AEGIS: Infrared Spectral Energy Distributions of MIPS 70 μm-selected Sources

Abstract

We present 0.5-160 μm spectral energy distributions (SEDs) of galaxies, detected at 70 μm with the Multiband Imaging Photometer for Spitzer (MIPS), using broadband imaging data from Spitzer and ground-based telescopes. Spectroscopic redshifts, in the range 0.2 ≤ z ≤ 1.5, have been measured as part of the Deep Extragalactic Evolutionary Probe 2 (DEEP2) project. On the basis of the SEDs, we explore the nature and physical properties of the sources. Using the optical spectra, we derive Hβ and [O II]-based star formation rates (SFRs) that are 10-100 times lower than SFR estimates based on IR and radio. The median offset in SFR between optical and IR is reduced by a factor of ~3 when we apply a typical extinction correction. We investigate mid- to far-infrared correlations for low-redshift (>0.5) and high-redshift (0.5 < z < 1.2) bins. Using this unique "far-infrared"-selected sample, we derive an empirical mid- to far-infrared relationship that can be used to estimate the infrared energy budget of galaxies in the high-redshift universe. Our sample can be used as a template to translate far-infrared luminosities into bolometric luminosities for high-redshift objects.