Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi -LAT and H.E.S.S. analysis

Aharonian F, Ait Benkhali F, Aschersleben J, Ashkar H, Backes M, Baktash A, Barbosa Martins V, Batzofin R, Becherini Y, Berge D, Bernlöhr K, Bi B, Böttcher M, Boisson C, Bolmont J, De Bony De Lavergne M, Borowska J, Bradascio F, Breuhaus M, Brose R, Brown A, Brun F, Bruno B, Bulik T, Burger-Scheidlin C, Bylund T, Caroff S, Casanova S, Cecil R, Celic J, Cerruti M, Chambery P, Chand T, Chandra S, Chen A, Chibueze J, Chibueze O, Cotter G, Cristofari P, Devin J, Djannati-Ataï A, Djuvsland J, Dmytriiev A, Einecke S, Ernenwein JP, Fegan S, Feijen K, Filipović M, Fontaine G, Füßling M, Funk S, Gabici S, Gallant YA, Giavitto G, Glawion D, Glicenstein JF, Glombitza J, Goswami P, Grolleron G, Grondin MH, Haerer L, Hinton JA, Hofmann W, Holch TL, Holler M, Horns D, Jamrozy M, Jankowsky F, Joshi V, Kasai E, Katarzyński K, Khatoon R, Khélifi B, Kluåºniak W, Komin N, Kosack K, Kostunin D, Kundu A, Guedes Lang R, Le Stum S, Leitl F, Lemière A, Lemoine-Goumard M, Lenain JP, Leuschner F, Luashvili A, Mackey J, Malyshev D, Marandon V, Marinos P, Martí-Devesa G, Marx R, Mehta A, Meyer M, Mitchell A, Moderski R, Mohrmann L, Montanari A, Moulin E, Murach T, De Naurois M, Niemiec J, O'Brien P, Ohm S, Olivera-Nieto L, De Ona Wilhelmi E, Ostrowski M, Panny S, Panter M, Parsons RD, Peron G, Prokhorov DA, Pühlhofer G, Punch M, Quirrenbach A, Regeard M, Reichherzer P, Reimer A, Reimer O, Ren H, Renaud M, Reville B, Rieger F, Roellinghoff G, Rudak B, Sahakian V, Salzmann H, Sasaki M, Schüssler F, Schutte HM, Shapopi JN, Specovius A, Spencer S, Stawarz , Steenkamp R, Steinmassl S, Steppa C, Streil K, Sushch I, Suzuki H, Takahashi T, Tanaka T, Terrier R, Tluczykont M, Tsuji N, Unbehaun T, van Eldik C, Vecchi M, Veh J, Venter C, Vink J, Wach T, Wagner SJ, Wierzcholska A, Zacharias M, Zargaryan D, Zdziarski AA, Zech A, Zouari S, Å»ywucka N, Harding A (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Book Volume: 686

Article Number: A308

DOI: 10.1051/0004-6361/202348651

Abstract

The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy γ rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's γ-ray emission between 1 GeV and ∼100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package GAMMAPY, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing γ-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties.

Authors with CRIS profile

Involved external institutions

Max-Planck-Institut für Kernphysik (MPIK) / Max Planck Institute for Nuclear Physics Germany (DE) Université Paris-Sud France (FR) Noordwes-Universiteit / North-West University South Africa (ZA) University of Adelaide Australia (AU) Nicolaus Copernicus Astronomical Centre of the Polish Academy of Sciences Poland (PL) Jagiellonian University / Uniwersytet Jagielloński (UJ) Poland (PL) Université Paris-Saclay France (FR) Dublin Institute for Advanced Studies (DIAS) Ireland (IE) Leopold-Franzens-Universität Innsbruck / University of Innsbruck Austria (AT) Ruprecht-Karls-Universität Heidelberg Germany (DE) Eberhard Karls Universität Tübingen Germany (DE) Konan University / 甲南大学 Japan (JP) University of Amsterdam Netherlands (NL) University of Namibia (UNAM) Namibia (NA) University of Tokyo Japan (JP) Laboratoire Univers et Théories (LUTH) / Laboratory of the Universe and Theories France (FR) Universität Hamburg (UHH) Germany (DE) Universität Potsdam Germany (DE) University of Oxford United Kingdom (GB) Université de Bordeaux France (FR) University of Montpellier / Université Montpellier France (FR) Institute of Research into the Fundamental Laws of the Universe / Institut de recherche sur les lois fondamentales de l'univers (IRFU) France (FR) Sorbonne Université France (FR) Deutsches Elektronen-Synchrotron DESY Germany (DE) University of Savoy Mont Blanc / Université Savoie Mont Blanc France (FR) Institut national de physique nucléaire et de physique des particules (IN2P3) France (FR) Humboldt-Universität zu Berlin Germany (DE) University of Warsaw / Uniwersytet Warszawski Poland (PL) Institute of Nuclear Physics Polish Academy of Sciences / Instytut Fizyki Jądrowej im. Henryka Niewodniczańskiego Polskiej Akademii Nauk Poland (PL) University of the Witwatersrand (WITS) South Africa (ZA) Yerevan Physics Institute (YerPhI) / Երևանի Ֆիզիկայի Ինստիտուտ Armenia (AM) University of Groningen / Rijksuniversiteit Groningen Netherlands (NL) Nicolaus Copernicus University (NCU) / Uniwersytet Mikołaja Kopernika w Toruniu (UMK) Poland (PL) Laboratoire Leprince-Ringuet (LLR) France (FR) University of Western Sydney Australia (AU) University of Leicester United Kingdom (GB) Riken Institute of Physical and Chemical Research / 理化学研究所 Japan (JP) Los Alamos National Laboratory United States (USA) (US)

How to cite

APA:

Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Baktash, A.,... Harding, A. (2024). Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi -LAT and H.E.S.S. analysis. Astronomy & Astrophysics, 686. https://doi.org/10.1051/0004-6361/202348651

MLA:

Aharonian, F., et al. "Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi -LAT and H.E.S.S. analysis." Astronomy & Astrophysics 686 (2024).

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