PoS(ICRC2021)816 International th 12–23 July 2021 July 12–23 37 SICS CONFERENCE SICS CONFERENCE Berlin | Germany Berlin Berlin | Germany Cosmic Ray Conference Ray Cosmic ICRC 2021 THE ASTROPARTICLE PHY ICRC 2021 THEASTROPARTICLE PHY https://pos.sissa.it/ on behalf of the 0 ONLINE and Razmik Mirzoyan 1 . Joint fits to MAGIC and Fermi-LAT data disfavour 54 . 0 ± 62 . 5 Γ = Marcos López-Moya ∗ 0, [email protected] International Cosmic Ray Conference (ICRC 2021) Presenter ∗ th the existence of a sub-exponential cut-offframework of in the outer this gap energy pulsar model. range.the The measured Our transition power-law emission from results can curvature are be radiation interpreted discussed to as in in inverse Compton the the (IC) northern scattering outer of gap. chargesThese accelerated results The have been IC published component in Acciari is et expected al. to 2020 continue [1]. towards higher energies. We report the detection ofthe pulsed MAGIC emission telescopes. from After thein the Geminga the Crab pulsar very-high-energy and (PSR domain, Vela J0633+1746) and pulsars,spectrum with its Geminga derived by estimated is MAGIC extends age the from of 15 third GeV 340function to pulsar with 75 ky detected GeV spectral and makes index can it be modeled the by a oldest power-law one. The Max-Planck-Institut für Physik Föhringer Ring 6, 80805 München, Germany Universidad Complutense de Madrid, IPARCOS Institute andCiudad EMFTEL Universitaria, Plaza Department Ciencias 1, 28040 Madrid,E-mail: Spain Copyright owned by the author(s) under the terms of the Creative Commons 0 1 © Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). 37 July 12th – 23rd, 2021 Online – Berlin, Germany MAGIC detection of Geminga: an Inverse Compton tail? Giovanni Ceribella, MAGIC Collaboration (a complete list of authors can be found at the end of the proceedings) PoS(ICRC2021)816 GeV is 75 − 15 [1]. The spectrum Giovanni Ceribella 54 . 0 ± 62 . . No significant signal is found 5 f Γ = 2 Since the launch of the Fermi-LAT space telescope the number of known gamma-ray pulsars Similarly to Crab and Vela, Geminga (PSR J0633+1746) is one of the strongest sources in the The MAGIC telescopes are a set of two 17-meter diameter Cherenkov telescopes located on Observations of the Geminga pulsar with MAGIC were carried out using the Sum-Trigger-II MAGIC observations were combined with 11 years of Fermi-LAT data. Geminga ephemeris The Geminga light curve obtained by MAGIC above 15 GeV is shown in1. Fig. Emission merges smoothly with the one measuredpreviously reported by by Fermi-LAT MAGIC and [7]. is in agreement with the upper limits has increased dramatically. With more than 270sources detections, in pulsars are our now galaxy. the largest classGeVs, The of making spectrum GeV them of hard most to Fermi-LAT detectGeminga, pulsars with only ground-based exhibits the a Cherenkov Crab telescopes. sharp [2]case Actually, cutoff apart and of at from Vela Crab, a [3] the few pulsars emissionany have continues evidence been up of firmly to a detected TeV cut-off from energiesTherefore, finding following [4]. ground. more a pulsars power-law In The at function the high origin without energies of is the one of high-energy the emission mainGeV in goals sky. of pulsars But Cherenkov is telescopes. unlike still them,spectrum unclear. Geminga obtained is by Fermi-LAT much already older showedGeV a and [5]. deviation lacks from radio However, an subsequent emission. exponential attempts cutoffand to The above detect MAGIC 10 first [7] Geminga Geminga at were higher unsuccessful.needed energies in with This order VERITAS made to [6] detect it Geminga clear with that Cherenkov telescopes. further technical developments were 2. Observations the Canary Island of Labelow Palma. 