Determination of X-ray pulsar geometry with IXPE polarimetry | Instituto de Astrofísica de Andalucía

DOI:

10.1038/s41550-022-01799-5

Publication date:

08/10/2022

Main author:

Doroshenko, Victor

IAA authors:

Agudo, Iván

Authors:

Doroshenko, Victor;Poutanen, Juri;Tsygankov, Sergey S.;Suleimanov, Valery F.;Bachetti, Matteo;Caiazzo, Ilaria;Costa, Enrico;Di Marco, Alessandro;Heyl, Jeremy;La Monaca, Fabio;Muleri, Fabio;Mushtukov, Alexander A.;Pavlov, George G.;Ramsey, Brian D.;Rankin, John;Santangelo, Andrea;Soffitta, Paolo;Staubert, Rüdiger;Weisskopf, Martin C.;Zane, Silvia;Agudo, Iván;Antonelli, Lucio A.;Baldini, Luca;Baumgartner, Wayne H.;Bellazzini, Ronaldo;Bianchi, Stefano;Bongiorno, Stephen D.;Bonino, Raffaella;Brez, Alessandro;Bucciantini, Niccolò;Capitanio, Fiamma;Castellano, Simone;Cavazzuti, Elisabetta;Ciprini, Stefano;De Rosa, Alessandra;Del Monte, Ettore;Di Gesu, Laura;Di Lalla, Niccolò;Donnarumma, Immacolata;Dovčiak, Michal;Ehlert, Steven R.;Enoto, Teruaki;Evangelista, Yuri;Fabiani, Sergio;Ferrazzoli, Riccardo;Garcia, Javier A.;Gunji, Shuichi;Hayashida, Kiyoshi;Iwakiri, Wataru;Jorstad, Svetlana G.;Karas, Vladimir;Kitaguchi, Takao;Kolodziejczak, Jeffery J.;Krawczynski, Henric;Latronico, Luca;Liodakis, Ioannis;Maldera, Simone;Manfreda, Alberto;Marin, Frédéric;Marinucci, Andrea;Marscher, Alan P.;Marshall, Herman L.;Matt, Giorgio;Mitsuishi, Ikuyuki;Mizuno, Tsunefumi;Ng, Chi-Yung;O'Dell, Stephen L.;Omodei, Nicola;Oppedisano, Chiara;Papitto, Alessandro;Peirson, Abel L.;Perri, Matteo;Pesce-Rollins, Melissa;Pilia, Maura;Possenti, Andrea;Puccetti, Simonetta;Ratheesh, Ajay;Romani, Roger W.;Sgrò, Carmelo;Slane, Patrick;Spandre, Gloria;Sunyaev, Rashid A.;Tamagawa, Toru;Tavecchio, Fabrizio;Taverna, Roberto;Tawara, Yuzuru;Tennant, Allyn F.;Thomas, Nicolas E.;Tombesi, Francesco;Trois, Alessio;Turolla, Roberto;Vink, Jacco;Wu, Kinwah;Xie, Fei

Journal:

Nature Astronomy

Publication type:

Article

Pages:

1433-1443

Abstract:

Using observations of X-ray pulsar Hercules X-1 by the Imaging X-ray Polarimetry Explorer we report a highly significant (>17σ) detection of the polarization signal from an accreting neutron star. The observed degree of linear polarization of ~10% is far below theoretical expectations for this object, and stays low throughout the spin cycle of the pulsar. Both the degree and angle of polarization exhibit variability with the pulse phase, allowing us to measure the pulsar spin position angle 57(2) deg and the magnetic obliquity 12(4) deg, which is an essential step towards detailed modelling of the intrinsic emission of X-ray pulsars. Combining our results with the optical polarimetric data, we find that the spin axis of the neutron star and the angular momentum of the binary orbit are misaligned by at least ~20 deg, which is a strong argument in support of the models explaining the stability of the observed superorbital variability with the precession of the neutron star.

Database:

ADS

SCOPUS

URL:

https://ui.adsabs.harvard.edu/#abs/2022NatAs...6.1433D/abstract

ADS Bibcode:

2022NatAs...6.1433D

Keywords:

Astrophysics - High Energy Astrophysical Phenomena