Schmidt–Kennicutt relations in SPH simulations of disc galaxies with effective thermal feedback from supernovae

摘要: We study several versions of the Schmidt-Kennicutt (SK) relation obtained for isolated spiral galaxies in TreeSPH simulations run with GADGET3 code including novel MUlti-Phase Particle Integrator (MUPPI) algorithm star formation and stellar feedback. This is based on a sub-resolution multi-phase treatment gas particles, where explicitly related to molecular gas, fraction phase computed from hydrodynamical pressure, following phenomenological correlation. No chemical evolution included this version code. The standard SK between surface densities cold (neutral+molecular) rate simulated shows steepening at low densities, starting knee whose position depends disc fraction: more gas-rich discs takes place higher densities. Because metallicity are typically related, environmental dependence mimics predictions models H2 modulated by metallicity. density which HI equate can range 10 up 34 M pc 2 . As expected, using much smaller variations among simulations. find that pressure not well represented classical external vertical hydrostatic equilibrium. Instead fit expression Pt = cold= 6, three quantities right-hand side density, velocity dispersion epicyclic frequency. When “dynamical” relation, i.e. uses divided orbital time, considered, we all our stay same relation. interpret as manifestation equilibrium energy injection dissipation stationary galaxy discs, when energetic feedback effective given above. These findings further support idea realistic model structure should take into account SNe.