What is the blast radius of the Archon's Blazing Pinions attack?

After some testing, I've confirmed that the blast radius of each pillar is exactly 2 tiles (not counting the center tile).

Visually, the blast radius looks like this:

enter image description here

The red and black tiles indicate where your units will definitely take damage. I'm not sure if any of the gray tiles on the diagonals are also in the blast radius though.