A Dust Attenuation Model Inspired by the NIHAO-SKIRT-Catalog

Abstract We use simulated attenuation curves from the NIHAO-SKIRT-Catalog to test the flexibility of commonly used dust attenuation models in the face of the variations expected from realistic star–dust geometries. Motivated by lack of flexibility in these existing models, we propose a novel dust attenuation model with three free parameters that can accurately recover the simulated attenuation curves as well as the best-fitting curves from the commonly used models. This new model is fully analytic and treats all starlight equally, in contrast to two-component dust attenuation models. We use the parameterization to investigate the relationship between the overall attenuation law shape and the strength of the 2175 Å bump. Our results indicate variation in star–dust geometry leads these features to correlate tightly, with grayer attenuation curves having weaker bumps.