eprintid: 10195866 rev_number: 14 eprint_status: archive userid: 699 dir: disk0/10/19/58/66 datestamp: 2024-08-19 12:33:09 lastmod: 2025-01-07 16:20:15 status_changed: 2024-08-19 12:33:09 type: article metadata_visibility: show sword_depositor: 699 creators_name: Wong, J creators_name: Mizuno, T creators_name: Wu, KInwah creators_name: Zane, S creators_name: Turolla, R creators_name: et, al. title: Analysis of Crab X-ray Polarization using Deeper IXPE Observations ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F63 note: © 2024. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence (https://creativecommons.org/licenses/by/4.0/). abstract: We present Crab X-ray polarization measurements using Imaging X-Ray Polarimetry Explorer (IXPE) data with a total exposure of 300 ks, three times more than the initial 2022 discovery paper. Polarization is detected in three times more pulsar phase bins, revealing an S-shaped +40° polarization angle sweep in the main pulse and >1σ 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 ∼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. date: 2024 date_type: published publisher: IOP Publishing official_url: https://doi.org/10.3847/1538-4357/ad6309 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2305479 doi: 10.3847/1538-4357/ad6309 lyricists_name: Zane, Silvia lyricists_id: SZANE58 actors_name: Zane, Silvia actors_id: SZANE58 actors_role: owner full_text_status: public publication: The Astrophysical Journal volume: 973 number: 2 article_number: 172 citation: Wong, J; Mizuno, T; Wu, KInwah; Zane, S; Turolla, R; et, al.; (2024) Analysis of Crab X-ray Polarization using Deeper IXPE Observations. The Astrophysical Journal , 973 (2) , Article 172. 10.3847/1538-4357/ad6309 <https://doi.org/10.3847/1538-4357%2Fad6309>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10195866/7/Zane_Analysis%20of%20Crab%20X-ray%20Polarization%20using%20Deeper%20IXPE%20Observations_VoR.pdf