High redshift composite SEDs for AGN and star-forming galaxies


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Here we make publicly available our composite spectral energy distribution (SED) templates for AGN and star-forming galaxies. The creation of our empirical SEDs is described in detail Kirkpatrick et al. 2012, ApJ, 759, 139 - please cite this paper when using these templates.

We have a sample of 151 high redshift galaxies (z > 0.5) that were selected at 24 μm (80% have S24 > 200 μJy) for which we have Spitzer mid-IR spectroscopy and deep Herschel far-IR/submm imaging. We performed spectral decomposition on the IRS spectra and classified our sources as AGN or star-formation (SF) dominated based on whether the mid-IR spectrum was dominated by a power-law or PAH template. We further classified our sources into four subsamples: z~1 SF sources; z~2 SF sources; AGN with clear 9.7 μm silicate absorption; and AGN with featureless mid-IR spectra.

Within our subsamples, we created composite SEDs by stacking near-IR and mid-IR photometry and spectroscopy; in the far-IR, we fit a two temperature modified blackbody to the data. For the SF subsamples, we lack data in the range ~18-30 μm, so we have filled in that wavelength range by either extending the warm component of the two-temperature modified blackbody or linearly interpolating. Since we did not formally fit any data in this range, and this portion of the spectrum is for illustrative purposes only, we list the associated errors as 0.

Please contact Allison Kirkpatrick (kirkpatr AT astro.umass.edu) if you have any questions about these SED templates.
z~1 SF SED
z~2 SF SED
Silicate AGN SED
Featureless AGN SED