eprintid: 10196344 rev_number: 8 eprint_status: archive userid: 699 dir: disk0/10/19/63/44 datestamp: 2024-08-28 14:43:25 lastmod: 2024-12-19 07:10:08 status_changed: 2024-08-28 14:43:25 type: article metadata_visibility: show sword_depositor: 699 creators_name: Heyl, J creators_name: Doroshenko, V creators_name: González-Caniulef, D creators_name: Caiazzo, I creators_name: Poutanen, J creators_name: Mushtukov, A creators_name: Tsygankov, SS creators_name: Kirmizibayrak, D creators_name: Bachetti, M creators_name: Pavlov, GG creators_name: Forsblom, SV creators_name: Malacaria, C creators_name: Suleimanov, VF creators_name: Agudo, I creators_name: Antonelli, LA creators_name: Baldini, L creators_name: Baumgartner, WH creators_name: Bellazzini, R creators_name: Bianchi, S creators_name: Bongiorno, SD creators_name: Bonino, R creators_name: Brez, A creators_name: Bucciantini, N creators_name: Capitanio, F creators_name: Castellano, S creators_name: Cavazzuti, E creators_name: Chen, CT creators_name: Ciprini, S creators_name: Costa, E creators_name: De Rosa, A creators_name: Del Monte, E creators_name: Di Gesu, L creators_name: Di Lalla, N creators_name: Di Marco, A creators_name: Donnarumma, I creators_name: Dovčiak, M creators_name: Ehlert, SR creators_name: Enoto, T creators_name: Evangelista, Y creators_name: Fabiani, S creators_name: Ferrazzoli, R creators_name: Garcia, JA creators_name: Gunji, S creators_name: Hayashida, K creators_name: Iwakiri, W creators_name: Jorstad, SG creators_name: Kaaret, P creators_name: Karas, V creators_name: Kislat, F creators_name: Kitaguchi, T creators_name: Kolodziejczak, JJ creators_name: Krawczynski, H creators_name: La Monaca, F creators_name: Latronico, L creators_name: Liodakis, I creators_name: Maldera, S creators_name: Manfreda, A creators_name: Marin, F creators_name: Marinucci, A creators_name: Marscher, AP creators_name: Marshall, HL creators_name: Massaro, F creators_name: Matt, G creators_name: Mitsuishi, I creators_name: Mizuno, T creators_name: Muleri, F creators_name: Negro, M creators_name: Ng, CY creators_name: O’Dell, SL creators_name: Omodei, N creators_name: Oppedisano, C creators_name: Papitto, A creators_name: Peirson, AL creators_name: Perri, M creators_name: Pesce-Rollins, M creators_name: Petrucci, PO creators_name: Pilia, M creators_name: Possenti, A creators_name: Puccetti, S creators_name: Ramsey, BD creators_name: Rankin, J creators_name: Ratheesh, A creators_name: Roberts, OJ creators_name: Romani, RW creators_name: Sgrò, C creators_name: Slane, P creators_name: Soffitta, P creators_name: Spandre, G creators_name: Swartz, DA creators_name: Tamagawa, T creators_name: Tavecchio, F creators_name: Taverna, R creators_name: Tawara, Y creators_name: Tennant, AF creators_name: Thomas, NE creators_name: Tombesi, F creators_name: Trois, A creators_name: Turolla, R creators_name: Vink, J creators_name: Weisskopf, MC title: Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F63 note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions. abstract: In an accreting X-ray pulsar, a neutron star accretes matter from a companion star through an accretion disk. The magnetic field of the rotating neutron star disrupts the inner edge of the disk, funnelling the gas to flow onto the poles on its surface. Hercules X-1 is a prototypical persistent X-ray pulsar about 7 kpc from Earth. Its emission varies on three distinct timescales: the neutron star rotates every 1.2 s, it is eclipsed by its companion each 1.7 d, and the system exhibits a superorbital period of 35 d, which has remained