Strategies for Obtaining Robust Spectral Energy Distribution Fitting Parameters for Galaxies at z ∼ 1 and z ∼ 2 in the Absence of Infrared Data

• Published in: The Astrophysical journal 2024-02, Vol.962 (1), p.59
• Main Authors: Osborne, Chandler, Salim, Samir
• Format: Article
• Language: English
• Subjects: Astronomical models; Attenuation; Dust; Galaxies; Galaxy distribution; Galaxy evolution; Galaxy formation; Galaxy masses; Galaxy properties; High-redshift galaxies; Infrared photometry; Luminosity; Metallicity; Model selection; Near infrared radiation; Parameters; Robustness; Spectral energy distribution; Star & galaxy formation; Star formation; Stars; Stellar models; Stellar populations
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ad17c8

Robust estimation of star formation rates (SFRs) at higher redshifts ( z ≳ 1) using UV–optical–near-infrared (NIR) photometry is contingent on the ability of spectral energy distribution (SED) fitting to constrain the dust attenuation, stellar metallicity, and star formation history (SFH) simultaneously. IR-derived dust luminosities can help break the degeneracy between these parameters, but IR data are often not available. Here, we explore strategies for SED fitting at z ≳ 1 in the absence of IR data using a sample of log M * > 10.2 star-forming galaxies from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) for which 24 μ m data are available. We adopt the total IR luminosity ( L TIR ) obtained from 24 μ m as the “ground truth,” which allows us to assess how well it can be recovered (as L dust ) from UV–optical–NIR SED fitting. We test a variety of dust attenuation models, stellar population synthesis models, metallicity assumptions, and SFHs separately to identify which assumptions maximize the agreement (correlation and linearity) between L TIR and L dust . We find that a flexible dust attenuation law performs best. For stellar populations, we find that Bruzual & Charlot models are favored over those of Eldridge et al. Fixing the stellar metallicity at solar value is preferred to other fixed values or leaving it as a free parameter. For SFHs, we find that minimizing the variability in the recent ( 8 and 0.7 < z < 1.3, obtained using the models we found to be the most robust.