It's the inverted version of the joy division unknown pleasure album cover that was originally a textbook page describing neutron star patterns

(White with black lines, I have the inverse on my other phone. I'll have to switch the backgrounds .⁠·⁠´⁠¯⁠`⁠(⁠>⁠▂⁠<⁠)⁠´⁠¯⁠`⁠·⁠.)