Star-forming disk galaxies at high redshift are often subject to violent disk instability , characterized by giant clumps whose fate is yet to be understood .
The main question is whether the clumps disrupt within their dynamical timescale ( \leq 50 Myr ) , like the molecular clouds in today ’ s galaxies , or whether they survive stellar feedback for more than a disk orbital time ( \approx 300 Myr ) in which case they can migrate inward and help building the central bulge .
We present 3.5-7 pc resolution AMR simulations of high-redshift disks including photo-ionization , radiation pressure , and supernovae feedback .
Our modeling of radiation pressure determines the mass loading and initial velocity of winds from basic physical principles .
We find that the giant clumps produce steady outflow rates comparable to and sometimes somewhat larger than their star formation rate , with velocities largely sufficient to escape galaxy .
The clumps also lose mass , especially old stars , by tidal stripping , and the stellar populations contained in the clumps hence remain relatively young ( \leq 200 Myr ) , as observed .
The clumps survive gaseous outflows and stellar loss , because they are wandering in gas-rich turbulent disks from which they can re-accrete gas at high rates compensating for outflows and tidal stripping , overall keeping realistic and self-regulated gaseous and stellar masses .
Our simulations produce gaseous outflows with velocities , densities and mass loading consistent with observations , and at the same time suggest that the giant clumps survive for hundreds of Myr and complete their migration to the center of high-redshift galaxies , without rapid dispersion and reformation of clumps .
These long-lived clumps can be involved in inside-out evolution and thickening of the disk , spheroid growth and fueling of the central black hole .