2006/10/18 by P. Padovani · 4 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Blazar #Cosmology #Galaxy #Gamma ray #Neutrino Physics Research #Physics #Quasar #Radio Astronomy Observations and Technology #Redshift #Sequence (biology) #astro-ph
paper · pdf · doi:10.1007/s10509-007-9455-2
published as Astrophys.SpaceSci.309:63-71,2007 · 9 pages, 4 figures, invited talk at the Workshop "The Multi-messenger approach to high energy gamma-ray sources", Barcelona, Spain, July 4-7, 2006, to appear in the proceedings
arxiv created 2006/10/18 · openalex publication_date 2007/04/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The "blazar sequence" posits that the most powerful BL Lacertae objects and flat-spectrum radio quasars should have relatively small synchrotron peak frequencies, nupeak, and that the least powerful such objects should have the highest nupeak values. This would have strong implications for our understanding of jet formation and physics and the possible detection of powerful, moderately high-redshift TeV blazars. I review the validity of the blazar sequence by using the results of very recent surveys and compare its detailed predictions against observational data. I find that the blazar sequence in its simplest form is ruled out. However, powerful flat-spectrum radio quasars appear not to reach the nupeak typical of BL Lacs. This could indeed be related to some sort of sequence, although it cannot be excluded that it is instead due to a selection effect.