English

An infrared background--TeV gamma-ray crisis?

Astrophysics 2009-10-31 v3 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology

Abstract

We consider the implications of the recent determination of the universal infrared background for the propagation of photons up to 20 TeV from the active galaxy Markarian 501 as observed by HEGRA. At 20 TeV the mean free path for photon-photon collisions on the infrared background would be much shorter than the distance to Markarian 501, implying absorption factors of the order of exp(-10), or greater, and consequently an excessive power output for this active galaxy. Possible solutions of this problem are discussed.

Cite

@article{arxiv.astro-ph/0005349,
  title  = {An infrared background--TeV gamma-ray crisis?},
  author = {R. J. Protheroe and H. Meyer},
  journal= {arXiv preprint arXiv:astro-ph/0005349},
  year   = {2009}
}

Comments

12 pages, 4 figures, Accepted for publication in Physics Letters B. Minor changes

R2 v1 2026-07-22T07:47:04.945Z