A hot molecular outflow driven by the ionized jet associated with IRAS 16562-3959

Abstract

We report molecular line observations in the CO J = 3 → 2, 6 → 5, and 7 → 6 transitions, made using the Atacama Pathfinder Experiment Telescope, toward the massive and dense core IRAS 16562-3959. This core harbors a string of radio sources thought to be powered by a central collimated jet of ionized gas. The molecular observations show the presence of high-velocity gas exhibiting a quadrupolar morphology, most likely produced by the presence of two collimated outflows. The southeast-northwest (SE-NW) molecular outflow is aligned with the string of radio continuum sources, suggesting it is driven by the jet. We find that the excitation temperature of the gas in the SE-NW outflow is high, with values of 145 and 120K for the blueshifted and redshifted lobes, respectively. This outflow has a total mass of 1.92 M⊙, a total momentum of ∼89 M⊙kms-1, and an averaged momentum rate of ∼3.0 × 10-2 M⊙kms -1yr-1, values characteristic of flows driven by young massive stellar objects with high luminosities (Lbol ∼ 2 × 104 L⊙). Complementary data taken with the Atacama Submillimeter Telescope Experiment in high density and shock tracers support the picture that IRAS 16562-3959 is an accreting young massive star associated with an ionized jet, which is the energy source of a molecular outflow. © 2011. The American Astronomical Society. All rights reserved.