We present new 37.7 \mu m far-infrared imaging of the infrared luminous ( L _ { IR } \sim 5.16 \times 10 ^ { 11 } L _ { \sun } ) interacting galaxy Arp 299 ( = IC 694 + NGC 3690 ) .
We show that the 38 \mu m flux , like the 60 and 100 \mu m emission , traces the luminosity of star forming galaxies , but at considerably higher spatial resolution .
Our data establish that the major star formation activity of the galaxy originates from a point source in its eastern component , IC 694 , which is inconspicuous in the optical , becoming visible only at the near and mid-infrared .
We find that IC 694 is two times more luminous than NGC 3690 , contributing to more than 46 % of the total energy output of the system at this wavelength .
The spectral energy distribution of the different components of the system clearly shows that IC 694 , has 6 times the infrared luminosity of M82 and it is the primary source responsible for the bolometric luminosity of Arp 299 .