απαυγασμα is radiance:
The Son is the radiance of God’s glory and the exact representation of his being, sustaining all things by his powerful word. After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven. (Hebrews 1:3, NIV)
I see three possible ways radiance can be understood by the context:
The Son is like beams of light fully representing the Father. This would imply radiance in an active sense of radiating, as lightwaves move across the universe.
The Son is like light reflecting in a mirror by which we see the Father. Again this would imply active wavelengths of light hitting our retina in order for us to see the original source of the reflection.
The Son is a person embodying the full light of the Father. This would be like a Sun, giving birth to another Sun, so that the representation of the born Sun is just like the original Sun.
What I am wondering is, does the sense of the word απαυγασμα from a pure languages analysis lend itself more towards one of these three understandings, or must a decision be made between them be purely based from a theological and contextual ground?