Large-scale turbulent driving regulates star formation in high-redshift gas-rich galaxies II: Influence of magnetic field and turbulent compressive fraction

The observed star formation rate in galaxies is well below what it should be if only gravitational collapse was at play. There is still no consensus on what is the main process responsible for the regulation the star formation rate. It has recently been shown that one candidate to regulate star formation, the feedback from massive stars, is suitable only if the mean column density at the kiloparsec scale is not too high, under $\approx 20 \mathrm{M}_\odot\cdot\mathrm{pc}^{-2}$. On the other-hand, intense large scale turbulent driving could possibly slow down star formation in high density environment to values compatible with observations. In this work we explore the effect of the nature and strength of the turbulent driving, as well as the effect of the magnetic field. We perform a large series of feedback regulated numerical simulations of the interstellar medium (ISM) in which bidimensional large scale turbulent driving is also applied. We determine the driving intensity needed to reproduce the Schmidt-Kennicutt (SK) relation for several gas column densities, magnetization and driving compressibility. We confirm that in the absence of turbulent forcing, and even with substantial magnetic field, the SFR is too high, particularly at high column density, compared to the SK relation. We find that the SFR outcome depends strongly on the initial magnetic field and on the compressibility of the turbulent driving. As a consequence, higher magnetic field in high column density environment may lower the energy necessary to sustain a turbulence sufficiently intense to regulate star formation.