Dust attenuation, dust emission, and dust temperature in galaxies at z>=5: a view from the FIRE-2 simulations

Understand

We present a suite of 34 high-resolution cosmological zoom-in simulations consisting of thousands of halos up to M_halo~10^12 M_sun (M_star~10^10.5 M_sun) at z>=5 from the Feedback in Realistic Environments project.

• We post-process our simulations with a three-dimensional Monte Carlo dust radiative transfer code to study dust extinction, dust emission, and dust temperature within these simulated z>=5 galaxies.
• Our sample forms a tight correlation between infrared excess (IRX=F_IR/F_UV) and ultraviolet (UV)-continuum slope (beta_UV), despite the patchy, clumpy dust geometry shown in our simulations.
• We find that the IRX-beta_UV relation is mainly determined by the shape of the extinction curve and is independent of its normalization (set by the dust-to-gas ratio).