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

C. B. Adams; J. Batshoun; W. Benbow; A. Brill; J. H. Buckley; M. Capasso; B. Cavins; J. L. Christiansen; P. Coppi; M. Errando; K. A. Farrell; Q. Feng; J. P. Finley; G. M. Foote; L. Fortson; A. Furniss; A. Gent; C. Giuri; D. Hanna; T. Hassan; O. Hervet; J. Holder; M. Houck; T. B. Humensky; W. Jin; P. Kaaret; M. Kertzman; D. Kieda; F. Krennrich; S. Kumar; M. Lundy; G. Maier; C. E. McGrath; P. Moriarty; R. Mukherjee; D. Nieto; M. Nievas-Rosillo; S. O'Brien; R. A. Ong; A. Oppenheimer; A. N. Otte; S. Patel; K. Pfrang; M. Pohl; R. R. Prado; E. Pueschel; J. Quinn; K. Ragan; P. T. Reynolds; A. Rhatigan; D. Ribeiro; E. Roache; J. L. Ryan; M. Santander; G. H. Sembroski; D. A. Williams; T. J. Williamson; J. Valverde; D. Horan; S. Buson; C. C. Cheung; S. Ciprini; D. Gasparrini; R. Ojha; P. Van Zyl; L. Sironi

doi:10.3847/1538-4357/ac32bd

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

C. B. Adams
, J. Batshoun
, W. Benbow
, A. Brill
, J. H. Buckley
, M. Capasso
, B. Cavins
, J. L. Christiansen
, P. Coppi
, M. Errando
, K. A. Farrell
, Q. Feng
, J. P. Finley
, G. M. Foote
, L. Fortson
, A. Furniss
, A. Gent
, C. Giuri
, D. Hanna
, T. Hassan

O. Hervet, J. Holder, M. Houck, T. B. Humensky, W. Jin, P. Kaaret, M. Kertzman, D. Kieda, F. Krennrich, S. Kumar, M. Lundy, G. Maier, C. E. McGrath, P. Moriarty, R. Mukherjee, D. Nieto, M. Nievas-Rosillo, S. O'Brien, R. A. Ong, A. Oppenheimer, A. N. Otte, S. Patel, K. Pfrang, M. Pohl, R. R. Prado, E. Pueschel, J. Quinn, K. Ragan, P. T. Reynolds, A. Rhatigan, D. Ribeiro, E. Roache, J. L. Ryan, M. Santander, G. H. Sembroski, D. A. Williams, T. J. Williamson, J. Valverde, D. Horan, S. Buson, C. C. Cheung, S. Ciprini, D. Gasparrini, R. Ojha, P. Van Zyl, L. Sironi

Barnard College
California State University - East Bay
Center for Astrophysics | Harvard & Smithsonian
Columbia University
NASA Goddard Space Flight Center
Washington University in St. Louis
University of California at Santa Cruz
California Polytechnic State University, San Luis Obispo
Yale University
University College Dublin
Purdue University
The Bartol Research Institute
University of Minnesota
College of Computing
c/o DESY
McGill University
Davidson College
University of California
University of Alabama
University of Iowa
DePauw University
University of Utah
Iowa State University
IDA Business Park
IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos)
University of California, Los Angeles
Hastings High School
University of Chicago
University of Potsdam
Cork Institute of Technology
Biochemical and Environmental Engineering
University of Würzburg
Naval Research Laboratory
INFN Roma Tor Vergata
Asi Science Data Centre
Science and Research Directorate
GSFC Laboratory for Atmopsheres
University of the Witwatersrand, Johannesburg
South African Radio Astronomy Observatory (SARAO)

Research output: Contribution to journal › Article › peer-review

Abstract

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.

Original language	English
Article number	95
Journal	Astrophysical Journal
Volume	924
Issue number	2
DOIs	https://doi.org/10.3847/1538-4357/ac32bd
Publication status	Published - 10 Jan 2022

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Adams, C. B., Batshoun, J., Benbow, W., Brill, A., Buckley, J. H., Capasso, M., Cavins, B., Christiansen, J. L., Coppi, P., Errando, M., Farrell, K. A., Feng, Q., Finley, J. P., Foote, G. M., Fortson, L., Furniss, A., Gent, A., Giuri, C., Hanna, D., ... Sironi, L. (2022). Variability and Spectral Characteristics of Three Flaring Gamma-Ray Quasars Observed by VERITAS and Fermi-LAT. Astrophysical Journal, 924(2), Article 95. https://doi.org/10.3847/1538-4357/ac32bd

