Formation of new stellar populations from gas accreted by massive young star clusters

Understand

Stars in star clusters are thought to form in a single burst from a common progenitor cloud of molecular gas.

• However, massive, old globular clusters -- with ages greater than 10 billion years and masses of several hundred thousand solar masses -- often harbour multiple stellar populations, indicating that more than one star-forming event occurred during their lifetimes.
• Colliding stellar winds from late-stage, asymptotic-giant-branch stars are often invoked as second-generation star-formation trigger.
• The initial cluster masses should be at least 10 times more massive than they are today for this to work.