VLA ammonia observations of L1287: analysis of the "Guitar" core and two
  filaments
  The present work aims at studying the dense gas of the molecular cloud LDN
1287 (L1287), which harbors a double FU Ori system, an energetic molecular
outflow and a still-forming cluster of deeply embedded low-mass, young stellar
objects, showing a high level of fragmentation. We present optical Halpha and
[SII], and VLA NH$_3$ (1,1) and (2,2) observations with an angular resolution
of ~3.5''. The observed NH$_3$ spectra have been analyzed with the HfS tool,
fitting simultaneously three different velocity components. The NH$_3$ emission
from L1287 comes from four different structures: a core associated with RNO 1,
a guitar-shaped core (the "Guitar") and two interlaced filaments (the Blue and
Red Filaments) roughly centered towards the binary FU Ori system RNO 1B/C and
its associated cluster. Regarding the Guitar Core, there are clear signatures
of gas infall onto a central mass that has been estimated to be ~2.1 $M_\odot$.
Regarding the two filaments, they have radii ~0.03 pc, masses per unit length
~50 $M_\odot$ pc$^{-1}$, and are near isothermal equilibrium. A central cavity,
probably related with the outflow, and also traced by the Halpha and [SII]
emission, is identified, with several young stellar objects near its inner
walls. Both filaments show clear signs of perturbation by the high-velocity gas
of the outflows driven by one or several young stellar objects of the cluster.
The Blue and Red filaments are coherent in velocity and have nearly subsonic
gas motions, except at the position of the embedded sources. Velocity gradients
across the Blue Filament can be interpreted either as infalling material onto
the filament or rotation. Velocity gradients along the filaments are
interpreted as infall motions towards a gravitational well at the intersection
of both filaments.
