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Title: The TANAMI Multiwavelength Program: Dynamic spectral energy distributions of southern blazars

Abstract

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 blazarmore » 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.« less

Authors:
 [1];  [2];  [3];  [4];  [5];  [1];  [6];  [6];  [7];  [8];  [1];  [9];  [8];  [10];  [2];  [2];  [8];  [1];  [11];  [12] more »;  [13];  [1];  [2];  [1];  [1];  [14];  [15];  [11];  [16];  [17];  [6];  [12];  [18];  [6];  [11] « less
  1. Univ. of Erlangen-Nurnberg, Bamberg (Germany); Univ. of Wurzburg (Germany). Inst. for Theoretical Physics and Astrophysics
  2. Univ. of Erlangen-Nurnberg, Bamberg (Germany)
  3. Univ. of Wurzburg (Germany). Inst. for Theoretical Physics and Astrophysics
  4. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland Baltimore County (UMBC), Baltimore, MD (United States); The Catholic Univ. of America, Washington, DC (United States)
  5. Univ. of Erlangen-Nurnberg, Bamberg (Germany); Univ. of Wurzburg (Germany). Inst. for Theoretical Physics and Astrophysics; ASTRON, the Netherlands Institute for Radio Astronomy, Dwingeloo (Netherlands)
  6. Commonwealth Scientific and Industrial Research Organisation (CSIRO) Astronomy and Space Science, Epping (Australia)
  7. Max Planck Inst. for Radio Astronomy, Bonn (Germany); Univ. of Valencia (Spain). Dept. of Astronomy and Astrophysics and Astronomic Observatory
  8. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
  9. Univ. of Concepcion, Casilla (Chile). Dept. of Astronomy
  10. The Catholic Univ. of America, Washington, DC (United States)
  11. Auckland Univ. of Technology (New Zealand). Inst. for Radio Astronomy and Space Research
  12. Federal Agency for Cartography and Geodesy, Kotzting (Germany)
  13. Commonwealth Scientific and Industrial Research Organisation (CSIRO) Astronomy and Space Science, Tuggeranong (Australia)
  14. Univ. of Tasmania, Hobart, TAS (Australia). School of Mathematics and Physics
  15. Radboud Univ., Nijmegen (Netherlands). Dept. of Astrophysics/ IMAPP
  16. National Inst. of Astrophysics (INAF-IAPS), Rome (Italy)
  17. Nordic Optical Telescope, Santa Cruz (Spain)
  18. Hartebeesthoek Radio Astronomy, Krugersdorp (South Africa)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE; National Aeronautic and Space Administration (NASA); German Research Foundation (DFG)
OSTI Identifier:
1355706
Grant/Contract Number:
AC02-76SF00515; NNH09ZDA001N; NH10ZDA001N; NNH12ZDA001N; NNH13ZDA001N-FERMI; WI 1860-10/1
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Astronomy and Astrophysics
Additional Journal Information:
Journal Volume: 591; Journal ID: ISSN 0004-6361
Publisher:
EDP Sciences
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; galaxies: active; BL Lacertae objects: general; quasars: general; relativistic processes

Citation Formats

Krauß, F., Wilms, J., Kadler, M., Ojha, R., Schulz, R., Trüstedt, J., Edwards, P. G., Stevens, J., Ros, E., Baumgartner, W., Beuchert, T., Blanchard, J., Buson, S., Carpenter, B., Dauser, T., Falkner, S., Gehrels, N., Gräfe, C., Gulyaev, S., Hase, H., Horiuchi, S., Kreikenbohm, A., Kreykenbohm, I., Langejahn, M., Leiter, K., Lovell, J. E. J., Müller, C., Natusch, T., Nesci, R., Pursimo, T., Phillips, C., Plötz, C., Quick, J., Tzioumis, A. K., and Weston, S. The TANAMI Multiwavelength Program: Dynamic spectral energy distributions of southern blazars. United States: N. p., 2016. Web. doi:10.1051/0004-6361/201628595.
Krauß, F., Wilms, J., Kadler, M., Ojha, R., Schulz, R., Trüstedt, J., Edwards, P. G., Stevens, J., Ros, E., Baumgartner, W., Beuchert, T., Blanchard, J., Buson, S., Carpenter, B., Dauser, T., Falkner, S., Gehrels, N., Gräfe, C., Gulyaev, S., Hase, H., Horiuchi, S., Kreikenbohm, A., Kreykenbohm, I., Langejahn, M., Leiter, K., Lovell, J. E. J., Müller, C., Natusch, T., Nesci, R., Pursimo, T., Phillips, C., Plötz, C., Quick, J., Tzioumis, A. K., & Weston, S. The TANAMI Multiwavelength Program: Dynamic spectral energy distributions of southern blazars. United States. doi:10.1051/0004-6361/201628595.
Krauß, F., Wilms, J., Kadler, M., Ojha, R., Schulz, R., Trüstedt, J., Edwards, P. G., Stevens, J., Ros, E., Baumgartner, W., Beuchert, T., Blanchard, J., Buson, S., Carpenter, B., Dauser, T., Falkner, S., Gehrels, N., Gräfe, C., Gulyaev, S., Hase, H., Horiuchi, S., Kreikenbohm, A., Kreykenbohm, I., Langejahn, M., Leiter, K., Lovell, J. E. J., Müller, C., Natusch, T., Nesci, R., Pursimo, T., Phillips, C., Plötz, C., Quick, J., Tzioumis, A. K., and Weston, S. Tue . "The TANAMI Multiwavelength Program: Dynamic spectral energy distributions of southern blazars". United States. doi:10.1051/0004-6361/201628595. https://www.osti.gov/servlets/purl/1355706.
@article{osti_1355706,
title = {The TANAMI Multiwavelength Program: Dynamic spectral energy distributions of southern blazars},
author = {Krauß, F. and Wilms, J. and Kadler, M. and Ojha, R. and Schulz, R. and Trüstedt, J. and Edwards, P. G. and Stevens, J. and Ros, E. and Baumgartner, W. and Beuchert, T. and Blanchard, J. and Buson, S. and Carpenter, B. and Dauser, T. and Falkner, S. and Gehrels, N. and Gräfe, C. and Gulyaev, S. and Hase, H. and Horiuchi, S. and Kreikenbohm, A. and Kreykenbohm, I. and Langejahn, M. and Leiter, K. and Lovell, J. E. J. and Müller, C. and Natusch, T. and Nesci, R. and Pursimo, T. and Phillips, C. and Plötz, C. and Quick, J. and Tzioumis, A. K. and Weston, S.},
abstractNote = {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.},
doi = {10.1051/0004-6361/201628595},
journal = {Astronomy and Astrophysics},
number = ,
volume = 591,
place = {United States},
year = {Tue Jun 28 00:00:00 EDT 2016},
month = {Tue Jun 28 00:00:00 EDT 2016}
}

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