An Analysis of the Complex and Compact Outflow Cavity Carved by HOPS 361-A in NGC 2071 IR

Abstract

We present a combined Stratospheric Observatory for Infrared Astronomy (SOFIA) and two-epoch Hubble Space Telescope (HST) study of the region NGC 2071 IR containing the outflow from the protostar HOPS 361-A (NGC 2071 IRS 1). New [O i] 63 μm spectra, taken with the German REciever for Astronomy at Terahertz frequencies (GREAT) instrument aboard SOFIA, trace the outflow, spectrally resolve line profiles, and give radial velocities of the far-IR emission to yield 3D kinematics, shock properties, and feedback properties. Proper motions and extinction values from HST give a more complete quasi-3D picture that we use to model shock speeds and densities. We identify 14 distinct features that show proper motions. Combined with the GREAT data, we estimate that HOPS 361-A has a mass outflow rate of 3.16 × 10−6 M ⊙ yr−1 with shock speeds up to 51 km s−1. The outflow force summed over all knots per area is measured to be 1.45 × 10−4 M ⊙ km−1 s−1 yr−1 and a power summed over all knotsper area of 2.37 × 10−2 M ⊙ s−3 dissipated assuming constant M ̇ , with large uncertainties on the feedback values. The total [O i] luminosity using all SOFIA apertures encompassing the HOPS 361 clump is 0.7 L ⊙, corresponding to a mass outflow rate of 7 × 10−5 M ⊙ yr−1. This is the second 3D kinematic study of an outflow in NGC 2071 IR in the near- and far-IR regimes following Rubinstein et al. (2023). The SOFIA [O i] spectra add unique focus to the entrained gas connecting the recent episode of outflows from HOPS 361-A to the outflow cavity and the surrounding NGC 2071 IR star-forming environment.