We use numerical simulations of isolated galaxies to study the effects of stellar feedback on the formation and evolution of giant star-forming gas ‘ ‘ clumps ’ ’ in high-redshift , gas-rich galaxies .
Such galactic disks are unstable to the formation of bound gas-rich clumps whose properties initially depend only on global disk properties , not the microphysics of feedback .
In simulations without stellar feedback , clumps turn an order-unity fraction of their mass into stars and sink to the center , forming a large bulge and kicking most of the stars out into a much more extended stellar envelope .
By contrast , strong radiative stellar feedback disrupts even the most massive clumps after they turn \sim 10 - 20 \% of their mass into stars , in a timescale of \sim 10 - 100 Myr , ejecting some material into a super-wind and recycling the rest of the gas into the diffuse ISM .
This suppresses the bulge formation rate by direct ‘ ‘ clump coalescence ’ ’ by a factor of several .
However , the galactic disks do undergo significant internal evolution in the absence of mergers : clumps form and disrupt continuously and torque gas to the galactic center .
The resulting evolution is qualitatively similar to bar/spiral evolution in simulations with a more homogeneous ISM .