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The relation between infrared excess (IRX) and UV spectral slope ($beta_{rm UV}$) is an empirical probe of dust properties of galaxies. The shape, scatter, and redshift evolution of this relation are not well understood, however, leading to uncertainties in estimating the dust content and star formation rates (SFRs) of galaxies at high redshift. In this study, we explore the nature and properties of the IRX-$beta_{rm UV}$ relation with a sample of $z=2-6$ galaxies ($M_*approx 10^9-10^{12},M_odot$) extracted from high-resolution cosmological simulations (MassiveFIRE) of the Feedback in Realistic Environments (FIRE) project. The galaxies in our sample show an IRX-$beta_{rm UV}$ relation that is in good agreement with the observed relation in nearby galaxies. IRX is tightly coupled to the UV optical depth, and is mainly determined by the dust-to-star geometry instead of total dust mass, while $beta_{rm UV}$ is set both by stellar properties, UV optical depth, and the dust extinction law. Overall, much of the scatter in the IRX-$beta_{rm UV}$ relation of our sample is found to be driven by variations of the intrinsic UV spectral slope. We further assess how the IRX-$beta_{rm UV}$ relation depends on viewing direction, dust-to-metal ratio, birth-cloud structures, and the dust extinction law and we present a simple model that encapsulates most of the found dependencies. Consequently, we argue that the reported `deficit of the infrared/sub-millimetre bright objects at $z>5$ does not necessarily imply a non-standard dust extinction law at those epochs.
We study the relationship between the UV continuum slope and infrared excess (IRX$equiv L_{rm IR}/L_{rm FUV}$) predicted by performing dust radiative transfer on a suite of hydrodynamical simulations of galaxies. Our suite includes both isolated disk
We use a sample of 4178 Lyman break galaxies (LBGs) at z = 3, 4 and 5 in the UKIRT Infrared Deep Sky Survey (UKIDSS) Ultra Deep Survey (UDS) field to investigate the relationship between the observed slope of the stellar continuum emission in the ult
We utilise a series of high-resolution cosmological zoom simulations of galaxy formation to investigate the relationship between the ultraviolet (UV) slope, beta, and the ratio of the infrared luminosity to UV luminosity (IRX) in the spectral energy
We use a sample of star-forming field and protocluster galaxies at z=2.0-2.5 with Keck/MOSFIRE K-band spectra, a wealth of rest-frame UV photometry, and Spitzer/MIPS and Herschel/PACS observations, to dissect the relation between the ratio of IR to U
Our research on the age-metallicity and mass-metallicity relations of galaxies is presented and compared to the most recent investigations in the field. We have been able to measure oxygen abundances using the direct method for objects spanning four