A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
IXPE observation of the low-synchrotron peaked blazar S4 0954+65 during an optical-X-ray flare
Tekijät: Kouch, P.M.; Liodakis, I.; Fenu, F.; Zhang, H.; Boula, S.; Middei, R.; Di Gesu, L.; Paraschos, G.F.; Agudo, I.; Jorstad, S.G.; Lindfors, E.; Marscher, A.P.; Krawczynski, H.; Negro, M.; Hu, K.; Kim, D.E.; Cavazzuti, E.; Errando, M.; Blinov, D.; Gourni, A.; Kiehlmann, S.; Kourtidis, A.; Mandarakas, N.; Triantafyllou, N.; Vervelaki, A.; Borman, G.A.; Kopatskaya, E.N.; Larionova, E.G.; Morozova, D.A.; Savchenko, S.S.; Vasilyev, A.A.; Troitskiy, I.S.; Grishina, T.S.; Shishkina, E.V.; Zhovtan, A.V.; Aceituno, F.J.; Bonnoli, G.; Casanova, V.; Escudero, J.; Agís-González, B.; Husillos, C.; Otero-Santos, J.; Piirola, V.; Sota, A.; Myserlis, I.; Gurwell, M.; Keating, G.K.; Rao, R.; Angelakis, E.; Kraus, A.; Antonelli, L.A.; Bachetti, M.; Baldini, L.; Baumgartner, W.H.; Bellazzini, R.; Bianchi, S.; Bongiorno, S.D.; Bonino, R.; Brez, A.; Bucciantini, N.; Capitanio, F.; Castellano, S.; Chen, C.T.; Ciprini, S.; Costa, E.; De Rosa, A.; Del Monte, E.; Di Lalla, N.; Di Marco, A.; Donnarumma, I.; Doroshenko, V.; Dovčiak, M.; Ehlert, S.R.; Enoto, T.; Evangelista, Y.; Fabiani, S.; Ferrazzoli, R.; Garcia, J.A.; Gunji, S.; Hayashida, K.; Heyl, J.; Iwakiri, W.; Kaaret, P.; Karas, V.; Kislat, F.; Kitaguchi, T.; Kolodziejczak, J.J.; La Monaca, F.; Latronico, L.; Maldera, S.; Manfreda, A.; Marin, F.; Marinucci, A.; Marshall, H.L.; Massaro, F.; Matt, G.; Mitsuishi, I.; Mizuno, T.; Muleri, F.; Ng, C.Y.; O'Dell, S.L.; Omodei, N.; Oppedisano, C.; Papitto, A.; Pavlov, G.G.; Peirson, A.L.; Perri, M.; Pesce-Rollins, M.; Petrucci, P.O.; Pilia, M.; Possenti, A.; Poutanen, J.; Puccetti, S.; Ramsey, B.D.; Rankin, J.; Ratheesh, A.; Roberts, O.J.; Sgrò, C.; Slane, P.; Soffitta, P.; Spandre, G.; Swartz, D.A.; Tamagawa, T.; Tavecchio, F.; Taverna, R.; Tawara, Y.; Tennant, A.F.; Thomas, N.E.; Tombesi, F.; Trois, A.; Tsygankov, S.S.; Turolla, R.; Romani, R.W.; Vink, J.; Weisskopf, M.C.; Wu, K.; Xie, F.; Zane, S.
Kustantaja: EDP Sciences
Julkaisuvuosi: 2025
Journal: Astronomy and Astrophysics
Tietokannassa oleva lehden nimi: Astronomy and Astrophysics
Artikkelin numero: A99
Vuosikerta: 695
ISSN: 0004-6361
eISSN: 1432-0746
DOI: https://doi.org/10.1051/0004-6361/202453127
Verkko-osoite: https://doi.org/10.1051/0004-6361/202453127
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/492148173
The X-ray polarization observations, made possible with the Imaging X-ray Polarimetry Explorer (IXPE), offer new ways of probing high-energy emission processes in astrophysical jets from blazars. Here, we report the first X-ray polarization observation of the blazar S4 0954+65 in a high optical and X-ray state. During our multi-wavelength (MWL) campaign of the source, we detected an optical flare whose peak coincided with the peak of an X-ray flare. This optical-X-ray flare most likely took place in a feature moving along the parsec-scale jet, imaged at 43 GHz by the Very Long Baseline Array (VLBA). The 43 GHz polarization angle of the moving component underwent a rotation near the time of the flare. In the optical band, prior to the IXPE observation, we measured the polarization angle to be aligned with the jet axis. In contrast, during the optical flare, the optical polarization angle was perpendicular to the jet axis; after the flare, it reverted to being parallel to the jet axis. Due to the smooth behavior of the optical polarization angle during the flare, we favor shocks as the main acceleration mechanism. We also infer that the ambient magnetic field lines in the jet were parallel to the jet position angle. The average degree of optical polarization during the IXPE observation was (14.3 ± 4.1)%. Despite the flare, we only detected an upper limit of 14% (at 3σ level) on the X-ray polarization degree; however, a reasonable assumption on the X-ray polarization angle results in an upper limit of 8.8% (3σ). We modeled the spectral energy distribution (SED) and spectral polarization distribution (SPD) of S4 0954+65 with leptonic (synchrotron self-Compton) and hadronic (proton and pair synchrotron) models. Our combined MWL polarization observations and SED modeling tentatively disfavor the use of hadronic models for the X-ray emission in S4 0954+65.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
