Diffuse X-ray background
= Diffuse X-ray background
<Diffuse X-ray background> is <X-ray> emission spread over the instrument's observed sky rather than assigned to a single resolved source. Diffuse appearance at finite <angular resolution> does not prove emission by a continuous medium: many unresolved <point-like astronomical sources> can also give a smooth signal. Instrumental background is a separate contribution, even though both enter measured counts.