Polarized x-rays from a magnetar
Creators: name: Taverna, Roberto
name: Turolla, Roberto
name: Muleri, Fabio
name: Heyl, Jeremy
name: Zane, Silvia
name: Baldini, Luca
name: Caniulef, Denis González
name: Bachetti, Matteo
name: Rankin, John
name: Caiazzo, Ilaria
name: Di Lalla, Niccolò
name: Doroshenko, Victor
name: Errando, Manel
name: Gau, Ephraim
name: Kırmızıbayrak, Demet
name: Krawczynski, Henric
name: Negro, Michela
name: Ng, Mason
name: Omodei, Nicola
name: Tamagawa, Toru
name: Uchiyama, Keisuke
name: Weisskopf, Martin C.
name: Agudo, Ivan
name: Antonelli, Lucio A.
name: Baumgartner, Wayne H.
name: Bellazzini, Ronaldo
name: Bianchi, Stefano
name: Bongiorno, Stephen D.
name: Bonino, Raffaella
name: Brez, Alessandro
name: Bucciantini, Niccolò
name: Capitanio, Fiamma
name: Castellano, Simone
name: Cavazzuti, Elisabetta
name: Ciprini, Stefano
name: Costa, Enrico
name: De Rosa, Alessandra
name: Del Monte, Ettore
name: Di Gesu, Laura
name: Di Marco, Alessandro
name: Donnarumma, Immacolata
name: Dovčiak, Michal
name: Ehlert, Steven R.
name: Enoto, Teruaki
name: Evangelista, Yuri
name: Fabiani, Sergio
name: Ferrazzoli, Riccardo
name: Garcia, Javier A.
name: Gunji, Shuichi
name: Hayashida, Kiyoshi
name: Iwakiri, Wataru
name: Jorstad, Svetlana G.
name: Karas, Vladimir
name: Kitaguchi, Takao
name: Kolodziejczak, Jeffery J.
name: La Monaca, Fabio
name: Latronico, Luca
name: Liodakis, Ioannis
name: Maldera, Simone
name: Manfreda, Alberto
name: Marin, Frédéric
name: Marinucci, Andrea
name: Marscher, Alan P.
name: Marshall, Herman L.
name: Matt, Giorgio
name: Mitsuishi, Ikuyuki
name: Mizuno, Tsunefumi
name: Ng, Stephen C. -Y.
name: O'Dell, Stephen L.
name: Oppedisano, Chiara
name: Papitto, Alessandro
name: Pavlov, George G.
name: Peirson, Abel L.
name: Perri, Matteo
name: Pesce-Rollins, Melissa
name: Pilia, Maura
name: Possenti, Andrea
name: Poutanen, Juri
name: Puccetti, Simonetta
name: Ramsey, Brian D.
name: Ratheesh, Ajay
name: Romani, Roger W.
name: Sgrò, Carmelo
name: Slane, Patrick
name: Soffitta, Paolo
name: Spandre, Gloria
name: Tavecchio, Fabrizio
name: Tawara, Yuzuru
name: Tennant, Allyn F.
name: Thomas, Nicolas E.
name: Tombesi, Francesco
name: Trois, Alessio
name: Tsygankov, Sergey
name: Vink, Jacco
name: Wu, Kinwah
name: Xie, Fei
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report on the first detection of linearly polarized x-ray emission from an ultra-magnetized neutron star with the Imaging X-ray Polarimetry Explorer (IXPE). The IXPE 35 observations of the anomalous x-ray pulsar 4U 0142+61 reveal a linear polarization degree of $(12\pm 1)\%$ throughout the IXPE 2--8 keV band. We detect a substantial variation of the polarization with energy: the degree is $(14\pm 1)\%$ at 2--4 keV and $(41\pm 7)\%$ at 5.5--8 keV, while it drops below the instrumental sensitivity around 4--5 keV, where the polarization angle swings by $\sim 90^\circ$. The IXPE observations give us completely new information about the properties of the neutron star surface and magnetosphere and lend further support to the presence of the quantum mechanical effect of vacuum birefringence.
description: 32 pages, 9 figures, 3 tables