Extragalactic background light inferred from AEGIS galaxy SED-type fractions

Abstract

The extragalactic background light (EBL) is of fundamental importance both for understanding the entire process of galaxy evolution and for gamma-ray astronomy. However, the overall spectrum of the EBL between 0.1 and 1000 microns has never been determined directly neither from observed luminosity functions (LFs), over a wide redshift range, nor from any multiwavelength observation of galaxy spectral energy distributions (SEDs). The evolving, overall spectrum of the EBL is derived here utilizing a novel method based on observations only. The changing fractions of quiescent galaxies, star-forming galaxies, starburst galaxies and active galactic nucleus (AGN) galaxies from redshift 0.2 to 1 are estimated, and two alternative extrapolations of SED types to higher redshifts are considered. This allows calculation of the evolving EBL. The EBL uncertainties in our modelling based directly on the data are quantified, and their consequences for attenuation of very-high-energy gamma-rays due to pair production on the EBL are discussed. It is concluded that the EBL seems well constrained from the UV to the mid-IR at an intensity level roughly matching galaxy count data. Independent efforts from IR and gamma-ray astronomy are needed in order to reduce the uncertainties in the far-IR.

Contributed talk to the 25th Texas Symposium on Relativistic Astrophysics, Heidelberg December 6-10, 2010; 8 pages, 3 figures. Online material available at http://side.iaa.es/EBL

Cited by in corpus (9)

• A very-high-energy component deep in the Gamma-ray Burst afterglow
• Observation of inverse Compton emission from a long $\gamma$-ray burst
• Dark Matter and Fundamental Physics with the Cherenkov Telescope Array
• The nature of the Diffuse Gamma-Ray Background
• Sensitivity of the Cherenkov Telescope Array to the detection of axion-like particles at high gamma-ray opacities
• Production and propagation of ultra-high energy photons using CRPropa 3
• Probing $\mu$eV ALPs with future LHAASO observation of AGN $\gamma$-ray spectra
• Fireballs from Superconducting Cosmic Strings
• The TeV Blazar Measurement of the Extragalactic Background Light