Experimental Astronomy

, Volume 20, Issue 1–3, pp 31–40 | Cite as

Non-thermal cosmic backgrounds and prospects for future high-energy observations of blazars

  • P. GiommiEmail author
  • S. Colafrancesco
Original Article


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.


Galaxies:active Galaxies: blazar: BL Lacertae surveys 


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  1. 1.
    Aharonian, F.A., Akhperjanian, A.G., Barrio, J.A., et al.: APh 17, 459 (2002)ADSGoogle Scholar
  2. 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. 3.
    Galbiati, E., Caccianiga, A., Maccacaro, T., et al.: a&A, in press, astro-ph/0410432 (2004)Google Scholar
  4. 4.
    Giacconi, R., Gursky, H., Paolini, F., Rossi, B.: Phys. Rev. Lett. 9, 439 (1962)CrossRefADSGoogle Scholar
  5. 5.
    Giommi, P., Colafrancesco, S.: A&A 414, 7 (2004)CrossRefADSGoogle Scholar
  6. 6.
    Giommi, P., Menna, M.T., Padovani, P.: MNRAS 310, 465 (1999)CrossRefADSGoogle Scholar
  7. 7.
    Giommi, P., Colafrancesco, S., Cavazzuti, E., Perri, M., Pittori, C.: A&A 445, 843 (2006)CrossRefADSGoogle Scholar
  8. 8.
    Gonzales-Nuevo, J., Toffolatti, L., Argueso, F.: ApJ 621, 1 (2005)CrossRefADSGoogle Scholar
  9. 9.
    Gruber, D.E., Matteson, J.L., Peterson, L.E., Jung, G.V.: ApJ 520, 124 (1999)CrossRefADSGoogle Scholar
  10. 10.
    Hartman, R.C., Bertsch, D.L., Bloom, S.D., et al.: ApJS 123, 79 (1999)CrossRefADSGoogle Scholar
  11. 11.
    Kappadath, S.C.: ph. D. Thesis, University of New Hampshire, USA (1998)Google Scholar
  12. 12.
    Kushino, A., Ishisaki, Y., Morita, U., et al.: PASJ 54, 327 (2002)ADSGoogle Scholar
  13. 13.
    Loan, A.J., Wall, J., Lahav, O.: MNRAS 286, 994 (1997)ADSGoogle Scholar
  14. 14.
    Lumb, D.H., Warwick, R.S., Page, M., De Luca, A.: A&A 389, 93L (2002)CrossRefADSGoogle Scholar
  15. 15.
    Marshall, F.E., Boldt, E.A., Holt, S.S., et al.: ApJ 235, 4 (1980)CrossRefADSGoogle Scholar
  16. 16.
    Mather, J., Fixsen, D., Shafer, R.A., Mosier, C., Wilkinson, D.T.: ApJ 512, 511 (1999)CrossRefADSGoogle Scholar
  17. 17.
    Moretti, A., Campana, S., Lazzati, D., Tagliaferri, G.: ApJ 588, 696 (2003)CrossRefADSGoogle Scholar
  18. 18.
    Padovani, P., Ghisellini, G., Fabian, A., Celotti, A. MNRAS 260, L21 (1993)ADSGoogle Scholar
  19. 19.
    Padovani, P., Giommi, P.: ApJ 444, 567 (1995)CrossRefADSGoogle Scholar
  20. 20.
    Padovani, P., Perlman, E., Landt, H., Giommi, P., Perri, M.: ApJ 58, 128 (2003)CrossRefADSGoogle Scholar
  21. 21.
    Peebles, P.: The large scale sturcture of the universe, in: Priceton (ed.) P.U.P. (ed.)(1980)Google Scholar
  22. 22.
    Perri, M., Giommi, P.: MNRAS 362, L61 (2000)Google Scholar
  23. 23.
    Rector, T.A., Stocke, J.T., Perlman, E.S., Morris, S.L., Gioia, I.M.: AJ 120, 1626 (2000)CrossRefADSGoogle Scholar
  24. 24.
    Rosati, P., Tozzi, P., Giacconi, R., et al.: ApJ 566, 667 (2002)CrossRefADSGoogle Scholar
  25. 25.
    Scott, D., White, M.: A&A 346, 1 (1999)ADSGoogle Scholar
  26. 26.
    Sreekumar, P., Bertsch, D.L., Dingus, B.L., et al.: ApJ 494, 523 (1998)CrossRefADSGoogle Scholar
  27. 27.
    Strong, A., Moskalenko, I., Reimer, O.: ApJ 613, 956 (2004)CrossRefADSGoogle Scholar
  28. 28.
    Tegmark, M., Efstathiou, G.: MNRAS, 281, 1297 (1996)ADSGoogle Scholar
  29. 29.
    Toffolatti, L., Argueso Gomez, F., de Zotti, G., et al.: MNRAS 297, 117 (1998)CrossRefADSGoogle Scholar
  30. 30.
    Urry, C.M., Padovani, P.: PASP 107 803 (1995)CrossRefADSGoogle Scholar
  31. 31.
    Urry, C.M.: ASPC 290, 3 (2003)ADSGoogle Scholar
  32. 32.
    Vecchi, A., Molendi, S., Guainazzi, M., Fiore, F., Parmar, A.N.: A&A 349, L73 (1999)ADSGoogle Scholar
  33. 33.
    Vellieux, S.: ASPC 290, 11 (2003)ADSGoogle Scholar

Copyright information

© Springer Science + Business Media B.V. 2006

Authors and Affiliations

  1. 1.ASI Science Data Center, C/O ESA-ESRINFrascatiItaly
  2. 2.INAFOsservatorio Astronomico di RomaPalermoItaly

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