Observations of Shocked H[TINF]2[/TINF] and Entrained CO in Outflows from Luminous Young Stars

Abstract

Narrowband, (10) S(1) images of six luminous outow regions are presented and discussed. In ve H 2 of these regions, W75 N, S140 N, NGC 7538, AFGL 5180, and AFGL 490, shock features associated H 2 with molecular (CO) outows are observed. We have discovered faint, though extensive, bow shocks in the W75 N outow that indicate a total ow length of at least 3 pc. The Herbig-Haro knots that make up the HH 251254 outow in S140 N are also observed in in addition, knots in the counterow H 2 ; are discovered. Copious emission is also observed throughout the NGC 7538 region ; lamentary H 2 structures to the northeast of the central cluster (IRS 1) are probably photodissociation fronts, although a jetlike structure is observed associated with the IRS 9 CO outow. In AFGL 5180, a new, collimated jet is discovered to the east of the central cluster, and numerous knots and laments are observed H 2 around the cluster itself that could be associated with the known CO outow there. Last, line emis-H 2 sion is observed southwest of AFGL 490 ; in particular, a bright peak is found associated with a warm molecular clump in the CO outow.