How to pronounce “compaction” in English

We can follow in the individual simulations-- this is the inner part of the galaxy, the very center part of the galaxy, and we noticethat the center part of the galaxy is mostly dark matter until what we call a "compaction event" occurs.A lot of gas flows into the center-- there's the gas flowing into the center-- and it becomes stars.

Gas and stars, edge-on.Here it goes. So you see that there's a compaction event about to occur.A bunch of gas just flowed into the center, and the center is now becoming much rounder.