Thermal <interstellar dust> produces a bright <galactic foreground> concentrated toward the <Milky Way> plane, with additional cloud structure. Its emission spectrum differs from the approximately $2.73\,\mathrm K$ <blackbody> spectrum of the <cosmic microwave background>, so comparisons across <frequencies> help separate it. In the sketch below this is the bright equatorial band.

Solution

Past exam of the short options paper shared by Prelims and Parts A and B of the physics course of the University of Oxford / 2012 / S2 / 3 / a / Solution

 Solution (source code)