2009/07/23 by L. Costamante, Costamante, L., F. Aharonian +9
Engineering · Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Gyrotron and Vacuum Electronics Research #Particle Accelerators and Free-Electron Lasers #astro-ph.CO
paper · pdf · doi:10.48550/arxiv.0907.3966
Proceedings of "4th Heidelberg International Symposium on High Energy Gamma-Ray Astronomy 2008" (Gamma 2008), July 7-11, 2008. Slightly refined text with updated references
arxiv created 2009/07/23 · openalex publication_date 2009/07/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recent VHE observations have unveiled a surprising behaviour in two well-known blazars at opposite sides of the blazar sequence. PKS 2155-304 have shown for the first time in an HBL a large Compton dominance, high gamma-ray luminosities and a cubic relation between X-ray and VHE fluxes. 3C 279 is the first FSRQ detected at VHE. The high luminosity required to overcome the significant absorption caused by the BLR emission cannot be easily reconciled with the historical and quasi-simultaneous SED properties. Both cases shed a new light on the structure and ambient fields of blazars. Contrary to previous claims, it is also shown that 3C 279 --as any FSRQ-- cannot in general provide robust constraints on the EBL.