Past exam of the mathematics course of the University of Cambridge 2009 iii Paper 65 4 viii Solution Created 2026-10-03 Updated 2026-10-14
In a compact starburst galaxy, stellar feedback can approach the radiation-pressure limit of a dusty starburst, , so stronger luminosity drives a galactic outflow rather than allowing indefinitely increasing star formation rate. Optically thick starburst-disk calculations give a characteristic infrared flux near ; with and an emitting area of order , this corresponds to and would consume of gas in only . Feedback and a finite fuel supply produce a characteristic upper scale for compact bursts, rather than a universal ceiling on the total rate independent of star-forming area and gas supply.