100 GeV with In the recent introduction of years aenergy we novel trigger threshold have system, significantly of the improved Sum-Trigger-II, the which their halves telescopes. the performance are Technical discussed details in on [8]. the implementation of the Sum-Trigger-II system between 2017 and 2019.analysis A pipepline total of was 80 h developedcalibration of and to good the quality improve image data cleaning the werethe are collected. analysis performed use in of A of an dedicated dedicated low-energy iterative Monteeffect procedure. events, Carlo of the in The simulations geomagnetic analysis of which field includes gamma-ray at the showers tens to of GeV. properly account forwere the obtained using Fermi-LAT datavisible [9] in and the used Fermi-LAT toexpected light phase-fold phase MAGIC curve signal events. regions were for fitted The the MAGIC to two analysis. peaks symmetric Gaussian functions to3. obtain the Results from the second peak, P2, is detected at a significance level of 6.25 MAGIC detection of Geminga 1. Introduction well-represented by a power-law function with spectral index in MAGIC data in the P1 phase region. The MAGIC spectrum in the energy range PoS(ICRC2021)816 . Also, f Giovanni Ceribella . In this case, the detected ◦ 90 . f 3 . Simulations of the outer gap pulsar model indicate 54 . 0 ± 62 . 5 Γ = Geminga light curve measured by MAGIC above 15 Two GeV. rotation cycles are shown for clarity. GeV, and by Inverse Compton scattering for the higher end of the reported spectrum. To test for the presence of an exponential cut-off in the combined MAGIC and Fermi-LAT We would like to thank the Instituto de Astrofísica de Canarias for the excellent working con- We compared our observational results with simulations of the Geminga pulsar in the framework We have presented the detection of pulsed gamma-ray emission from the Geminga pulsar with 40 the sub-exponential cut-off case is disfavoured at 3.6 spectrum, expected in classical pulsar models, wean performed exponential a cut-off. joint fit A to pure a power-law exponential function cut-off with is rejected at a significance level of 18 ditions at the Observatorio del RoqueGerman de BMBF, los MPG Muchachos in and La HGF;ERDF Palma. the under the The Italian Spanish financial Ministerio INFN de support Ciencia and of ePID2019-104114RB-C32, INAF; Innovación the PID2019-104114RB-C33, (MICINN) the PID2019-105510GB-C31,PID2019-107847RB- (PID2019-104114RB-C31, Swiss National FundC41, SNF; PID2019-107847RB-C42, the PID2019-107847RB-C44, PID2019-107988GB-C22); theDepartment Indian of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Figure 1: The green-shaded regions highlight the phase intervals corresponding to the P1 and P2 peaks. that electrons accelerated in northern outerrays gap detected would in be responsible the for Geminga the pulsar. most energetic gamma Acknowledgements of the outer gap model [10]. Thethe measured observer’s emission line from P2 of by sight MAGIC requires and the angle the between pulsar rotation