Comprehensive comparison of models for spectral energy distributions from 0.1 micron to 1 mm of nearby star-forming galaxies

TL;DR

This study compares three spectral energy distribution models applied to 61 nearby star-forming galaxies, analyzing their consistency and differences in estimating key physical properties across a broad wavelength range.

Contribution

It provides a comprehensive comparison of SED-fitting models (CIGALE, GRASIL, MAGPHYS) and introduces new SED-based formulas for estimating stellar mass from WISE data.

Findings

All models fit observed SEDs well and agree on key physical quantities.

Different models diverge significantly in the mid-infrared regime.

SFR estimates vary for galaxies with low specific SFR.

Abstract

We have fit the far-ultraviolet (FUV) to sub-millimeter (850 micron) spectral energy distributions (SEDs) of the 61 galaxies from the "Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel" (KINGFISH). The fitting has been performed using three models: the Code for Investigating GALaxy Evolution (CIGALE), the GRAphite-SILicate approach (GRASIL), and the Multi-wavelength Analysis of Galaxy PHYSical properties (MAGPHYS). We have analyzed the results of the three codes in terms of the SED shapes, and by comparing the derived quantities with simple "recipes" for stellar mass (Mstar), star-formation rate (SFR), dust mass (Mdust), and monochromatic luminosities. Although the algorithms rely on different assumptions for star-formation history, dust attenuation and dust reprocessing, they all well approximate the observed SEDs and are in generally good agreement for the associated quantities. However, the three codes show very different behavior in the mid-infrared regime, in particular between 25 and 70 micron where there are no observational constraints for the KINGFISH sample. We find that different algorithms give discordant SFR estimates for galaxies with low specific SFR, and that the standard "recipes" for calculating FUV absorption overestimate the extinction compared to the SED-fitting results. Results also suggest that assuming a "standard" constant stellar mass-to-light ratio overestimates Mstar relative to the SED fitting, and we provide new SED-based formulations for estimating Mstar from WISE W1 (3.4 micron) luminosities and colors. From a Principal Component Analysis of Mstar, SFR, Mdust, and O/H, we reproduce previous scaling relations among Mstar, SFR, and O/H, and find that Mdust can be predicted to within roughly 0.3 dex using only Mstar and SFR.