The outflow activity of the protostars in S140 IRS^*

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
² Armagh Observatory, College Hill, Armagh BT61 9DG, Northern Ireland

Corresponding author: T. Preibisch, preib@mpifr-bonn.mpg.de

Received: 24 October 2001
Accepted: 30 November 2001

Abstract

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 μm molecular hydrogen emission line and adjacent continuum. Our images reveal several knots of H₂ line emission originating from shocked material close to IRS 1 as well as further out. Strong H₂ shock emission is found north-east of IRS1 (at position angle of ~20°–30°), as well as to the south-west of IRS1 (at position angles around ~190°–220°), clearly demonstrating the presence of outflow activity in the north-east/south-west direction. We also find patches of H₂ emission several arcminutes away from IRS1 at a position angles of ∼150° and , 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.