The TANAMI Multiwavelength Program [electronic resource] : Dynamic spectral energy distributions of southern blazars
- Washington, D.C. : United States. Dept. of Energy, 2016.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- Article numbers A130 : digital, PDF file
- Additional Creators:
- SLAC National Accelerator Laboratory
United States. Department of Energy
National Aeronautics and Space Administration Announcement
United States. Department of Energy. Office of Scientific and Technical Information
- Simultaneous broadband spectral and temporal studies of blazars are an important tool for investigating active galactic nuclei (AGN) jet physics. Aims. Here, we study the spectral evolution between quiescent and flaring periods of 22 radio-loud AGN through multiepoch, quasi-simultaneous broadband spectra. For many of these sources these are the first broadband studies. We also use a Bayesian block analysis of Fermi/LAT light curves to determine time ranges of constant flux for constructing quasi-simultaneous spectral energy distributions (SEDs). The shapes of the resulting 81 SEDs are described by two logarithmic parabolas and a blackbody spectrum where needed. The peak frequencies and luminosities agree well with the blazar sequence for low states with higher luminosity implying lower peak frequencies. This is not true for sources in high states. The γ-ray photon index in Fermi/LAT correlates with the synchrotron peak frequency in low and intermediate states. No correlation is present in high states. The black hole mass cannot be determined from the SEDs. Surprisingly, the thermal excess often found in FSRQs at optical/UV wavelengths can be described by blackbody emission and not an accretion disk spectrum. The so-called harder-when-brighter trend, typically seen in X-ray spectra of flaring blazars, is visible in the blazar sequence. Furthermore, our results for low and intermediate states, as well as the Compton dominance, are in agreement with previous results. Black hole mass estimates using recently published parameters are in agreement with some of the more direct measurements. For two sources, estimates disagree by more than four orders of magnitude, possibly owing to boosting effects. The shapes of the thermal excess seen predominantly in flat spectrum radio quasars are inconsistent with a direct accretion disk origin.
- Published through SciTech Connect.
Astronomy and Astrophysics 591 ISSN 0004-6361 AM
F. Krauß; J. Wilms; M. Kadler; R. Ojha; R. Schulz; J. Trüstedt; P. G. Edwards; J. Stevens; E. Ros; W. Baumgartner; T. Beuchert; J. Blanchard; S. Buson; B. Carpenter; T. Dauser; S. Falkner; N. Gehrels; C. Gräfe; S. Gulyaev; H. Hase; S. Horiuchi; A. Kreikenbohm; I. Kreykenbohm; M. Langejahn; K. Leiter; et al.
German Research Foundation (DFG)
- Funding Information:
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