mass star-forming complex G34.26+0.15, adding to the small number (six) of explosive outflows detected so far. ALMA CO(2-1) and SiO(5-4) archival observations reveal multiple outflow streamers from G34.26+0.15, which correlate well with H₂ jets identified from Spitzer-IRAC 4.5 μm and [4.5]/[3.6] flux ratio maps. These nearly linear outflow streamers originate from a common center within an ultracompact H II region located in the complex. The velocity spread of the outflow streamers ranges from 0 to 120 km s^–1. The radial velocities of these streamers follow the Hubble-Lemaître velocity law, indicating an explosive nature. From the CO emission, the total outflow mass, momentum, and outflow energy are estimated to be ∼264 M_⊙, 4.3 × 10³M_⊙ km s^–1, and 10⁴⁸ erg, respectively. The event triggering the outflow may have occurred about 19,000 yr ago and could also be responsible for powering the expanding UC H II region, given the similar dynamical ages and positional coincidence of the UC H II region with the origin of the outflow. The magnetic field lines in the region associated with G34.26+0.15 also appear to align with the direction of the outflow streamers and jets, possibly being dragged by the explosive outflow.