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. [...] The standard SK between surface densities cold (neutral+molecular) gas rate simulated shows a steepening at low densities, starting from knee whose position depends on disc fraction: more gas-rich discs takes place higher densities. Because fraction metallicity are typically related, this environmental dependence mimics predictions models where H2 is modulated by metallicity. density which HI molecular equate can range ~10 up to 34 Msun/pc^2. As expected, using much smaller variations among simulations. find that pressure not well represented classical external vertical hydrostatic equilibrium. Instead fit expression P_fit = Sigma_cold sigma_cold kappa / 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. [Abridged]