These supernovae are counter-intuitive in the sense that normally people think of anti-matter as "bring it into contact with normal matter and it will explode".

These supernovae are counter-intuitive in the sense that normally people think of anti-matter as "bring it into contact with normal matter and it will explode". Here, it's the production of anti-matter that robs pressure and triggers the collapse. But the thing that always baffles me is how something that is collapsing inward like that can explode without leaving a remnant. You have to somehow get all the mass out of the potential well, and it's not easy to take 10 solar masses of material falling inward at an appreciable fraction of the speed of light and turn it around and shoot it out...