Elisabetta Cavazzuti

Throw pebbles along a tight row of posts: they ricochet into a dense spray. Throw at an angle, and they scatter. Gamma rays in a crystal do the same: they spawn particle cascades that spread out unless the crystal’s atomic rows are perfectly aligned. Align them within a hair’s width, and the cascade sharpens into a tight beam. A small crystal then outperforms a large one.

The edge of the supernova remnant RCW 86 is where the shock wave from a star's explosion slams into the surrounding gas. The IXPE telescope looked at the southwestern part of this boundary in X-rays and tried to catch polarization — the way these rays oscillate.