'Astronomical Society of the Pacific Conference Series'
Abstract
In this paper, I have attempted to highlight key results from deep extragalactic surveys at mid-infrared wavelengths. I discuss advances in our understanding of dust enshrouded star-formation and AGN activity at 0 3 will become possible only with future facilities like ALMA. Currently, the presence of dust can only be assessed in a small fraction of the youngest starbursts at z > 5 by looking for redshifted large equivalent width Hα emission in broadband filters like the IRAC 4.5μm passband. Hα to UV ratios in these objects are a tracer of dust extinction and measuring this ratio in GOODS galaxies indicate dust in ~20% of star-forming galaxies at z > 5. Finally, implications for reionization based on the measured stellar mass density and star-formation rates of galaxies at these redshifts are discussed
