Is the gamma-ray burst a spherical field, or is it a narrow, directed cone? If the latter, I wonder how the burst spreads/diffuses as it travels and what sort of equation governs the energy flux with respect to distance and initial conditions.
Then you can figure out the flux from the area of a circle on a sphere, which is something like 2πr^2(1−cosθ) Where theta is the opening angle and r is the distance from point of emanation of the GRB.
e.g. in a spiral galaxy, do they tend to align with the axis of rotation and so do less damage locally (spray out "up and down" from the galaxy)?
https://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and...