3D-Herschel: Constraining Dust Emission with Panchromatic Modeling of 3D-HST Galaxies

TL;DR

This paper introduces 3D-Herschel, a comprehensive FIR catalog combined with panchromatic modeling of galaxies, revealing how dust properties and IR luminosities depend on stellar mass and redshift, and highlighting the importance of FIR data for accurate dust characterization.

Contribution

The study presents a new FIR catalog and demonstrates the impact of including Herschel FIR data in galaxy modeling, showing that FIR constraints significantly influence dust temperature and IR luminosity estimates.

Findings

FIR data improves dust temperature estimates by ~7K across redshifts.

UV-MIR models without FIR data can recover stellar properties accurately for most galaxies.

IR luminosity ratios vary with stellar mass, indicating mass-dependent MIR-to-IR conversions.

Abstract

We present 3D-Herschel, a new 0.3-350$\mu$m photometric catalog that combines deblended Herschel far-infrared (FIR) imaging with the CANDELS/3D-HST legacy fields to probe the dust-obscured universe. Using the 17-parameter fitting code Prospector-$\beta$, a Bayesian inference framework, we model 41,387 galaxies spanning 0.5 $< z <$ 2.5 to measure stellar and dust properties with realistic error bars. Comparing fits with and without FIR constraints, we find that for the 3.2$\%$ of galaxies with $>3 \sigma$ detections in at least two Herschel bands, UV-MIR-only models (0.3-24$\mu$m) recover robust stellar ages, SFRs, and stellar masses (50-70$\%$ within the median 1$\sigma$ error). Consequently, the star-forming sequence shows no systematic offset, with an average deviation of 0.1$\pm$0.07 dex at fixed stellar mass for FIR-detected sources at all redshifts. However, the use of rigid log-average IR templates with fixed dust emission parameters ($\gamma$, $U_{\mathrm{min}}$, $Q_{\mathrm{PAH}}$) in UV-MIR modeling corresponds to an unevolving MIR-to-IR luminosity ratio and cold dust temperatures. By contrast, fits that include Herschel photometry, with added freedom in the FIR, yield dust temperatures that are $\sim$7K warmer at all redshifts, with $\sim$0.2 dex higher IR-to-7.7$\mu$m luminosity ratios at the low-mass end of a Herschel-detected sample (log($M_{\star}$) $\sim$9.6 $M_{\odot}$). These results demonstrate that MIR-to-IR conversions depend on stellar mass, cautioning against $L_{\mathrm{IR}}$-independent templates without FIR data. For galaxies with $<10^{11} \ M_{\odot}$ at $z>1.5$, even with state-of-the-art analysis, Herschel can at best provide upper limits due to source confusion; next-generation FIR telescopes will be essential to fully characterize dust emission in distant galaxies.