Measurement of the EBL spectral energy distribution using the VHE $\gamma$-ray spectra of H.E.S.S. blazars
Langue
en
Article de revue
Ce document a été publié dans
Astronomy and Astrophysics - A&A. 2017, vol. 606, p. A59
EDP Sciences
Résumé en anglais
Very high-energy γ rays (VHE, E ≳ 100 GeV) propagating over cosmological distances can interact with the low-energy photons of the extragalactic background light (EBL) and produce electron-positron pairs. The transparency ...Lire la suite >
Very high-energy γ rays (VHE, E ≳ 100 GeV) propagating over cosmological distances can interact with the low-energy photons of the extragalactic background light (EBL) and produce electron-positron pairs. The transparency of the Universe to VHE γ rays is then directly related to the spectral energy distribution (SED) of the EBL. The observation of features in the VHE energy spectra of extragalactic sources allows the EBL to be measured, which otherwise is very difficult. An EBL model-independent measurement of the EBL SED with the H.E.S.S. array of Cherenkov telescopes is presented. It was obtained by extracting the EBL absorption signal from the reanalysis of high-quality spectra of blazars. From H.E.S.S. data alone the EBL signature is detected at a significance of 9.5σ, and the intensity of the EBL obtained in different spectral bands is presented together with the associated γ-ray horizon. Key words: gamma rays: galaxies / BL Lacertae objects: general / cosmic background radiation / infrared: diffuse background† Deceased.⋆ Corresponding authors: H.E.S.S. Collaboration, e-mail: contact.hess@hess-experiment.eu< Réduire
Mots clés en anglais
Gamma rays: galaxies — Cosmology: cosmic background radiation Send offprint requests to: HESS collaboration
gamma rays: galaxies
BL Lacertae objects: general
cosmic background radiation
infrared: diffuse background
gamma ray: VHE
blazar: spectrum
spectral
HESS
electron positron
Cherenkov counter
energy spectrum
transparency
absorption
background
signature
horizon
photon
propagation
Origine
Importé de halUnités de recherche