Galaxy And Mass Assembly (GAMA): The 0.013 < z < 0.1 cosmic spectral energy distribution from 0.1 micron to 1mm

TL;DR

This study constructs the cosmic spectral energy distribution of low-redshift galaxies using multi-wavelength data, revealing the energy output and dust reprocessing in the nearby Universe with high precision.

Contribution

It provides the first well-constrained, dust-corrected cosmic spectral energy distribution from 0.1 micron to 1mm at low redshift, combining multiple surveys and addressing cosmic variance.

Findings

The Universe's energy output is approximately 1.8 x 10^{35} h W Mpc^{-3}.

Dust reprocesses about one-third of the emitted energy into the far-infrared.

The predicted IR emission matches observed data, validating the dust correction model.

Abstract

We use the GAMA I dataset combined with GALEX, SDSS and UKIDSS imaging to construct the low-redshift (z<0.1) galaxy luminosity functions in FUV, NUV, ugriz, and YJHK bands from within a single well constrained volume of 3.4 x 10^5 (Mpc/h)^{3}. The derived luminosity distributions are normalised to the SDSS DR7 main survey to reduce the estimated cosmic variance to the 5 per cent level. The data are used to construct the cosmic spectral energy distribution (CSED) from 0.1 to 2.1 \mum free from any wavelength dependent cosmic variance for both the elliptical and non-elliptical populations. The two populations exhibit dramatically different CSEDs as expected for a predominantly old and young population respectively. Using the Driver et al. (2008) prescription for the azimuthally averaged photon escape fraction, the non-ellipticals are corrected for the impact of dust attenuation and the combined CSED constructed. The final results show that the Universe is currently generating (1.8 +/- 0.3) x 10^{35} h W Mpc^{-3} of which (1.2 +/- 0.1) x 10^{35} h W Mpc^{-3} is directly released into the inter-galactic medium and (0.6 +/- 0.1) x 10^{35} h W Mpc^{-3} is reprocessed and reradiated by dust in the far-IR. Using the GAMA data and our dust model we predict the mid and far-IR emission which agrees remarkably well with available data. We therefore provide a robust description of the pre- and post dust attenuated energy output of the nearby Universe from 0.1micron to 0.6mm. The largest uncertainty in this measurement lies in the mid and far-IR bands stemming from the dust attenuation correction and its currently poorly constrained dependence on environment, stellar mass, and morphology.