University of Oulu

Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., … Pearson, T. J. (2021). VHE gamma-ray detection of FSRQ QSO B1420+326 and modeling of its enhanced broadband state in 2020. Astronomy & Astrophysics, 647, A163. https://doi.org/10.1051/0004-6361/202039687

VHE gamma-ray detection of FSRQ QSO B1420+326 and modeling of its enhanced broadband state in 2020

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Author: Acciari, V. A.1,2; Ansoldi, S.3,4; Antonelli, L. A.5;
Engels, A. Arbet6; Artero, M.7; Asano, K.8; Baack, D.9; Babic, A.10; Baquero, A.11,12; de Almeida, U. Barres13; Barrio, J. A.11,12; Becerra Gonzalez, J.1,2; Bednarek, W.14; Bellizzi, L.15,16; Bernardini, E.17; Bernardos, M.18,19; Berti, A.20,21; Besenrieder, J.22; Bhattacharyya, W.17; Bigongiari, C.5; Biland, A.6; Blanch, O.7; Bonnoli, G.15,16; Bosnjak, Z.10; Busetto, G.18,19; Carosi, R.23,24; Ceribella, G.22; Cerruti, M.25; Chai, Y.22; Chilingarian, A.26; Cikota, S.10; Colak, S. M.7; Colombo, E.1,2; Contreras, J. L.11,12; Cortina, J.; Covino, S.5; D'Amico, G.22; D'Elia, V.5; Da Vela, P.23,24,27; Dazzi, F.5; De Angelis, A.18,19; De Lotto, B.3,4; Delfino, M.7,28; Delgado, J.7,28; Delgado Mendez, C.; Depaoli, D.20,21; Di Pierro, F.20,21; Di Venere, L.29,30; Do Souto Espineira, E.7; Prester, D. Dominis31; Donini, A.3,4; Dorner, D.32; Doro, M.18,19; Elsaesser, D.9; Ramazani, V. Fallah33; Fattorini, A.9; Ferrara, G.5; Foffano, L.18,19; Fonseca, M. V.11,12; Font, L.34,35; Fruck, C.22; Fukami, S.8; Garcia Lopez, R. J.1,2; Garczarczyk, M.17; Gasparyan, S.36; Gaug, M.34,35; Giglietto, N.29,30; Giordano, F.29,30; Gliwny, P.14; Godinovic, N.37; Green, J. G.5; Green, D.22; Hadasch, D.8; Hahn, A.22; Heckmann, L.22; Herrera, J.1,2; Hoang, J.11,12; Hrupec, D.38; Hutten, M.22; Inada, T.8; Inoue, S.8; Ishio, K.22; Iwamura, Y.8; Jormanainen, J.33; Jouvin, L.7; Kajiwara, Y.39; Karjalainen, M.1,2; Kerszberg, D.7; Kobayashi, Y.8; Kubo, H.39; Kushida, J.40; Lamastra, A.5; Lelas, D.37; Leone, F.5; Lindfors, E.33; Lombardi, S.5; Longo, F.3,4,41; Lopez-Coto, R.18,19; Lopez-Moya, M.11,12; Lopez-Oramas, A.1,2; Loporchio, S.1; Fraga, B. Machado de Oliveira13; Maggio, C.34,35; Majumdar, P.42; Makariev, M.43; Mallamaci, M.18,19; Maneva, G.43; Manganaro, M.31; Mannheim, K.32; Maraschi, L.5; Mariotti, M.18,19; Martinez, M.7; Mazin, D.8,22; Mender, S.9; Micanovic, S.31; Miceli, D.3,4; Miener, T.11,12; Minev, M.7,43,44; Miranda, J. M.15,16; Mirzoyan, R.22; Molina, E.25; Moralejo, A.7; Morcuende, D.11,12; Moreno, V.34,35; Moretti, E.7; Neustroev, V.45; Nigro, C.7; Nilsson, K.33; Ninci, D.7; Nishijima, K.40; Noda, K.8; Nozaki, S.39; Ohtani, Y.8; Oka, T.39; Otero-Santos, J.1,2; Paiano, S.5; Palatiello, M.3,4; Paneque, D.22; Paoletti, R.15,16; Paredes, J. M.25; Pavletic, L.31; Penil, P.11,12; Perennes, C.18,19; Persic, M.3,4,46,47; Moroni, P. G. Prada23,24; Prandini, E.18,19; Priyadarshi, C.7; Puljak, I.37; Rhode, W.9; Ribo, M.25; Rico, J.7; Righi, C.5; Rugliancich, A.23,24; Saha, L.11,12; Sahakyan, N.36; Saito, T.8; Sakurai, S.8; Satalecka, K.17; Saturni, F. G.5; Schleicher, B.32; Schmidt, K.9; Schweizer, T.22; Sitarek, J.14; Snidaric, I.48; Sobczynska, D.14; Spolon, A.18,19; Stamerra, A.5; Strom, D.22; Strzys, M.8; Suda, Y.22; Suric, T.48; Takahashi, M.8; Tavecchio, F.5; Temnikov, P.43; Terzic, T.31; Teshima, M.22,49; Torres-Alba, N.25; Tosti, L.50; Truzzi, S.15,16; Tutone, A.5; van