Herschel Photometric Observations of Little Things Dwarf Galaxies

We present here far-infrared photometry of galaxies in a sample that is relatively unexplored at these wavelengths: low-metallicity dwarf galaxies with moderate star formation rates. Four dwarf irregular galaxies from the Little Things survey are considered, with deep Herschel PACS and SPIRE observations at 100, 160, 250, 350, and 500 mu m. Results from modified blackbody fits indicate that these galaxies have low dust masses and cooler dust temperatures than more actively star-forming dwarfs, occupying the lowest L (TIR) and M (dust) regimes seen among these samples. Dust-to-gas mass ratios of similar to 10(-5) are lower, overall, than in more massive and active galaxies but are roughly consistent with the broken power-law relation between the dust-to-gas ratio and metallicity found for other low-metallicity systems. Chemical evolution modeling suggests that these dwarf galaxies are likely forming very little dust via stars or grain growth and have very high dust destruction rates.

Automated summary

The study investigates the far-infrared photometry of low-metallicity dwarf galaxies with moderate star formation rates, finding that they have low dust masses and cooler dust temperatures with low dust-to-gas mass ratios. These galaxies are likely forming very little dust via stars or grain growth and have very high dust destruction rates.