DustPedia and Local Volume Legacy samples as benchmarks for dust evolution in galaxies

Aims. DustPedia and Local Volume Legacy (LVL) are two samples representative of the local galaxy population, including in total ∼1000 unique objects of all morphological types, with a wide range of stellar masses and star formation activity, and a spectral coverage from the ultraviolet to the far-infrared. The purpose of this work is to show that these samples cover two complementary ranges in stellar mass and galaxy morphology, making them an ideal set for constraining the dominant processes in the evolution of the galactic dust content.

Methods. Using the multi-wavelength data provided by the two surveys, we fitted the galaxies’ spectral energy distribution and estimated their physical properties, in particular the stellar mass, M_*, the specific dust mass, sM_dust = M_dust/M_*, and the specific star formation rate, sSFR = SFR/M_*.

Results. By combining DustPedia and LVL, we highlight that the trend of log₁₀(sM_dust) with log₁₀(M_*) is not monotonic. Thanks to a large number of objects across a wide range of M_*, we have been able to fit two smoothly joined linear correlations: a positive one for log₁₀(M_*/M_⊙)≲9.5 (a range populated mostly by LVL late spirals and irregulars), and a negative one for larger-mass, mainly DustPedia, spirals (with early-type galaxies being distinct and more dispersed in the same mass regime). For log₁₀(M_*/M_⊙) > 9.5, we confirm a strong correlation between sM_dust and sSFR; dwarf galaxies, instead, lie below this trend, showing a large scatter of sM_dust for −10.5 < log₁₀(sSFR/yr⁻¹) <  − 9.0. By using chemical evolution models we find that the observed log₁₀(sM_dust)–log₁₀(M_*) and log₁₀(sM_dust)–log₁₀(sSFR) trends can be interpreted mainly by variations in the initial gas mass budget and the galaxy ages, respectively. Low-mass Sm-Irr galaxies with low sM_dust and a high sSFR can only be reproduced by the models by assuming a highly efficient photofragmentation rate of large grains, and/or low grain growth in clouds.