axis to be nearly the MAGIC telescopes. Data werethe taken energy using threshold the of Sum-Trigger-II system thewith developed telescopes. the for position reducing of The the emission secondmerges detected emission smoothly with peak above the of 15 one the measured GeV pulsar. at coincidespower lower The law energies in measured by with phase Fermi-LAT, spectrum spectral and is index up well to described 75 by GeV a MAGIC detection of Geminga gamma rays would be produced in the∼ northern outer gap via curvature radiation, for photons below 4. Conclusions PoS(ICRC2021)816 (2021) 7 (2015) 128 (2020) L14 814 68 643 Giovanni Ceribella (2016) A138 (2016) A133 (2018) A66 591 Astrop. Journal 585 620 (2015) 61 (2010) 272 800 720 (2016) 1221 4 322 Astronomy & Astrophysics Astronomy & Astrophysic Astronomy & Astrophysics Astrop. Journal (2013) 98 Science Astrop. Journal 766 IEEE Transactions on Nuclear Science (MAGIC Coll.), “Detection of the Geminga pulsar with MAGIC , et al. et al. Astrop. Journal hints at a power-law tail emission beyond 15 GeV,” Astron. Astrophys. doi:10.1051/0004-6361/202039131 [arXiv:2011.10412 [astro-ph.HE]]. doi:10.1109/TNS.2021.3079262 [6] E. Aliu. et al. (VERITAS Coll.), [7] M. L. Ahnen et al. (MAGIC Coll.), [1] V. A. Acciari [3] H. Abdalla et al. (H.E.S.S. Coll.), [4] S. Ansoldi et al. (MAGIC Coll.), [5] A. Abdo (Fermi-LAT Coll.) [8] F. Dazzi [2] E. Aliu, et al. (MAGIC Coll.), [9] M. Kerr, P. S. Ray, S. Johnston, R. M. Shannon & F. Camilo, MAGIC detection of Geminga Bulgarian Ministry of Education and Science,and National the RI Roadmap Academy Project of DO1-400/18.12.2020 Finlandsupported grant by nr. the Spanish 3200450709, is CEX2019-000920-S), Centro the gratefully de Unidad acknowledged. de Excelencia ExcelenciaMDM-2015-0509-18-2) This "Severo "María and work by de Ochoa" the was Maeztu" CERCA (SEV-2016-0588, also (CEX2019-000918-M, program SEV-2017- oftian the Science Generalitat de Foundation Catalunya; by (HrZZ) the13.12.1.3.02; Project Croa- by the IP-2016-06-9782 DFG and Collaborative ResearchNational the Centers Research SFB823/C4 Centre University and grant of UMO-2016/22/M/ST9/00382; SFB876/C3; and the Rijeka byand Polish the Project FAPERJ. Brazilian MCTIC, CNPq References [10] K. Hirotani PoS(ICRC2021)816 , , , , , , , , , , , , , , , , , , , , 2 3 6 3 3 9 5 2 5 9 1 8 1 1 31 22 11 40 12 17 24 25 ETH also at 4 Finnish , U. Bar- 50 9 36 Universität , T. Saito , L. Nava , S. Paiano , L. Jouvin , G. Vanzo 28 , T. Miener 35 24 1 , Ž. Bošnjak , J. Herrera 25 15 49 , B. De Lotto , F. Tavecchio , N. Giglietto 16 15 , , E. Colombo , E. Lindfors 6 2 5 , B. Machado de , T. Yamamoto 3 11 Croatian MAGIC Croatian MAGIC 26 , M. Bernardos , M. V. Fonseca , K. Mannheim , D. Sobczynska 7 22 13 8 14 23 29 37 Università di Pisa and , A. Baquero INFN MAGIC Group: IPARCOS Institute and 8 , P. G. Prada Moroni 17 9 39 15 Giovanni Ceribella Armenian MAGIC Group: , N. Sahakyan , E. Do Souto Espiñeira , T. Nakamori , M. Gaug , G. Bonnoli , D. Miceli , F. Leone 5 19 , R. Takeishi 7 17 22 University of Lodz, Faculty of 28 6 23 29 , J. Otero-Santos now at Department for Physics , L. Heckmann , J. Jormanainen , S. M. Colak 12 , A. Fattorini 31 , I. Šnidarić 8 , A. Babić , A. De Angelis 15 20 , S. Loporchio 42 45 7 3 12 , E. Bernardini , C. Wunderlich , 1 , M. Pihet also at Port d’Informació Científica , M. Manganaro 13 15 25 , J. van Scherpenberg 50 , Japanese