Galaxies may have been extremely metal poor just after their birth, and hence they may have had only a small amount of dust. In such galaxies, SNe II dominate dust formation. The size of dust grains formed in SNe II cannot be so large (Todini & Ferrara 2001), and host galaxies are so young that grain growth in interstellar space and formation by evolved low-mass stars cannot be effective. The size and amount of the small grains largely affects the typical wavelength and luminosity of infrared (IR) radiation from young galaxies. We construct a model to calculate the evolution of dust content and the IR SED of low metallicity, extremely young galaxies. Because of their low metallicity and active star formation, blue compact dwarf galaxies (BCDs) may be viable candidates for nearby primeval systems. We have focused on the evolution of dust content in one of these, SBS 0335-052, that has an unusual IR SED with strong flux at MIR in spite of its low metallicity (1/41 Z☉). We found that the MIR--FIR SED of SBS 0335-052 observed by ISO is consistent with a very young starburst that has the age of several × 106 yr and compact size with a radius of 20 pc. This indicates that both of MIR and FIR surveys are necessary to examine the dust amount of galaxies with a wide range of metallicity. We will also mention the prospects for ASTRO-F FIR survey on this subject.
8th Asian-Pacific Regional Meeting, Volume II
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