The evolution of star-forming galaxies at high redshifts is very sensitive to
the strength and nature of stellar feedback. Using two sets of cosmological,
zoom-in simulations from the VELA suite, we compare the effects of two
different models of feedback: with and without kinetic feedback. At a fixed
halo mass and redshift, the stellar mass is reduced by a factor of 1-3 in the
models with stronger feedback, so the stellar-mass-halo-mass relation is in
better agreement with abundance matching results. On the other hand, galaxy
elongation is robust against feedback strength. At a fixed stellar mass, Ms <
10^10 Msun, galaxies are more elongated in the strong-feedback case. More
massive, star-forming discs with high surface densities form giant clumps.
However, the population of round, compact, old (age_c > 300 Myr), quenched,
stellar (or gas-poor) clumps is absent in the model with strong feedback. On
the other hand, giant star-forming clumps with intermediate ages (age_c =
100-300 Myr) can survive for several disc dynamical times, independently of
feedback strength. The evolution through compaction followed by quenching in
the plane of central surface density and specific star-formation rate is
similar under the two feedback models.Comment: 14 pages, 12 figures, submitted to MNRA