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Infrared surveys provide essential insights on galaxy evolution. If near-IR studies suggest mild evolution of stellar populations with cosmic time, indications of a substantial evolution have been seen in the far-IR, although the available…

Astrophysics · Physics 2016-08-30 G. DeZotti , A. Franceschini , P. Mazzei , L. Granato , L. Danese

The Universe is largely transparent to $\gamma$ rays in the GeV energy range, making these high-energy photons valuable for exploring energetic processes in the cosmos. After seven years of operation, the Fermi {\it Gamma-ray Space…

High Energy Astrophysical Phenomena · Physics 2016-01-20 F. Massaro , D. J. Thompson , E. C. Ferrara

TeV gamma rays emitted by GRBs are converted into electron-positron pairs via interactions with the extragalactic infrared radiation fields. In turn the pairs produced, whose trajectories are randomized by magnetic fields, will inverse…

Astrophysics · Physics 2011-04-11 S. Casanova , B. L. Dingus , Bing Zhang

I review recent observational and theoretical progress in our understanding of the cosmic evolution of luminous sources. Largely due to a combination of deep HST imaging, Keck spectroscopy, and COBE far-IR background measurements, new…

Astrophysics · Physics 2009-10-31 Piero Madau

Measuring the diffuse Galactic gamma-ray flux in the TeV range is difficult for ground-based gamma-ray telescopes because of the residual cosmic-ray background, which is higher than the gamma-ray flux by several orders of magnitude. Its…

High Energy Astrophysical Phenomena · Physics 2020-01-22 A. Neronov , D. V. Semikoz

Our goal is to research the upper limits on the extragalactic background light (EBL). The upper limits on the extragalactic background light (EBL), using the Fermi and very high energy (VHE) spectra recently observed in TeV blazars, are…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Jianping Yang , Jiancheng Wang

The detection of TeV gamma-rays from the blazar H 1426+428 at an integral flux level of (4 +- 2(stat) +- 1(syst)) 10^(-12) erg cm^(-2) s^(-1) above 1 TeV with the HEGRA imaging atmospheric Cherenkov telescope system is reported. H 1426+428…

Astrophysics · Physics 2007-05-23 HEGRA Collaboration , F. Aharonian

In this paper, I will take a synoptic approach to determining the intergalactic infrared radiation field (IIRF). This approach draws on both the multi-TeV gamma-ray observations and the infrared background observations and relates them via…

Astrophysics · Physics 2007-05-23 F. W. Stecker

The discovery of distant sources of very high energy (VHE) gamma-rays with hard energy spectra enabled to derive strong upper limits on the density of the extragalactic background light (EBL). These limits are close to the lower limits…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 M. Raue

The current and forthcoming observations of large samples of high-redshift galaxies selected according to various photometric and spectroscopic criteria can be interpreted in the context of galaxy formation, by means of models of evolving…

Astrophysics · Physics 2007-05-23 B. Guiderdoni , J. E. G. Devriendt

We investigate the nature of the diffuse intra-cluster ultraviolet light seen in twelve local starburst galaxies, using long-slit ultraviolet spectroscopy obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space…

The propagation of very high energy gamma-rays ($E>100$~GeV) over cosmological distances is suppressed by pair-production processes with the ubiquitous extra-galactic soft photon background, mainly in the optical to near infra-red. The…

High Energy Astrophysical Phenomena · Physics 2016-02-25 D. Horns

Current limits on the intensity of the extragalactic infrared background are consistent with the expected contribution from evolving galaxies. Depending on the behaviour of the star formation rate and of the initial mass function, we can…

Astrophysics · Physics 2009-10-22 G. De Zotti , A. Franceschini , P. Mazzei , L. Toffolatti , L. Danese

The far-ultraviolet is the most rapidly evolving portion of the spectrum in both very young galaxies and very old galaxies. The ``UV upturn'' in the spectra of elliptical galaxies shortward of 2000 Angstroms offers a promising probe of the…

Astrophysics · Physics 2009-10-30 Henry C. Ferguson , Thomas M. Brown

Very high energy (VHE, energy >~ 100 GeV) {\gamma}-rays undergo pair production with photons of the extragalactic background light (EBL). Thus, the intrinsic {\gamma}-ray flux of cosmological sources is attenuated and the Universe should be…

High Energy Astrophysical Phenomena · Physics 2013-01-11 Manuel Meyer , Dieter Horns , Martin Raue

One of the most prominent features of the $\gamma$-ray sky is the emission from our own Galaxy. The Galactic plane has been observed by Fermi-LAT in GeV and H.E.S.S. in TeV light. Fermi has modeled the Galactic emission as the sum of a…

High Energy Astrophysical Phenomena · Physics 2015-06-09 Ellis Owen , Christoph Deil , Axel Donath , Régis Terrier

We extend our previous model-independent determination of the intergalactic background light (IBL), based purely on galaxy survey data, out to a wavelength of 5 microns. Our approach enables us to constrain the range of photon densities,…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Sean T. Scully , Matthew A. Malkan , Floyd W. Stecker

The survey of the inner Galaxy with H.E.S.S. was remarkably successful in detecting a wide range of new very-high-energy gamma-ray sources. New TeV gamma-ray emitting source classes were established, although several of the sources remain…

Astrophysics of Galaxies · Physics 2015-05-13 S. Funk , J. A. Hinton , G. Hermann , S. Digel

The extragalactic background light (EBL) in the IR to UV bands partly absorbs very high energy (VHE, $E \geq$ 100GeV) $\gamma-$ray photons travelling over cosmological distances via pair production. In this paper, to get stronger…

High Energy Astrophysical Phenomena · Physics 2023-03-01 Longhua Qin , Jiancheng Wang , Quangui Gao , Weiwei Na , Huaizhen Li , Ao Wang , Chuyuan Yang , Jianping Yang

Using the recent models of Malkan & Stecker (2001) for the infrared background radiation and extrapolating them into the optical and UV range using recent galaxy count data, we rederive the optical depth of the Universe to high energy…

Astrophysics · Physics 2009-11-06 O. C. De Jager , F. W. Stecker
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