Fig.
Schematic of a disk, an extended disk, infall, and outflow in the protostar
L1157. (a) In the plane of the sky, the
LOS toward the observer is outward perpendicular to the
paper. In L1157, the disk is seen nearly edge-on, with an
inclination of 5°. (b) Along the line of sight,
for the redshifted infall,
the cooler layers are in the foreground while for the blueshifted infall,
the cooler layers are in the background. (c)
Schematic methanol emission profiles along the major axis
of the projected disk in the sky plane as shown above,
in (a), for the blue- and redshifted
infall layers.