丁香园AV

Synopsis

It is well established that galaxies are divided into those that are star-forming and those that have stopped forming stars long ago.  The cessation of star formation in galaxies ("quenching") correlates strongly with both galaxy morphology and environment, but the physical reasons behind these relationships remain disputed.  Reviewing developments in galaxy evolution research, I will discuss issues of correlation and causation, and highlight evidence that points to multiple evolutionary pathways along which galaxies both grow and die.