Extragalactic background light and gamma-ray attenuation

Joel R. Primack, Alberto Domínguez, Rudy C. Gilmore, Rachel S. Somerville

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Scopus citations


Data from (non-) attenuation of gamma rays from active galactic nuclei (AGN) and gamma ray bursts (GRBs) give upper limits on the extragalactic background light (EBL) from the UV to the mid-IR that are only a little above the lower limits from observed galaxies. These upper limits now rule out some EBL models and purported observations, with improved data likely to provide even stronger constraints. We present EBL calculations both based on multiwavelength observations of thousands of galaxies and also based on semi-analytic models, and show that they are consistent with these lower limits from observed galaxies and with the gamma-ray upper limit constraints. Such comparisons "close the loop" on cosmological galaxy formation models, since they account for all the light, including that from galaxies too faint to see. We compare our results with those of other recent works, and discuss the implications of these new EBL calculations for gamma ray attenuation. Catching a few GRBs with ground-based atmospheric Cherenkov Telescope (ACT) arrays or water Cherenkov detectors could provide important new constraints on the high-redshift star formation history of the universe.

Original languageEnglish (US)
Title of host publication25th Texas Symposium on Relativistic Astrophysics, TEXAS 2010
Number of pages12
StatePublished - 2011
Event25th Texas Symposium on Relativistic Astrophysics, TEXAS 2010 - Heidelberg, Germany
Duration: Dec 6 2010Dec 10 2010

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


Other25th Texas Symposium on Relativistic Astrophysics, TEXAS 2010

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)


  • Luminosity density
  • extragalactic background light
  • galaxy spectral energy evolution
  • gamma ray attenuation
  • semi-analytic models of the evolving galaxy population


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