Modeling the Origins of Galaxy Dust Attenuation Laws Using Simulated Data
Abu Ala An-Nadwi (a*), Revaniza Adhistyani (a), Praneeta Bhojwani (a), Dian P. Triani (b)

a) Astronomy Study Program, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10 Bandung, Indonesia
*abuannadwi[at]gmail.com
b) Center for Astrophysics Harvard & Smithshonian, 60 Garden Street, Cambridge, Massachusetts 02138, USA

Abstract

We investigated the physical origins of galaxy dust attenuation laws by combining a flexible toy attenuation model with predictions from cosmological simulations. Building on the framework of Maheson et al. (2025), we constructed models that vary key parameters--specifically the optical depths of the birth-cloud and ISM dust, \(\tau_1\) and \(\tau_2\), the slope of the attenuation law, \(n_2\), and the fraction of young stars, \(f_{10}\). These parameters allow the model to produce a diverse set of attenuation curves, capturing variations in total attenuation, slope \(\,A_{\mathrm{UV}}/A_V\), and UV bump strength. To connect these models with realistic galaxy populations, we analyzed mock galaxy catalogs from the semi-analytic model Dusty SAGE, which self-consistently tracks the evolution of dust mass, stellar populations, and star formation across cosmic time. The resulting attenuation laws were compared with galaxy properties including dust mass, metallicity, stellar mass, and star formation rate. We find that \(A_V\) is strongly correlated with stellar mass, and shows a tentative correlation with star formation rate (the latter is less robust due to statistical uncertainties). This approach aims to uncover the key drivers of dust attenuation law diversity and to inform improved dust modeling.

Keywords: Dust attenuation- Galaxy evolution- Cosmological simulations

Topic: Galaxies and Cosmology