A Variable-Velocity, Precessing Jet Model for HH 32

Abstract

HH 32 has a bright, strongly redshifted lobe with a system of scattered condensations. We propose that these condensations correspond to internal working surfaces in a variable ejection velocity, precessing jet. From a three-dimensional numerical simulation, we obtain predictions of [O II] lambda3726+ lambda3729, [ O III] lambda5007, [ O I] lambda6300, Halpha, [N II] lambda6583, and [S II] lambda6716+ lambda6731 intensity maps, for an orientation angle of similar to70degrees between the outflow axis and the plane of the sky ( as appropriate for HH 32). We also obtain predictions of radial velocity channel maps. We then compare these predictions with previously published observations of HH 32 and discuss the strengths and weaknesses of the model.