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 LITTLETHINGS survey are considered, with deep Herschel PACS and SPIRE observations at 100 μm, 160 μm, 250 μm, 350 μm, and 500 μm. 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 LTIR and Mdust regimes seen among these samples. Dust-to-gas mass ratios of ∼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.
@article{arxiv.2104.14599,
title = {$\textit{Herschel}$ Photometric Observations of $\mathrm{L{\small{ITTLE}}}$ $\mathrm{T{\small{HINGS}}}$ Dwarf Galaxies},
author = {Phil Cigan and Lisa M. Young and Haley L. Gomez and Suzanne C. Madden and Pieter De Vis and Deidre A. Hunter and Bruce G. Elmegreen and Elias Brinks},
journal= {arXiv preprint arXiv:2104.14599},
year = {2022}
}
Comments
26 pages, 19 figures. To be published in The Astronomical Journal