Simultaneous space and phase resolved X-ray polarimetry of the Crab pulsar and nebula

Niccolò Bucciantini , Riccardo Ferrazzoli , Matteo Bachetti , John Rankin , Niccolò Di Lalla , Carmelo Sgrò , Nicola Omodei , Takao Kitaguchi , Tsunefumi Mizuno , Shuichi Gunji , Eri Watanabe , Luca Baldini , Patrick Slane , Martin C. Weisskopf , Roger W. Romani , Andrea Possenti , Herman L. Marshall , Stefano Silvestri , Luigi Pacciani , Michela Negro , Fabio Muleri , Emma de Oña Wilhelmi , Fei Xie , Jeremy Heyl , Melissa Pesce-Rollins , Josephine Wong , Maura Pilia , Iván Agudo , Lucio A. Antonelli , Wayne H. Baumgartner , Ronaldo Bellazzini , Stefano Bianchi , Stephen D. Bongiorno , Raffaella Bonino , Alessandro Brez , Fiamma Capitanio , Simone Castellano , Elisabetta Cavazzuti , Chien-Ting Chen , Stefano Ciprini , Enrico Costa , Alessandra de Rosa , Ettore del Monte , Laura Di Gesu , Alessandro Di Marco , Immacolata Donnarumma , Victor Doroshenko , Michal Dovčiak , Steven R. Ehlert , Teruaki Enoto , Yuri Evangelista , Sergio Fabiani , Javier A. Garcia , Kiyoshi Hayashida , Wataru Iwakiri , Svetlana G. Jorstad , Philip Kaaret , Vladimir Karas , Fabian Kislat , Jeffery J. Kolodziejczak , Henric Krawczynski , Fabio La Monaca , Luca Latronico , Ioannis Liodakis , Simone Maldera , Alberto Manfreda , Frédéric Marin (1) , Andrea Marinucci , Alan P. Marscher , Francesco Massaro , Giorgio Matt , Ikuyuki Mitsuishi , C. -Y. Ng , Stephen L. O'Dell , Chiara Oppedisano , Alessandro Papitto , George G. Pavlov , Abel L. Peirson , Matteo Perri , Pierre-Olivier Petrucci (2) , Juri Poutanen , Simonetta Puccetti , Brian D. Ramsey , Ajay Ratheesh , Oliver J. Roberts , Paolo Soffitta , Gloria Spandre , Doug Swartz , Toru Tamagawa , Fabrizio Tavecchio , Roberto Taverna , Yuzuru Tawara , Allyn F. Tennant , Nicolas E. Thomas , Francesco Tombesi , Alessio Trois , Sergey Tsygankov , Roberto Turolla , Jacco Vink , Kinwah Wu , Silvia Zane

1 ObAS - Observatoire astronomique de Strasbourg
2 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

The Crab pulsar and its nebula are among the most studied astrophysical systems, and constitute one of the most promising environments where high-energy processes and particle acceleration can be investigated. They are the only objects for which significant X-ray polarization was detected in the past. Here we present the Imaging X-ray Polarimetry Explorer (IXPE) observation of the Crab pulsar and nebula. The total pulsar pulsed emission in the [2-8] keV energy range is unpolarized. Significant polarization up to 15% is detected in the core of the main peak. The nebula has a total space integrated polarized degree of 20% and polarization angle of 145°. The polarized maps show a large variation in the local polarization, and regions with a polarized degree up to 45-50%. The polarization pattern suggests a predominantly toroidal magnetic field. Our findings for the pulsar are inconsistent with most inner magnetospheric models, and suggest emission is more likely to come from the wind region. For the nebula, the polarization map suggests a patchy distribution of turbulence, uncorrelated with the intensity, in contrast with simple expectations from numerical models.

Domaines: Planète et Univers [physics]

Niccolò Bucciantini, Riccardo Ferrazzoli, Matteo Bachetti, John Rankin, Niccolò Di Lalla, et al.. Simultaneous space and phase resolved X-ray polarimetry of the Crab pulsar and nebula. Nature Astronomy, 2023, ⟨10.1038/s41550-023-01936-8⟩. ⟨insu-04071097⟩