6 Mid-infrared (6.8 -10.8 microns)

図 7: Mid Infrared

Mid-infrared emission observed by the SPIRIT III instrument on the Midcourse Space Experiment (MSX) satellite. Most of the diffuse emission in this wavelength band is believed to come from complex molecules called polycyclic aromatic hydrocarbons, which are commonly found both in coal and interstellar gas clouds. Red giant stars, planetary nebulae, and massive stars so young that they remain deeply embedded in their parental molecular gas clouds produce the multitude of small bright spots seen here. Unlike most of the other maps, this map extends only to 5° above and below the Galactic plane.

$$3.0\times 10^{3} \sim 25\times 10^{3} {\rm GHz} =0.0000119917 \sim 0.0000999308 {\rm m} =12 \sim 100 {\rm\mu m}$$