MAGIC Group: Department 34 44 2 26 , E. Moretti , T. Oka , D. Lelas 32 6 3 Croatian MAGIC Group: Ruđer Bošković 26 , S. Cikota , S. Gasparyan , A. Hahn , F. Dazzi , D. Baack 37 , M. Takahashi , S. Mićanović , L. Di Venere , J. Sitarek , H. Bökenkamp 6 6 , M. Will , A. Rugliancich 7 19 14 43 Centro Brasileiro de Pesquisas Físicas (CBPF), 5 6 37 3 , 21 15 , L. Bellizzi Università di Siena and INFN Pisa, I-53100 Siena, 17 10 , M. Persic , S. Ubach Max-Planck-Institut für Physik, D-80805 München, 12 9 13 3 , G. Maneva Max-Planck-Institut für Physik, D-80805 München, , Y. Ohtani 15 11 , A. López-Oramas 31 48 , V. Moreno , I. Vovk , I. Jiménez Martínez 9 9 , T. Surić , K. Asano , A. Lamastra 6 , C. Righi 39 5 , O. Blanch 5 , V. Fallah Ramazani , S. Mender 27 32 4 , D. Hadasch 7 , P. Peñil Centro de Investigaciones Energéticas, Medioambientales y 13 , P. Da Vela , T. Schweizer 15 Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, , F. Di Pierro 23 3 7 20 , A. Tutone , M. Garczarczyk 21 , A. Chilingarian 33 1 , W. Bednarek 13 15 , S. Nozaki 1 , J. Rico 6 , V. Vitale , Y. Suda 5 6 , M. Artero 18 21 , M. Mallamaci , A. Biland 4 , Y. Iwamura 3 , J. Kushida now at University of Innsbruck National Institute for Astrophysics (INAF), I-00136 Rome, Italy 34 12 , D. Morcuende , D. Green 3 , V. D’Elia , D. Elsaesser 31 5 3 , M. López-Moya , L. Pavletić 43 , K. Schmidt , S. Menchiari 42 11 , Y. Chai 11 , 18 , S. Truzzi , K. Noda 24 48 , D. Depaoli , 18 15 38 6 , M. Ribó 32 20 , M. Strzys 7 15 , K. Ishio 6 Japanese MAGIC Group: Department of Physics, Konan University, Kobe, Hyogo , H. Kubo , R. J. García López , C. F. Vigorito Japanese MAGIC Group: Institute for Cosmic Ray Research (ICRR), The University 6 , C. Bigongiari Università di Padova and INFN, I-35131 Padova, Italy , M. Doro now at Ruhr-Universität Bochum, Fakultät für Physik und Astronomie, Astronomisches , M. Makariev 27 40 34 6 Technische Universität Dortmund, D-44221 Dortmund, Germany , A. Arbet Engels , A. Moralejo Inst. for Nucl. Research and Nucl. Energy, Bulgarian Academy of Sciences, BG-1784 now at Department of Astronomy, University of California Berkeley, Berkeley CA 94720 14 , J. G. Green 24 , J. Becerra González 3 , L. Tosti 11 33 Finnish MAGIC Group: Finnish Centre for Astronomy with ESO, University of Turku, 45 7 18 , D. Mazin 29 46 11 34 51 , M. Cerruti , 5 , J. M. Paredes 25 , W. Rhode , B. Schleicher , D. Strom , G. D’Amico , R. López-Coto 15 3 INFN MAGIC Group: INFN Sezione di Torino and Università degli Studi di Torino, I-10125 15 , T. Inada 3 13 , K. Nishijima 29 Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology 30 47 15 , 21 25 5 2 INFN MAGIC Group: INFN Sezione di Perugia, I-06123 Perugia, Italy , D. Dorner , V. Verguilov , Y. Fukazawa , Y. Kobayashi 2 Universitat de Barcelona, ICCUB, IEEC-UB, E-08028 Barcelona, Spain 38 , E. Molina 6 5 , C. Delgado Mendez 13 , I. Batković , P. Majumdar 15 9 18 , I. Puljak 44 , L. A. Antonelli , S. Covino 5 , 26 , R. Paoletti , M. Martínez , N. Godinović 5 Departament de Física, and CERES-IEEC, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain , W. Bhattacharyya 41 20 , M. Teshima Croatian MAGIC Group: University of Rijeka, Department of Physics, 51000 Rijeka, Croatia , F. G. Saturni Armenian MAGIC Group: ICRANet-Armenia at NAS RA, 0019 Yerevan, Armenia , M. Hütten , F. Longo , G. Ceribella 15 , 11 , J. Strišković 12 , K. Nilsson 3 2 3 15 23 5 26 14 