We present near-infrared J ( 1.25 \mu m ) , H ( 1.65 \mu m ) , and K _ { s } ( 2.17 \mu m ) imaging of the entire supernova remnant IC 443 from the Two Micron All Sky Survey ( 2MASS ) , and Infrared Space Observatory ( ISO ) LWS observations of [ O I ] for 11 positions in the northeast .
Near-infrared emission from IC 443 was detected in all three bands from most of the optically bright parts of the remnant , revealing a shell-like morphology , with bright K _ { s } band emission along the southern ridge and bright J and H along the northeastern rim .
The total luminosity within the 2MASS bands is 1.3 \times 10 ^ { 36 } erg s ^ { -1 } .
These data represent the first near-infrared images that are complete in coverage of the remnant .

The color and morphological structure are very different between the northeastern and southern parts .
J and H band emission from the northeast rim is comparably bright and can be explained mostly by [ Fe II ] line emission .
The hydrogen recombination lines , P \beta and Br10 , should also be present in the broad-band images , but probably contribute less than 10 % of the J and H band fluxes .
Strong [ O I ] ( 63 \mu m ) lines were detected crossing the northeastern rim , with the strongest line in the northeastern shell where the near-infrared emission shows filamentary structure .
In contrast , the southern ridge is dominated by K _ { s } band light exhibiting a clumped and knotty structure .
A two excitation temperature model derived from previous ISO and ground-based observations predicts that H _ { 2 } lines can explain most of K _ { s } band and at least half of J and H band emission .
Hence , the prominent broad-band color differences arise from physically different mechanisms : atomic fine structure lines along the northeastern rim and molecular ro-vibrational lines along the southern ridge .
Shock models imply a fast J-shock with v _ { s } \sim 100 km s ^ { -1 } and 10 < n _ { o } < 10 ^ { 3 } cm ^ { -3 } for the northeastern rim and a slow C-shock with v _ { s } \sim 30 km s ^ { -1 } and n _ { o } \sim 10 ^ { 4 } cm ^ { -3 } for the southern ridge , respectively .

The shocked H _ { 2 } line emission is well known from the southern sinuous ridge , produced by an interaction with dense molecular clouds .
The large field of view and color of the 2MASS images show that the K _ { s } band emission extends to the east and the northeast , suggesting that the interaction extends to the inner part of the northeastern shell .
Our new CO map of the inner part of the northeast quadrant shows good correspondence with the K _ { s } -band map .
The CO lines are broad , confirming that the K _ { s } -band emission is due to shocked H _ { 2 } .

Subject headings : infrared : shock waves - nebula : individual ( IC 443 ) - ISM : supernova remnants