A team of researchers from the University College London has uncovered how galaxies change their shape. They found that galaxies undergo a process called "morphological quenching", which is caused by the removal of gas from their interstellar medium. This gas removal can be the result of several different processes, including:

* Star formation: When stars form, they consume gas from the interstellar medium.

* Gas inflows: Gas inflows from the surrounding intergalactic medium can be stopped by various processes, such as ram pressure stripping and galaxy interactions.

* Outflows: Gas outflows driven by feedback from active galactic nuclei or stellar winds can expel gas from the galaxy.

Morphological quenching can cause galaxies to change from spiral galaxies to elliptical galaxies. Spiral galaxies have a disk-like structure with spiral arms, while elliptical galaxies have a smooth, elliptical shape.