4.7 Article

Variability and Spectral Characteristics of Three Flaring Gamma-Ray Quasars Observed by VERITAS and Fermi-LAT

Journal

ASTROPHYSICAL JOURNAL
Volume 924, Issue 2, Pages -

Publisher

IOP Publishing Ltd
DOI: 10.3847/1538-4357/ac32bd

Keywords

-

Funding

  1. US Department of Energy Office of Science
  2. US National Science Foundation
  3. Smithsonian Institution
  4. NSERC in Canada
  5. Helmholtz Association in Germany
  6. National Science Foundation
  7. US Department of Energy's Office of Science
  8. National Energy Research Scientific Computing Center (NERSC), a US Department of Energy Office of Science User Facility [DE-AC02-05CH11231]
  9. National Aeronautics and Space Administration in the United States
  10. Department of Energy in the United States
  11. Commissariat a l'Energie Atomique in France
  12. Centre National de la Recherche Scientifique/Institut National de Physique Nucleaire et de Physique des Particules in France
  13. Agenzia Spaziale Italiana in Italy
  14. Istituto Nazionale di Fisica Nucleare in Italy
  15. Ministry of Education, Culture, Sports, Science and Technology (MEXT) in Japan
  16. High Energy Accelerator Research Organization (KEK) in Japan
  17. Japan Aerospace Exploration Agency (JAXA) in Japan
  18. K. A. Wallenberg Foundation in Sweden
  19. Swedish Research Council in Sweden
  20. Swedish National Space Board in Sweden
  21. Istituto Nazionale di Astrofisica in Italy
  22. Centre National d'Etudes Spatiales in France
  23. DOE [DE-AC02-76SF00515, DE-SC0016542]
  24. Fermi Guest Investigator grants [NNX08AW56G, NNX09AU10G, NNX12AO93G, NNX15AU81G]
  25. Sloan Fellowship
  26. Cottrell Scholars Award
  27. NASA [80NSSC18K1104, 80GSFC21M0002]
  28. NSF [PHY-1903412, PHY-1707432, PHY-2011420]
  29. National Science Foundation [PHY-1659528]
  30. Columbia University, NY, USA
  31. European Research Council [949555]
  32. NSF at Barnard College, Columbia University [PHY-1806554]
  33. Ecole Polytechnique
  34. Paris 1 Pantheon-Sorbonne University
  35. Science Po
  36. European Research Council (ERC) [949555] Funding Source: European Research Council (ERC)

Ask authors/readers for more resources

This study explores the gamma-ray variability and spectral characteristics of three FSRQs observed at GeV and TeV energies by Fermi-LAT and VERITAS, and explains the GeV flux distributions of the sources using a model based on a stochastic differential equation. The study also analyzes the daily and subdaily variability and gamma-ray energy spectra of the distinct flares identified. Furthermore, the study models the broadband spectral energy distributions of two FSRQs during high-energy flares, providing constraints on the jet Doppler factors and gamma-ray emission region locations. The study also discusses the theoretical constraints on the production of PeV-scale neutrinos during these flares.
Flat-spectrum radio quasars (FSRQs) are the most luminous blazars at GeV energies but only rarely emit detectable fluxes of TeV gamma rays, typically during bright GeV flares. We explore the gamma-ray variability and spectral characteristics of three FSRQs that have been observed at GeV and TeV energies by Fermi-LAT and VERITAS, making use of almost 100 hr of VERITAS observations spread over 10 yr: 3C 279, PKS 1222+216, and Ton 599. We explain the GeV flux distributions of the sources in terms of a model derived from a stochastic differential equation describing fluctuations in the magnetic field in the accretion disk and estimate the timescales of magnetic flux accumulation and stochastic instabilities in their accretion disks. We identify distinct flares using a procedure based on Bayesian blocks and analyze their daily and subdaily variability and gamma-ray energy spectra. Using observations from VERITAS, as well as Fermi, Swift, and the Steward Observatory, we model the broadband spectral energy distributions of PKS 1222+216 and Ton 599 during very high energy (VHE)-detected flares in 2014 and 2017, respectively, strongly constraining the jet Doppler factors and gamma-ray emission region locations during these events. Finally, we place theoretical constraints on the potential production of PeV-scale neutrinos during these VHE flares.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available