Rainó, S. and Bouvier, A. and Chen, A. W. and Razzaque, S. and Reimer, A. and Reyes, L. C. (2011) Fermi-LAT limits on the γ-ray opacity of the Universe. Il nuovo cimento C, 34 (3). pp. 253-256. ISSN 1826-9885
|
Text
ncc9926.pdf - Published Version Download (221kB) | Preview |
Abstract
The Fermi Large Area Telescope (LAT) has provided us with a rich sample of extragalactic sources, among which γ-ray blazars with redshift up to z ∼ 3 and Gamma-Ray Bursts with redshift up to z ∼ 4.3, that we have used to probe the interaction via pair production of γ-ray photons above 10GeV with low-energy photons from the Extragalactic Background Light (EBL). The EBL from the infrared to the ultraviolet is difficult to measure directly, but can be constrained with a variety of methods. In this paper we report the method applied to evaluate the EBL attenuation of γ-ray fluxes by comparing the measured energy spectrum of the source and the unabsorbed spectrum above 10 GeV. We place upper limits on the γ-ray opacity of the Universe at various energies and redshifts, and compare this with predictions from well-known EBL models. We find that EBL intensities at optical-UV wavelengths as large as those predicted by the “baseline” and “fast evolution” models can be ruled out with high confidence. The ensuing upper limits to the EBL opacity are presented.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | γ-ray ; X- and γ-ray instruments |
| Subjects: | 500 Scienze naturali e Matematica > 530 Fisica |
| Depositing User: | Marina Spanti |
| Date Deposited: | 06 Apr 2020 18:46 |
| Last Modified: | 06 Apr 2020 18:46 |
| URI: | http://eprints.bice.rm.cnr.it/id/eprint/17279 |
Actions (login required)
 |
View Item |
