The outflow activity of the protostars in S140 IRS

Thomas Preibisch & Michael D. Smith

Astronomy & Astrophysics, 383, 540 (2002)


The S140/L1204 cloud contains a deeply embedded region of star formation and a powerful molecular outflow. In this paper, we present images of the S140 region obtained in the light of the 2.12 micro-meter molecular hydrogen emission line and adjacent continuum. Our images reveal several knots of H_2 line emission originating from shocked material close to IRS 1 as well as further out. Strong H_2 shock emission is found north-east of IRS1 (at position angle of ~ 20degr - 30degr), as well as to the south-west of IRS1 (at position angles around ~ 190degr - 220degr), clearly demonstrating the presence of outflow activity in the north-east/south-west direction. We also find patches of H_2 emission several arcminutes away from IRS1 at a position angles of ~150degr and ~340degr, i.e. in directions consistent with the previously known north-west/south-east molecular outflow. Our results therefore provide evidence for the existence of two distinct bipolar outflow systems originating simultaneously from IRS 1. We also discuss general aspects of the star formation process in the S140 region. An inferred high ratio of stellar to gas mass suggests that the outflows have dispersed most of the cloud mass.

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