30 17 23 28 , A. Donini , S. Fukami also at International Center for Relativistic Astrophysics (ICRA), Rome, Italy , S. Ventura 23 Japanese MAGIC Group: Department of Physics, Yamagata University, Yamagata 990-8560, Japan 1 15 41 , J. A. Barrio , D. Kerszberg , C. Maggio , R. Mirzoyan 35 , J. Cortina 1 INFN MAGIC Group: INFN Sezione di Bari and Dipartimento Interateneo di Fisica dell’Università e del Politecnico di 10 , J. Delgado , C. Nigro 9 , T. Terzić 10 13 , P. Gliwny , S. Ansoldi , D. Paneque , C. Priyadarshi , M. Mariotti , R. Carosi 44 1 36 2 22 , D. Hrupec now at Laboratoire d’Annecy de Physique des Particules (LAPP), CNRS-IN2P3, 74941 Annecy Cedex, France 29 34 , Instituto de Astrofísica de Andalucía-CSIC, Glorieta de la Astronomía s/n, 18008, Granada, Spain 22 , A. Stamerra 3 , S. Lombardi 5 , K. Satalecka 11 11 Croatian MAGIC Group: Josip Juraj Strossmayer University of Osijek, Department of Physics, 31000 Osijek, Croatia 46 7 6 11 , J. Besenrieder , 49 16 , C. Fruck 9 30 15 Deutsches Elektronen-Synchrotron (DESY), D-15738 Zeuthen, Germany 26 14 Japanese MAGIC Group: Physics Program, Graduate School of Advanced Science and Engineering, Hiroshima University, 739- also at Dipartimento di Fisica, Università di Trieste, I-34127 Trieste, Italy Instituto de Astrofísica de Canarias and Dpto. de Astrofísica, Universidad de La Laguna, E-38200, La Laguna, Tenerife, Spain A. Spolon S. Sakurai E. Prandini M. Palatiello V. Neustroev J. M. Miranda M. Karjalainen F. Giordano J. Hoang L. Maraschi M. Delfino D. Dominis Prester L. Font L. Linhoff A. Berti G. Busetto J. L. Contreras Oliveira Fraga MAGIC detection of Geminga Full Authors List: MAGIC Collaboration V. A. Acciari res de Almeida Japanese MAGIC Group: Department ofof Physics, Physics, Kyoto Tokai University, 606-8502 University, Hiratsuka, Kyoto, Japan Salt 259-1292 Lake, Kanagawa, Sector-1, Japan Kolkata 700064,Sofia, India Bulgaria MAGIC Group: Astronomy Research Unit,Institute, University 10000 of Zagreb, Oulu, FI-90014 Croatia Oulu,INFN Finland Roma Tor Vergata, I-00133658-8501, Roma, Italy Japan and Technology, University of Bergen, NO-5020, Norway Institut (AIRUB), 44801 Bochum, Germany 47 Würzburg, D-97074 Würzburg, Germany Group: University of Split,Croatia Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture (FESB), 21000 Split, (PIC), E-08193 Bellaterra (Barcelona), Spain Germany 27 8526 Hiroshima, Japan FI-20014 Turku, Finland Tecnológicas, E-28040 Madrid, Spain Torino, Italy Bari, I-70125 Bari, Italy A. Alikhanyan National Science Laboratory, 0036 Yerevan, Armenia (BIST), E-08193 Bellaterra (Barcelona), Spain of Tokyo, Kashiwa, 277-8582 Chiba, Japan P. Temnikov M. Vazquez Acosta and D. Zarić 1 Università di Udine and INFNZürich, Trieste, CH-8093 I-33100 Zürich, Udine, Switzerland Italy Group: University of Zagreb, Faculty ofEMFTEL Electrical Department, Engineering Universidad and Complutense Computing de (FER), Madrid, 10000 E-2804022290-180 Zagreb, URCA, Madrid, Croatia Rio Spain de Janeiro (RJ), Brazil Physics and Applied Informatics, Department of Astrophysics, 90-236 Lodz,Italy Poland Germany INFN Pisa, I-56126 Pisa, Italy PoS(ICRC2021)816 Giovanni Ceribella Japanese MAGIC Group: Institute for 51 6 MAGIC detection of Geminga INAF Trieste and Dept.Cosmic of Ray Physics Research (ICRR), and The Astronomy, University University of of Tokyo, Kashiwa, Bologna, 277-8582 Bologna, Chiba, Japan Italy