10 X-Ray

図 10: X-Ray

Composite X-ray intensity observed by the Position-Sensitive Proportional Counter (PSPC) instrument on the R?ntgen Satellite (ROSAT). Images in three broad, soft X-ray bands centered at 0.25 , 0.75, and 1.5 keV are encoded in the red, green, and blue color ranges, respectively. In the Milky Way, extended soft X-ray emission is detected from hot, shocked gas. At the lower energies especially, the interstellar medium strongly absorbs X-rays, and cold clouds of interstellar gas are seen as shadows against background X-ray emission. Color variations indicate variations of absorption or of the temperatures of the emitting regions. The black regions indicate gaps in the ROSAT survey.

$$60 \sim 360 \times 10^{6} {\rm GHz} = 8.32757 \times 10^{-10} \sim 4.99654 \times 10^{-9} {\rm m} = 8.32757 \sim 49.9654 {\rm\AA}$$