Scherpenberg, J.22; Vanzo, G.1,2; Vazquez Acosta, M.1,2; Ventura, S.15,16; Verguilov, V.43; Vigorito, C. F.20,21; Vitale, V.51; Vovk, I.8; Will, M.22; Zaric, D.37; Angioni, R.52,53; D'Ammando, F.54; Ciprini, S.52,55; Cheung, C. C.56; Orienti, M.54; Pacciani, L.57; Prajapati, P.58; Kumar, P.58; Ganesh, S.58; Minev, M.7,43,44; Kurtenkov, A.59,60; Marchini, A.15; Carrasco, L.61; Escobedo, G.61; Porras, A.61; Recillas, E.61; Lahteenmaki, A.62,63; Tornikoski, M.62; Berton, M.62,64; Tammi, J.62; Vera, R. J. C.62,63; Jorstad, S. G.65,66; Marscher, A. P.65; Weaver, Z. R.65; Hart, M.65; Hallum, M. K.65; Larionov, V. M.66,67; Borman, G. A.68; Grishina, T. S.66; Kopatskaya, E. N.66; Larionova, E. G.66; Nikiforova, A. A.66,67; Morozova, D. A.66; Savchenko, S. S.66; Troitskaya, Yu. V.66; Troitsky, I. S.66; Vasilyev, A. A.66; Hodges, M.69; Hovatta, T.62,64; Kiehlmann, S.70,71; Max-Moerbeck, W.72; Readhead, A. C. S.69; Reeves, R.73; Pearson, T. J.69
Organizations: 1Univ La Laguna, Inst Astrofis Canarias, Tenerife 38200, Spain.
2Univ La Laguna, Dpto Astrofis, Tenerife 38200, Spain.
3Univ Udine, I-33100 Udine, Italy.
4INFN Trieste, I-33100 Udine, Italy.
5Natl Inst Astrophys INAF, I-00136 Rome, Italy.
6Swiss Fed Inst Technol, CH-8093 Zurich, Switzerland.
7Barcelona Inst Sci & Technol BIST, Inst Fis Altes Energies IFAE, Barcelona 08193, Spain.
8Univ Tokyo, Japanese MAGIC Grp, Inst Cosm Ray Res ICRR, Kashiwa, Chiba 2778582, Japan.
9Tech Univ Dortmund, D-44221 Dortmund, Germany.
10Univ Zagreb, Fac Elect Engn & Comp FER, Croatian MAGIC Grp, Zagreb 10000, Croatia.
11Univ Complutense Madrid, IPARCOS Inst, Madrid 28040, Spain.
12Univ Complutense Madrid, EMFTEL Dept, Madrid 28040, Spain.
13URCA, Ctr Brasileiro Pesquisas Fis CBPF, BR-22290180 Rio De Janeiro, RJ, Brazil.
14Univ Lodz, Fac Phys & Appl Informat, Dept Astrophys, PL-90236 Lodz, Poland.
15Univ Siena, I-53100 Siena, Italy.
16INFN Pisa, I-53100 Siena, Italy.
17Deutsch Elektronen Synchrotron DESY, D-15738 Zeuthen, Germany.
18Univ Padua, I-35131 Padua, Italy.
19INFN, I-35131 Padua, Italy.
20INFN MAGIC Grp, INFN Sez Torino, I-10125 Turin, Italy.
21Univ Torino, I-10125 Turin, Italy.
22Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany.
23Univ Pisa, I-56126 Pisa, Italy.
24INFN Pisa, I-56126 Pisa, Italy.
25Univ Barcelona, ICCUB, IEEC UB, Barcelona 08028, Spain.
26Armenian MAGIC Grp, A Alikhanyan Natl Sci Lab, Yerevan, Armenia.
27Univ Innsbruck, Innsbruck, Austria.
28Port Informac Cient PIC, Barcelona 08193, Spain.
29Univ Politecn Bari, INFN MAGIC Grp, INFN Sez Bari, I-70125 Bari, Italy.
30Univ Politecn Bari, Dipartimento Interateneo Fis, I-70125 Bari, Italy.
31Univ Rijeka, Dept Phys, Croatian MAGIC Grp, Rijeka 51000, Croatia.
