MODELING THE EXTRAGALACTIC BACKGROUND LIGHT FROM STARS AND DUST

Extragalactic Background Light

First stars and the extragalactic background light: How recent γ-ray observations constrain the early universe

Context. The formation of the first stars marks the end of the dark ages of the universe, a subject of lively scientific debate. Not (yet) accessible to direct observations, this early stage of the universe is mostly studied via theoretical calculations and numerical simulations. An indirect window is provided by integrated present day observables such as the metal abundance or the diffuse extr...

Extragalactic background light measurements and applications

This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiaca...

Blazar Gamma-rays, Shock Acceleration, and the Extragalactic Background Light

The observed spectra of blazars, their intrinsic emission, and the underlying populations of radiating particles are intimately related. The use of these sources as probes of the extragalactic infrared background, a prospect propelled by recent advances in TeV-band telescopes, soon to be augmented by observations by NASA’s upcoming Gamma-Ray Large Area Space Telescope (GLAST), has been a topic ...

The Cosmic near Infrared Background: Remnant Light from Early Stars

The redshifted ultraviolet light from early stars at z ∼ 10 contributes to the cosmic near infrared background. We present detailed calculations of its spectrum with various assumptions about metallicity and mass spectrum of early stars. We show that if the near infrared background has a stellar origin, metal-free stars are not the only explanation of the excess near infrared background; stars ...