stable since its discovery. Several lines of evidence point to the source of this variation as the precession of the accretion disk or that of the neutron star. Despite the many hints over the past 50 yr, the precession of the neutron star itself has yet not been confirmed or refuted. X-ray polarization measurements (probing the spin geometry of Her X-1) with the Imaging X-ray Polarimetry Explorer suggest that free precession of the neutron star crust sets the 35 d period; this has the important implication that its crust is somewhat asymmetric by a few parts per ten million. date: 2024-08 date_type: published publisher: NATURE PORTFOLIO official_url: http://dx.doi.org/10.1038/s41550-024-02295-8 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2290990 doi: 10.1038/s41550-024-02295-8 lyricists_name: Wu, Kinwah lyricists_name: Zane, Silvia lyricists_id: KWUXX50 lyricists_id: SZANE58 actors_name: Kalinowski, Damian actors_id: DKALI47 actors_role: owner funding_acknowledgements: [National Aeronautics and Space Administration (NASA)]; NNM15AA18C [Ball Aerospace]; ASI-ASI-OHBI-2022-13-I.0 [Italian Space Agency]; ASI-INAF-2022-19-HH.0 [Italian Space Agency]; ASI-INFN-2017.13-H0 [Italian Space Agency]; ASI-INAF-2022-14-HH.0 [Space Science Data Center]; ASI-INFN 2021-43-HH.0 [Space Science Data Center]; [Italian National Institute for Astrophysics]; [Italian National Institute for Nuclear Physics]; [Natural Sciences and Engineering Research Council of Canada through a discovery grant]; [Canadian Space Agency]; [French National Centre for Space Studies]; 333112 [Academy of Finland]; 349144 [Academy of Finland]; [Vaisala Foundation]; 57525212 [German Academic Exchange Service] full_text_status: public publication: Nature Astronomy volume: 9 pagerange: 1047-1053 pages: 12 citation: Heyl, J; Doroshenko, V; González-Caniulef, D; Caiazzo, I; Poutanen, J; Mushtukov, A; Tsygankov, SS; ... Weisskopf, MC; + view all <#> Heyl, J; Doroshenko, V; González-Caniulef, D; Caiazzo, I; Poutanen, J; Mushtukov, A; Tsygankov, SS; Kirmizibayrak, D; Bachetti, M; Pavlov, GG; Forsblom, SV; Malacaria, C; Suleimanov, VF; Agudo, I; Antonelli, LA; Baldini, L; Baumgartner, WH; Bellazzini, R; Bianchi, S; Bongiorno, SD; Bonino, R; Brez, A; Bucciantini, N; Capitanio, F; Castellano, S; Cavazzuti, E; Chen, CT; Ciprini, S; Costa, E; De Rosa, A; Del Monte, E; Di Gesu, L; Di Lalla, N; Di Marco, A; Donnarumma, I; Dovčiak, M; Ehlert, SR; Enoto, T; Evangelista, Y; Fabiani, S; Ferrazzoli, R; Garcia, JA; Gunji, S; Hayashida, K; Iwakiri, W; Jorstad, SG; Kaaret, P; Karas, V; Kislat, F; Kitaguchi, T; Kolodziejczak, JJ; Krawczynski, H; La Monaca, F; Latronico, L; Liodakis, I; Maldera, S; Manfreda, A; Marin, F; Marinucci, A; Marscher, AP; Marshall, HL; Massaro, F; Matt, G; Mitsuishi, I; Mizuno, T; Muleri, F; Negro, M; Ng, CY; O’Dell, SL; Omodei, N; Oppedisano, C; Papitto, A; Peirson, AL; Perri, M; Pesce-Rollins, M; Petrucci, PO; Pilia, M; Possenti, A; Puccetti, S; Ramsey, BD; Rankin, J; Ratheesh, A; Roberts, OJ; Romani, RW; Sgrò, C; Slane, P; Soffitta, P; Spandre, G; Swartz, DA; Tamagawa, T; Tavecchio, F; Taverna, R; Tawara, Y; Tennant, AF; Thomas, NE; Tombesi, F; Trois, A; Turolla, R; Vink, J; Weisskopf, MC; - view fewer <#> (2024) Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization. Nature Astronomy , 9 pp. 1047-1053. 10.1038/s41550-024-02295-8 <https://doi.org/10.1038/s41550-024-02295-8>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10196344/1/Zane_Complex%20rotational%20dynamics%20of%20the%20neutron%20star%20in%20Hercules%20X-1%20revealed%20by%20X-ray%20polarization_AAM.pdf