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arXiv · 2210.15372

Effects of feedback on galaxies in the VELA simulations: elongation, clumps and compaction

Daniel Ceverino·Nir Mandelker·Gregory F. Snyder·Sharon Lapiner·Avishai Dekel·Joel Primack·Omri Ginzburg·Sean Larkin
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Abstract

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 from the expansion of supernovae shells and stellar winds. 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, the three-dimensional shape of low-mass galaxies is elongated along a major axis in both models. 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.

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Daniel Ceverino, Nir Mandelker, Gregory F. Snyder, Sharon Lapiner, Avishai Dekel, Joel Primack, Omri Ginzburg, Sean Larkin. 2022-10-27. Effects of feedback on galaxies in the VELA simulations: elongation, clumps and compaction. https://doi.org/10.1093/mnras/stad1255

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