32Univ Wurzburg, D-97074 Wurzburg, Germany.
33Univ Turku, Finnish Ctr Astron ESO, Finnish MAGIC Grp, Turku 20014, Finland.
34Univ Autonoma Barcelona, Dept Fis, Bellaterra 08193, Spain.
35Univ Autonoma Barcelona, CERES IEEC, Bellaterra 08193, Spain.
36NAS RA, ICRANet Armenia, Armenian MAGIC Grp, Yerevan, Armenia.
37Univ Split, Fac Elect Engn Mech Engn & Naval Architecture FES, Croatian MAGIC Grp, Split 21000, Croatia.
38Josip Juraj Strossmayer Univ Osijek, Dept Phys, Croatian MAGIC Grp, Osijek 31000, Croatia.
39Kyoto Univ, Dept Phys, Japanese MAGIC Grp, Kyoto 6068502, Japan.
40Tokai Univ, Dept Phys, Japanese MAGIC Grp, Hiratsuka, Kanagawa 2591292, Japan.
41Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy.
42HBNI, Saha Inst Nucl Phys, 1-AF Bidhannagar,Sect-1, Kolkata 700064, India.
43Bulgarian Acad Sci, Inst Nucl Res & Nucl Energy, Sofia 1784, Bulgaria.
44Univ Sofia, Dept Astron, Fac Phys, Sofia 1164, Bulgaria.
45Univ Oulu, Astron Res Unit, Finnish MAGIC Grp, Oulu 90014, Finland.
46Univ Bologna, INAF Trieste, Bologna, Italy.
47Univ Bologna, Dept Phys & Astron, Bologna, Italy.
48Rudjer Boskovic Inst, Croatian MAGIC Grp, Zagreb 10000, Croatia.
49Univ Tokyo, Inst Cosm Ray Res ICRR, Japanese MAGIC Grp, Kashiwa, Chiba 2778582, Japan.
50INFN Sez Perugia, INFN MAGIC Grp, I-06123 Perugia, Italy.
51INFN Roma Tor Vergata, INFN MAGIC Grp, I-00133 Rome, Italy.
52ASI Space Sci Data Ctr, Via Politecn Snc, I-00133 Rome, Italy.
53INFN Roma Tor Vergata, Via Ric Sci 1, I-00133 Rome, Italy.
54INAF IRA Bologna, Via P Gobetti 101, I-40129 Bologna, Italy.
55Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy.
56Naval Res Lab, Washington, DC 20375 USA.
57INAF Ist Astrofis & Planetol Spaziali, Via Fosso Cavaliere 100, I-00133 Rome, Italy.
58Phys Res Lab, Ahmadabad, Gujarat, India.
59Bulgarian Acad Sci, Inst Astron, 72 Tsarigradsko Shose Blvd, Sofia 1784, Bulgaria.
60Bulgarian Acad Sci, NAO, 72 Tsarigradsko Shose Blvd, Sofia 1784, Bulgaria.
61Inst Nacl Astrofis Opt & Elect Tonantzintla, Puebla, Mexico.
62Aalto Univ, Metsahovi Radio Observ, Metsahovintie 114, Kylmala 02540, Finland.
63Aalto Univ, Dept Elect & Nanoengn, POB 15500, Aalto 00076, Finland.
64Univ Turku, Finnish Ctr Astron ESO FINCA, Vesilinnantie 5, Turku 20014, Finland.
65Boston Univ, Inst Astrophys Res, 725 Commonwealth Ave, Boston, MA 02215 USA.
66St Petersburg Univ, Astron Inst, Univ Skij Pr 28, St Petersburg 198504, Russia.
67Pulkovo Observ, St Petersburg, Russia.
68Crimean Astrophys Observ, Nauchnyi, Crimea, Ukraine.
69CALTECH, Owens Valley Radio Observ, Pasadena, CA 91125 USA.
70Fdn Res & Technol Hellas, Inst Astrophys, Iraklion 71110, Greece.
71Univ Crete, Dept Phys, Iraklion 70013, Greece.
72Univ Chile, Dept Astron, Camino El Observ 1515, Santiago, Chile.
73Univ Concepcion, Dept Astron, CePIA, Concepcion, Chile.
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.3 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2021090345149
Language: English
Published: EDP Sciences, 2021
Publish Date: 2021-09-03
Description:

