Non-thermal cosmic backgrounds and prospects for future high-energy observations of blazars
We discuss the contribution of the blazar population to the extragalactic background radiation across the electromagnetic (e.m.) spectrum with particular reference to the microwave, hard-X-ray and γ-ray bands. Our estimates are based on a recently derived blazar radio LogN-LogS that was built by combining several radio and multi-frequency surveys. We show that blazar emission integrated over cosmic time gives rise to a considerable broad-band non-thermal cosmic background that dominates the extragalactic brightness in the high-energy part of the e.m. spectrum. We also estimate the number of blazars that are expected to be detected by future planned or hypothetical missions operating in the X-ray and γ-ray energy bands.
KeywordsGalaxies:active Galaxies: blazar: BL Lacertae surveys
Unable to display preview. Download preview PDF.
- 2.Blandford, R.D., Rees, M.J.: in: Pittsburgh Conference on BL Lac Objects, Wolfe, A.M. (ed.), University of Pittsburgh, Pittsburgh, p. 328 (1978)Google Scholar
- 3.Galbiati, E., Caccianiga, A., Maccacaro, T., et al.: A&A, in press, astro-ph/0410432 (2004)Google Scholar
- 11.Kappadath, S.C.: ph. D. Thesis, University of New Hampshire, USA (1998)Google Scholar
- 21.Peebles, P.: The large scale sturcture of the universe, in: Priceton, P.U.P. (ed.) (1980)Google Scholar
- 22.Perri, M., Giommi, P.: MNRAS 362, L61 (2000)Google Scholar