Butter made out of pasteurized cream?

No, cream and butter are not the same thing. Butter is made by agitating cream, causing the fat to clump up and separate from the rest of the cream. The butter is then washed, optionally salted, and pressed. So the “ingredients” of butter are cream and optionally salt.

Pasteurization is a process for inactivating microorganisms in foods like milk and cream by heating them to a fairly high temperature for a short period of time. It has the effect of increasing shelf life and reducing the risk of food-borne illness. All dairy products you buy at the grocery store, with the possible exception of some fancy cheeses, have been pasteurized.