We present observational results of the [ Fe ii ] \lambda 1.644 \mu m emission from the jets of L1551 IRS 5 .
The data sets were obtained through 13 fully sampled slits aimed at the base of the jets .
These sets are used to construct a three-dimensional cube .
The field of view was 5 . ^ { \prime \prime } 8 \times 4 . ^ { \prime \prime } 2 .
We confirmed that the position of the knot PHK1 coincides with a stationary , point-like x-ray source within \pm 0 \farcs 3 .
The northern and southern jets are distinguished from each other at a point 0 \farcs 6 away from their driving sources .
We also confirmed that the northern jet consists of well-separated high- and low-velocity components ( HVC and LVC , respectively ) .
The HVC has a terminal velocity of \sim 400 km s ^ { -1 } and shows a consistently narrow velocity width of 40 km s ^ { -1 } .
The LVC covers the velocity range from V _ { LSR } = 0 to - 240 km s ^ { -1 } and has broad velocity widths of \sim 150–180 km s ^ { -1 } .
These decrease with distance from the driving sources .
The spatial width of the LVC varies from 0 \farcs 6–0 \farcs 7 at V _ { LSR } \sim - 200 km s ^ { -1 } to 0 \farcs 8–0 \farcs 9 at V _ { LSR } \sim - 30 km s ^ { -1 } .
These characteristics are well understood in terms of the two types of outflow mechanisms that are working simultaneously : one is the HVC , which is launched in a narrow , inner radial region at 0.04–0.05 AU , and the other is the LVC , which is launched in a wider , outer radial region from within 0.1–4.5 AU of the accretion disk .
Part of the LVC emission could arise in the gas entrained or shocked by the HVC .
We also discuss the possibility that part of the HVC gas is thermalized at PHK1 to produce the x-ray emission and LVC .