What concept refers to a galactic structure where star birth processes have halted, leaving mostly older stars?

Answer

Dead disk

A 'dead disk' specifically refers to a galactic structure where the sustained processes required for star birth have stopped, resulting in a system dominated by older stars.

What concept refers to a galactic structure where star birth processes have halted, leaving mostly older stars?
Spacegalaxiesastronomycosmologydead galaxies