Source always of quite unusual and strongly augmented radiation? (6)
I believe the answer is:
quasar
'source' is the definition.
(I have seen 'source of radiation' mean 'quasar' so perhaps 'source' could also mean 'quasar')
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for quasar that I've seen before include "Remote radiation source" , "Remote celestial body emitting huge amounts of energy" , "Source of radiation in space" , "Distant, mystery sky object" , "Massive, extremely distant celestial object" .)