Global dynamics of the interstellar medium in magnetized disc galaxies

摘要: Magnetic fields are an elemental part of the interstellar medium in galaxies. However, their impact on gas dynamics and star formation galaxies remains controversial. We use a suite global magnetohydrodynamical simulations isolated disc to study influence magnetic diffuse dense discs. find that field acts multiple ways. Stronger magnetised discs fragment earlier due shorter growth time Parker instability. Due instability we also cold ($T<50\,\mathrm{K}$) ($n\sim10^3-10^4\,\mathrm{cm}^{-3}$) several hundred pc above/below midplane without any form stellar feedback. In addition, change fragmentation pattern. While hydrodynamical case, breaks up into ring-like structures, show filamentary entities extent both azimuthal radial direction. These kpc scale filaments become magnetically (super-)critical very quickly allow for rapid massive giant molecular clouds. Our suggest major differences behaviour - varying magnetisation could arise.