The reliability of infrared emission as a galaxy star formation rate tracer

Star formation is the most important process in the evolution of galaxies. Hence, to understand the galaxy population reliable star-formation rate indicators are needed. The most widespread tracer is infrared emission, since it is assumed that dust (from which the infrared emission originates) is mostly heated by young stellar populations. However, recent studies challenge this assumption, questioning the reliability of infrared emission as a star-formation tracer. We propose to investigate the spectral signatures and the contribution to dust heating of star-forming regions using state-of-the-art hydrodynamical simulations. These simulations model the entire star-formation complex in 3D, but do not simulate the emission and transport of radiation. We plan to apply the Monte Carlo radiative transfer code SKIRT to the hydrodynamical simulations and store the resulting spectra as emission templates for star-forming regions. Such templates already exist in the literature, but it has been shown that the underlying one-dimensional physical model is too simplistic and cannot reproduce luminosity functions and cosmic spectral energy distributions in the ultraviolet. We foresee to combine the updated templates with cosmological simulations to investigate the origin of current discrepancies in the ultraviolet, quantify the dust heating contribution of young stars, and recalibrate infrared emission as a common star-formation rate indicator.