Julkaisussa olevat rahoitustiedot:
European Research Council Executive Agency
University of Wisconsin-Milwaukee, UWM
Aalto-Yliopisto
Weizmann Institute for Science
National Research Foundation of Korea, NRF
National Aeronautics and Space Administration, NASA
European Space Agency, ESA
Institut National de Physique Nucléaire et de Physique des Particules, IN2P3
Korea Research Environment Open Network, KREONET
Junta de Andalucía
Asteroid Terrestrial-impact Last Alert System
Centro Astronómico Hispano en Andalucía
Instituto de Astrofísica de Canarias, IAC
Korea Institute of Science and Technology Information, KISTI
Space Telescope Science Institute, STScI
Smithsonian Institution, SI
California Institute of Technology, CIT
Deutsches ElektronenSynchrotron and Humboldt University
Trinity College Dublin, TCD
Consejo Superior de Investigaciones Científicas, CSIC
VLBA-BU
Academia Sinica, AS
Bulgarian National Science Fund, BNSF
Lawrence Livermore National Laboratory, LLNL
University of Maryland, UMD
IPAC
Max-Planck-Institut für Radioastronomie
BAE Systems
Queen's University Belfast, QUB
Liverpool John Moores University, LJMU
Kanata Telescope
Marshall Space Flight Center, MSFC
Japan Science and Technology Agency, JST
Boston University, BU
European Research Council, ERC
Istituto Nazionale di Astrofisica, INAF
University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University
Horizon 2020
Ministry of Education, Culture, Sports, Science and Technology, MEXT
Korea Astronomy and Space Science Institute, KASI
Horizon ERC, 101040021
Oak Ridge Associated Universities, ORAU, 80GSFC21M0002
Oak Ridge Associated Universities, ORAU
Fermi Guest Investigator Program, AST-2034437
Science and Technology Facilities Council, STFC, ST/T00147X/1
Science and Technology Facilities Council, STFC
Ministry of Education and Science, MES, KP-06-H38/4 (2019, KP-06-PN-68/1 (2022
Ministry of Education and Science, MES
Instituto de Astrofísica de Andalucía, IAA, PID2022-139117NB-C44, PID2019-107847RB-C44, CEX2021-001131-S
Instituto de Astrofísica de Andalucía, IAA
Ministerio de Ciencia e Innovación, MCIN, MCIN/AEI/10.13039/501100011033
Ministerio de Ciencia e Innovación, MCIN
Japan Society for the Promotion of Science, JSPS, JP21H01137
Japan Society for the Promotion of Science, JSPS
National Science Foundation, NSF, AST-2109127, AST-2108622
National Science Foundation, NSF
Agenzia Spaziale Italiana, ASI, ASI-OHBI-2022-13-I.0, ASI-INAF-2022-19-HH.0, ASI-INFN-2017.13-H0
Agenzia Spaziale Italiana, ASI
Horizon 2020 Framework Programme, H2020, 101004719
Horizon 2020 Framework Programme, H2020
European Commission, EC, 1990, ERC-2022-STG – BOOTES – 101076343
European Commission, EC
Fermi GI program cycle 16, 22-FERMI22-0015, 101018682
Space Science Data Center, ASI-INFN 2021-43-HH.0, ASI-INAF-2022-14-HH.0
MIST, 2020R1A2C2009003
University Fellowship Creation Project for Creating Scientific and Technological Innovation, JPMJFS2129
University Fellowship Creation Project for Creating Scientific and Technological Innovation
Fermi Guest Investigator, NNX09AU10G, NNX08AW56G, NNX15AU81G, NNX12AO93G
Instituto Nazionale di Fisica Nucleare, INFN, I/004/11/4
Instituto Nazionale di Fisica Nucleare, INFN
NASA Fermi Guest Investigator, 80NSSC23K1145, 80NSSC23K1507, 80NSSC23K1508
Research Council of Finland, AKA, 317636, 320045
Research Council of Finland, AKA
Heising-Simons Foundation, HSF, 80NSSC18K0284, 12540303, 80NSSC18K1575, J1944/80NSSC19K0112, ST/000198/1, ST/S006109/1, NN12AR55G, HST GO-15889
Hesing-Simons Foundation, HSF