@article{105f568f76274e02a221790c62791371,

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

abstract = "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.",

author = "Adams, \{C. B.\} and J. Batshoun and W. Benbow and A. Brill and Buckley, \{J. H.\} and M. Capasso and B. Cavins and Christiansen, \{J. L.\} and P. Coppi and M. Errando and Farrell, \{K. A.\} and Q. Feng and Finley, \{J. P.\} and Foote, \{G. M.\} and L. Fortson and A. Furniss and A. Gent and C. Giuri and D. Hanna and T. Hassan and O. Hervet and J. Holder and M. Houck and Humensky, \{T. B.\} and W. Jin and P. Kaaret and M. Kertzman and D. Kieda and F. Krennrich and S. Kumar and M. Lundy and G. Maier and McGrath, \{C. E.\} and P. Moriarty and R. Mukherjee and D. Nieto and M. Nievas-Rosillo and S. O'Brien and Ong, \{R. A.\} and A. Oppenheimer and Otte, \{A. N.\} and S. Patel and K. Pfrang and M. Pohl and Prado, \{R. R.\} and E. Pueschel and J. Quinn and K. Ragan and Reynolds, \{P. T.\} and A. Rhatigan and D. Ribeiro and E. Roache and Ryan, \{J. L.\} and M. Santander and Sembroski, \{G. H.\} and Williams, \{D. A.\} and Williamson, \{T. J.\} and J. Valverde and D. Horan and S. Buson and Cheung, \{C. C.\} and S. Ciprini and D. Gasparrini and R. Ojha and \{Van Zyl\}, P. and L. Sironi",

note = "Publisher Copyright: {\textcopyright} 2022. The Author(s). Published by the American Astronomical Society.",

year = "2022",

month = jan,

day = "10",

doi = "10.3847/1538-4357/ac32bd",

language = "English",

volume = "924",

journal = "Astrophysical Journal",

issn = "0004-637X",

number = "2",

}

Adams, CB, Batshoun, J, Benbow, W, Brill, A, Buckley, JH, Capasso, M, Cavins, B, Christiansen, JL, Coppi, P, Errando, M, Farrell, KA, Feng, Q, Finley, JP, Foote, GM, Fortson, L, Furniss, A, Gent, A, Giuri, C, Hanna, D, Hassan, T, Hervet, O, Holder, J, Houck, M, Humensky, TB, Jin, W, Kaaret, P, Kertzman, M, Kieda, D, Krennrich, F, Kumar, S, Lundy, M, Maier, G, McGrath, CE, Moriarty, P, Mukherjee, R, Nieto, D, Nievas-Rosillo, M, O'Brien, S, Ong, RA, Oppenheimer, A, Otte, AN, Patel, S, Pfrang, K, Pohl, M, Prado, RR, Pueschel, E, Quinn, J, Ragan, K, Reynolds, PT, Rhatigan, A, Ribeiro, D, Roache, E, Ryan, JL, Santander, M, Sembroski, GH, Williams, DA, Williamson, TJ, Valverde, J, Horan, D, Buson, S, Cheung, CC, Ciprini, S, Gasparrini, D, Ojha, R, Van Zyl, P & Sironi, L 2022, 'Variability and Spectral Characteristics of Three Flaring Gamma-Ray Quasars Observed by VERITAS and Fermi-LAT', Astrophysical Journal, vol. 924, no. 2, 95. https://doi.org/10.3847/1538-4357/ac32bd

TY - JOUR

T1 - Variability and Spectral Characteristics of Three Flaring Gamma-Ray Quasars Observed by VERITAS and Fermi-LAT

AU - Adams, C. B.

AU - Batshoun, J.

AU - Benbow, W.

AU - Brill, A.

AU - Buckley, J. H.

AU - Capasso, M.

AU - Cavins, B.

AU - Christiansen, J. L.

AU - Coppi, P.

AU - Errando, M.

AU - Farrell, K. A.

AU - Feng, Q.

AU - Finley, J. P.

AU - Foote, G. M.

AU - Fortson, L.

AU - Furniss, A.

AU - Gent, A.

AU - Giuri, C.

AU - Hanna, D.

AU - Hassan, T.

AU - Hervet, O.

AU - Holder, J.

AU - Houck, M.

AU - Humensky, T. B.

AU - Jin, W.

AU - Kaaret, P.

AU - Kertzman, M.

AU - Kieda, D.

AU - Krennrich, F.

AU - Kumar, S.

AU - Lundy, M.

AU - Maier, G.

AU - McGrath, C. E.

AU - Moriarty, P.

AU - Mukherjee, R.

AU - Nieto, D.

AU - Nievas-Rosillo, M.

AU - O'Brien, S.

AU - Ong, R. A.

AU - Oppenheimer, A.

AU - Otte, A. N.

AU - Patel, S.

AU - Pfrang, K.

AU - Pohl, M.

AU - Prado, R. R.

AU - Pueschel, E.

AU - Quinn, J.

AU - Ragan, K.

AU - Reynolds, P. T.

AU - Rhatigan, A.

AU - Ribeiro, D.

AU - Roache, E.

AU - Ryan, J. L.

AU - Santander, M.

AU - Sembroski, G. H.

AU - Williams, D. A.

AU - Williamson, T. J.

AU - Valverde, J.

AU - Horan, D.

AU - Buson, S.

AU - Cheung, C. C.

AU - Ciprini, S.

AU - Gasparrini, D.

AU - Ojha, R.

AU - Van Zyl, P.

AU - Sironi, L.

PY - 2022/1/10

Y1 - 2022/1/10

N2 - 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.

AB - 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.

U2 - 10.3847/1538-4357/ac32bd

DO - 10.3847/1538-4357/ac32bd

M3 - Article

AN - SCOPUS:85123892625

SN - 0004-637X

VL - 924

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

M1 - 95

ER -

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

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