The straight and isolated G350.54+0.69 filament: density profile and
  star formation content
  We investigate the global properties of the straight and isolated filamentary
cloud G350.54+0.69 using Herschel continuum and APEX molecular line data. The
overall straight morphology is similar to two other well studied nearby
filaments (Musca and Taurus-B211/3) while the isolated nature of G350.54+0.69
appears similar to Musca. G350.54+0.69 is composed of two distinct filaments
with a length ~5.9 pc for G350.5-N (~2.3 pc for G350.5-S), a total mass of ~810
$M_{\odot}$ (~ 110 $M_{\odot}$), and a mean temperature of ~ 18.2 K (~17.7 K).
We identify 9 dense and gravitationally bound cores in the whole cloud
G350.54+0.69. The separations between cores and the line mass of the whole
cloud appear to follow the predictions of the "sausage" instability theory,
which suggests that G350.54+0.69 could have undergone radial collapse and
fragmentation. The presence of young protostars is consistent with this
hypothesis. The line masses of the two filaments (~120 $M_{\odot}$ pc$^{-1}$
for G350.5-N, and ~45 $M_{\odot}$ pc$^{-1}$ for G350.5-S), mass-size
distributions of the dense cores, and low-mass protostars collectively suggest
that G350.54+0.69 is a site of ongoing low-mass star formation. Based on the
above evidence, we place G350.54+0.69 in an intermediate evolutionary state
between Musca and Taurus-B211/3. We suggest that investigations into straight
(and isolated) versus those distributed inside molecular clouds may provide
important clues into filament formation and evolution.
