非表示:
キーワード:
Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO
MPINP:
Infrarot-Astrophysik - Abteilung Hofmann
要旨:
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.
