English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In star-forming galaxies, the far-infrared (FIR) and radio-continuumluminosities obey a tight empirical relation over a large range ofstar-formation rates (SFR). We examine magneto-hydrodynamic galaxy simulationswith cosmic rays (CRs), accounting for their advective and anisotropicdiffusive transport. We show that gravitational collapse of the proto-galaxygenerates a corrugated accretion shock, which injects turbulence and drives asmall-scale magnetic dynamo. As the shock propagates outwards and theassociated turbulence decays, the large velocity shear between thesupersonically rotating cool disc with respect to the (partially)pressure-supported hot circumgalactic medium excites Kelvin-Helmholtz surfaceand body modes. Those inject turbulence and drive multiple small-scale dynamos,which exponentially amplify magnetic fields. They grow in scale to reachequipartition with thermal and CR energies in Milky Way-mass galaxies. In smallgalaxies, the magnetic energy saturates at the turbulent energy while it failsto reach equipartition with thermal and CR energies. We solve for steady-statespectra of CR protons, secondary electrons/positrons from hadronic CR-protoninteractions with the interstellar medium, and primary shock-acceleratedelectrons at supernovae. The radio-synchrotron emission is dominated by primaryelectrons, irradiates the magnetised disc, bulge, and bubble-shapedmagnetically-loaded outflows of our simulated Milky Way-mass galaxy. Ourstar-forming and star-bursting galaxies with saturated magnetic fields matchthe global FIR-radio correlation (FRC) across four orders of magnitude. Itsintrinsic scatter arises due to (i) different magnetic saturation levels thatresult from different seed magnetic fields, (ii) different radio synchrotronluminosities for different specific SFRs at fixed SFR and (iii) a varying radiointensity with galactic inclination. (abridged)

Simulating radio synchrotron emission in star-forming galaxies: small-scale magnetic dynamo and the origin of the far infrared-radio correlation