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arXiv · 2407.12779

Analysis of Crab X-ray Polarization using Deeper IXPE Observations

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

Abstract

We present Crab X-ray polarization measurements using IXPE data with a total exposure of 300ks, three times more than the initial 2022 discovery paper. Polarization is detected in three times more pulsar phase bins, revealing an S-shaped $+40^\circ$ polarization angle sweep in the main pulse and ${>}1\sigma$ departures from the OPTIMA optical polarization in both pulses, suggesting different radiation mechanisms or sites for the polarized emission at the two wavebands. Our polarization map of the inner nebula reveals a toroidal magnetic field, as seen in prior IXPE analyses. Along the southern jet, the magnetic field orientation relative to the jet axis changes from perpendicular to parallel and the polarization degree decreases by ${\sim}6\%$. These observations may be explained by kink instabilities along the jet or a collision with a dense, jet-deflecting medium at the tip. Using spectropolarimetric analysis, we find asymmetric polarization in the four quadrants of the inner nebula, as expected for a toroidal field geometry, and a spatial correlation between polarization degree and photon index.

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Josephine Wong, Tsunefumi Mizuno, Niccoló Bucciantini, Roger W. Romani, Yi-Jung Yang, Kuan Liu, Wei Deng, Kazuho Goya, Fei Xie, Maura Pilia, Philip Kaaret, Martin C. Weisskopf, Stefano Silvestri, C. -Y. Ng, Chien-Ting Chen, Iván Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccoló Di Lalla, Alessandro Di Marco, Immacolata Donnarumma, Victor Doroshenko, Michal Dovčiak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Jeremy Heyl, Wataru Iwakiri, Svetlana G. Jorstad, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frédéric Marin, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Giorgio Matt, Ikuyuki Mitsuishi, Fabio Muleri, Michela Negro, Stephen L. O'Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel Lawrence Peirson, Matteo Perri, Melissa Pesce-Rollins, Pierre-Olivier Petrucci, Andrea Possenti, Juri Poutanen, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver J. Roberts, Carmelo Sgró, Patrick Slane, Paolo Soffitta, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey Tsygankov, Roberto Turolla, Jacco Vink, Kinwah Wu. 2024-07-17. Analysis of Crab X-ray Polarization using Deeper IXPE Observations. https://arxiv.org/abs/2407.12779

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