2009/12/31 by G. Ghisellini, R. Della Ceca, Marta Volonteri +10 · 2 citations
Physics and Astronomy · #Accretion (finance) #Active galactic nucleus #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Black hole (networking) #Blazar #Extragalactic background light #Fermi Gamma-ray Space Telescope #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma ray #Physics #Radio Astronomy Observations and Technology #Redshift #Sky #Spectral energy distribution #Supermassive black hole #Telescope #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.1111/j.1365-2966.2010.16449.x
Accepted for publication in MNRAS. Absorption due to Lyman-alpha clouds calculated, and optical-UV data de-absorbed. 16 figures, 15 pages
arxiv created 2010/02/01 · openalex publication_date 2010/03/01 · arxiv updated 2015/05/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the physical properties of 10 blazars at redshift greater than 2 detected in the 3-yr all-sky survey performed by the Burst Alert Telescope (BAT) on board the Swift satellite. We find that the jets of these blazars are among the most powerful known. Furthermore, the mass of their central black hole, inferred from the optical–ultraviolet bump, exceeds a few billions of solar masses, with accretion luminosities being a large fraction of the Eddington one. We compare their properties with those of the brightest blazars of the 3-month survey performed by the Large Area Telescope (LAT) on board the Fermi satellite. We find that the BAT blazars have more powerful jets, more luminous accretion discs and larger black hole masses than LAT blazars. These findings can be simply understood on the basis of the blazar sequence, which suggests that the most powerful blazars have a spectral energy distribution with a high-energy peak at MeV (or even sub-MeV) energies. This implies that the most extreme blazars can be found more efficiently in hard X-rays, rather than in the high-energy γ-ray band. We then discuss the implications of our findings for future missions, such as the New Hard X-ray Mission (NHXM) and especially the Energetic X-ray Imaging Survey Telescope (EXIST) mission which, during its planned 2-yr all-sky survey, is expected to detect thousands of blazars, with a few of them at z≳ 6.