Geometric and Kinematic Structure of the Outflow/Envelope System of
  L1527 Revealed by Subarcsecond-resolution Observation of CS
  Subarcsecond-resolution images of the rotational line emissions of CS and
c-C$_3$H$_2$ obtained toward the low-mass protostar IRAS 04368$+$2557 in L1527
with the Atacama Large Millimeter/submillimeter Array are investigated to
constrain the orientation of the outflow/envelope system. The distribution of
CS consists of an envelope component extending from north to south and a faint
butterfly-shaped outflow component. The kinematic structure of the envelope is
well reproduced by a simple ballistic model of an infalling rotating envelope.
Although the envelope has a nearly edge-on configuration, the inclination angle
of the rotation axis from the plane of the sky is found to be 5$^\circ$, where
we find that the western side of the envelope faces the observer. This
configuration is opposite to the direction of the large-scale ($\sim$ 10$^4$
AU) outflow suggested previously from the $^{12}$CO ($J$=3$-$2) observation,
and to the morphology of infrared reflection near the protostar ($\sim$ 200
AU). The latter discrepancy could originate from high extinction by the outflow
cavity of the western side, these discrepancies or may indicate that the
outflow axis is not parallel to the rotation axis of the envelope.
Position-velocity diagrams show the accelerated outflow cavity wall, and its
kinematic structure in the 2000 AU scale is explained by a standard parabolic
model with the inclination angle derived from the analysis of the envelope. The
different orientation of the outflow between the small and large scale implies
a possibility of precession of the outflow axis. The shape and the velocity of
the outflow in the vicinity of the protostar are compared with those of other
protostars.
