Star Formation and Feedback: A Molecular Outflow-Prestellar Core
  Interaction in L1689N
  We present Herschel, ALMA Compact Array (ACA), and Caltech Submillimeter
Observatory (CSO) observations of the prestellar core in L1689N, which has been
suggested to be interacting with a molecular outflow driven by the nearby solar
type protostar IRAS 16293-2422. This source is characterized by some of the
highest deuteration levels seen in the interstellar medium. The change in the
NH2D line velocity and width across the core provides clear evidence of an
interaction with the outflow, traced by the high-velocity water emission.
Quiescent, cold gas, characterized by narrow line widths is seen in the NE part
of the core, while broader, more disturbed line profiles are seen in the W/SW
part. Strong N2D+ and ND3 emission is detected with the ACA, extending S/SW
from the peak of the single-dish NH2D emission. The ACA data also reveal the
presence a compact dust continuum source, with a mean size of ~1100 au, a
central density of (1-2) 10^7 cm-3, and a mass of 0.2-0.4 Msun. The dust
emission peak is displaced ~5" to the south with respect to the N2D+ and ND3
emission, as well as the single-dish dust continuum peak, suggesting that the
northern, quiescent part of the core is characterized by spatially extended
continuum emission, which is resolved out by the interferometer. We see no
clear evidence of fragmentation in this quiescent part of the core, which could
lead to a second generation of star formation, although a weak dust continuum
source is detected in this region in the ACA data.
