A Complete 16 micron-Selected Galaxy Sample at $z\sim1$: Mid-infrared
  Spectral Energy Distributions
  We describe a complete, flux-density-limited sample of galaxies at redshift
$0.8 < z < 1.3$ selected at 16 micron. At the selection wavelength near 8
micron rest, the observed emission comes both from dust heated by intense star
formation and from active galactic nuclei (AGNs). Fitting the spectral energy
distributions (SEDs) of the sample galaxies to local-galaxy templates reveals
that more than half the galaxies have SEDs dominated by star formation. About
one sixth of the galaxy SEDs are dominated by an AGN, and nearly all the rest
of the SEDs are composite. Comparison with X-ray and far-infrared observations
shows that combinations of luminosities at rest-frame 4.5 and 8 micron give
good measures of both AGN luminosity and star-formation rate. The sample
galaxies mostly follow the established star-forming main sequence for $z=1$
galaxies, but of the galaxies more than 0.5 dex above that main sequence, more
than half have AGN-type SEDs. Similarly, the most luminous AGNs tend to have
higher star-formation rates than the main sequence value. Galaxies with stellar
masses $>$10$^{11}$\,\Msun\ are unlikely to host an AGN. About 1% of the sample
galaxies show an SED with dust emission typical of neither star formation nor
an AGN.
