Collision of molecular outflows in the L1448–C system

Abstract

ABSTRACT We present a study of the central zone of the star-forming region L1448 at 217–230 GHz (∼1.3 mm) using Atacama Large Millimeter Array observations. Our study focuses on the detection of proto-stellar molecular outflows and the interaction with the surrounding medium towards sources L1448–C(N) and L1448–C(S). Both sources exhibit continuum emission, with L1448–C(N) being the brightest one. Based on its spectral index and the associated bipolar outflow, the continuum emission is the most likely to be associated with a circumstellar disk. The 12CO(J = 2→1) and SiO(J = 5→4) emissions associated with L1448–C(N) trace a bipolar outflow and a jet oriented along the northwest-southeast direction. The 12CO(J = 2→1) outflow for L1448–C(N) has a wide-open angle and a V-shape morphology. The SiO jet is highly collimated and has an axial extent comparable with the 12CO(J = 2→1) emission. There is not SiO(J = 5→4) emission towards L1448–C(S), but there is 12CO(J = 2→1) emission. The observations revealed that the red-shifted lobes of the 12CO(J = 2→1) outflows of L1448–C(N) and L1448–C(S) are colliding. As a result of this interaction, the L1448-C(S) lobe seems to be truncated. The collision of the molecular outflows is also hinted by the SiO(J = 5→4) emission, where the velocity dispersion increases significantly in the interaction zone. We also investigated whether it could be possible that this collision triggers the formation of new stars in the L1448–C system.