In “Ultraviolet light” and “X-ray” light wavelength regions are needed to carry out observations to study the “accretion disk” around “a white dwarf” in a “binary system”.
Step-by-step explanation:
Occurrence of an accretion disk is due to presence of diffuse material around a white dwarf in orbital motion. White dwarf is constituted from electron-degenerate matter therefore also called as degenerate dwarf in binary system. Frictional forces and gravitational forces are responsible to compress and high “temperature” of the material, results with emission of “electromagnetic radiation”. “Accretion disks” of white dwarf radiate in the UV-rays and X-rays wavelength region of spectrum.