Abstract

Context.: QSO B1420+326 is a blazar classified as a flat-spectrum radio quasar (FSRQ). At the beginning of the year 2020, it was found to be in an enhanced flux state and an extensive multiwavelength campaign allowed us to trace the evolution of the flare.

Aims.: We search for very high-energy (VHE) gamma-ray emission from QSO B1420+326 during this flaring state. We aim to characterize and model the broadband emission of the source over different phases of the flare.

Methods: The source was observed with a number of instruments in radio, near-infrared, optical (including polarimetry and spectroscopy), ultraviolet, X-ray, and gamma-ray bands. We use dedicated optical spectroscopy results to estimate the accretion disk and the dust torus luminosity. We performed spectral energy distribution modeling in the framework of combined synchrotron-self-Compton and external Compton scenario in which the electron energy distribution is partially determined from acceleration and cooling processes.

Results: During the enhanced state, the flux of both SED components of QSO B1420+326 drastically increased and the peaks were shifted to higher energies. Follow-up observations with the MAGIC telescopes led to the detection of VHE gamma-ray emission from this source, making it one of only a handful of FSRQs known in this energy range. Modeling allows us to constrain the evolution of the magnetic field and electron energy distribution in the emission region. The gamma-ray flare was accompanied by a rotation of the optical polarization vector during a low -polarization state. Also, a new superluminal radio knot contemporaneously appeared in the radio image of the jet. The optical spectroscopy shows a prominent FeII bump with flux evolving together with the continuum emission and a MgII line with varying equivalent width.

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Series: Astronomy and astrophysics
ISSN: 0004-6361
ISSN-E: 1432-0746
ISSN-L: 0004-6361
Volume: 647
Article number: A163
DOI: 10.1051/0004-6361/202039687
OADOI: https://oadoi.org/10.1051/0004-6361/202039687
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Subjects:
Funding: We would like to dedicate this paper to the memory of our friend and colleague, Dr. Valeri Larionov (1950 2020), who enthusiastically contributed to this and many other projects aimed at understanding blazars. We would like to thank the Instituto de Astrofisica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish MINECO (FPA2017-87859-P, FPA2017-85668-P, FPA2017-82729C6-2-R, FPA2017-82729-C6-6-R, FPA2017-82729-C6-5-R, AYA2015-71042P, AYA2016-76012-C3-1-P, ESP2017-87055-C2-2-P, FPA2017-90566-REDC); the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-268/16.12.2019 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia "Severo Ochoa" SEV-2016-0588 and SEV2015-0548, the Unidad de Excelencia "Maria de Maeztu" MDM-2014-0369 and the "la Caixa" Foundation (fellowship LCF/BQ/PI18/11630012), by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq and FAPERJ. The Fermi-LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT, as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States; the Commissariat a l'Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucleaire et de Physique des Particules in France; the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy; the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK), and Japan Aerospace Exploration Agency (JAXA) in Japan; and the K. A. Wallenberg Foundation, the Swedish Research Council, and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d'Etudes Spatiales in France. This work was performed in part under DOE Contract DE-AC0276SF00515. This publication makes use of data obtained at the Metsahovi Radio Observatory, operated by Aalto University in Finland. This research has made use of data from the OVRO 40m monitoring program Richards et al. and NNX14AQ89G and NSF grants AST-0808050 and AST-1109911. This study was based in part on observations conducted using the 1.8m Perkins Telescope Observatory (PTO) in Arizona, which is owned and operated by Boston University. The research at Boston University was supported in part by NASA Fermi GI program grants 80NSSC17K0649, 80NSSC19K1504, and 80NSSC19K1505. We thank the ASAS-SN team for making their data publicly available. The VLBA is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated by Associated Universities, Inc.; This work made use of the Lowell Discovery Telescope (formerly Discovery Channel Telescope) at Lowell Observatory. Lowell is a private, nonprofit institution dedicated to astrophysical research and public appreciation of astronomy and operates the LDT in partnership with Boston University, the University of Maryland, the University of Toledo, Northern Arizona University, and Yale University. We acknowledge support by Bulgarian National Science Fund under grant DN18-10/2017 and National RI Roadmap Projects DO1-277/16.12.2019 and DO1-268/16.12.2019 of the Ministry of Education and Science of the Republic of Bulgaria.
Copyright information: © ESO 2021.