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| Paper: |
Infrared Properties of Low-Metallicity Galaxies |
| Volume: |
357, The Spitzer Space Telescope: New Views of the Cosmos |
| Page: |
215 |
| Authors: |
Engelbracht, C.W.; Gordon, K.D.; Misselt, K.; Smith, J.D.T.; Perez-Gonzalez, P.G.; Rieke, G.H.; Werner, M.W.; Vanzi, L.; Brandl, B.R. |
| Abstract: |
We present new Spitzer photometry of three low-metallicity galaxies. These galaxies have metallicities more than 30 times lower than the solar value and include the two galaxies with the lowest known metallicities, I Zw 18 and SBS 0335- 52. Our IRAC and MIPS data represent the first mid- to far-infrared detections for most of these galaxies and allow us for the first time to explore the range of infrared properties of extremely low metallicity galaxies as a class. We derive dust temperatures, dust masses, and optical/infrared luminosities of the galaxies. To put our sample of low-metallicity galaxies into context, we use infrared colors and spectra of galaxies over the full range of metallicities observed in local galaxies to show that there is a transition metallicity below which PAHs are not observed in galaxies. |
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