DirtyGrid II: An Analysis of the Dust and Stellar Properties in Nearby Star-forming Galaxies
Abstract
We study the dust and stellar properties of the Spitzer Infrared Nearby Galaxies Survey galaxies by fitting the ultraviolet (UV) to far-infrared (FIR) spectral energy distributions using the DIRTYGrid stellar and dust radiative transfer models. We find a minimum of two components of different stellar ages are needed, representing a young and an old stellar population, in order to obtain good fits for most of the galaxies. Our total dust masses agree with literature dust masses to within a factor of 2, and the residuals correlate most strongly with the stellar mass surface density of the old component. The LMC-2 dust grain model best describes the dust found in these normal star-forming galaxies. The derived attenuation curves are steeper than those found previously for starburst galaxies, and possess a weak 2175 Å feature. The relative contribution of the young and old stellar components as a function of wavelength reveals that the young component dominates the far-UV and MIPS24 bands, the old component dominates the optical/near-IR bands, and both components are important for the FIR bands. The DIRTYGrid star formation rates (SFRs) are consistent with a number of literature SFR indicators within a factor of 2. The differences we find are primarily due to the influence of the old stellar population that are accounted for by the DIRTYGrid SFRs fitting on a galaxy-by-galaxy basis using the information present in the full UV-FIR spectral energy distribution.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2021
- DOI:
- 10.3847/1538-4357/ac1427
- Bibcode:
- 2021ApJ...920...96L
- Keywords:
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- Interstellar dust;
- Spectral energy distribution;
- Radiative transfer;
- Galaxies;
- Star formation;
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