%T Cygnus X-3 revealed as a Galactic ultraluminous X-ray source by IXPE
%V 8
%A Alexandra Veledina
%A Fabio Muleri
%A Juri Poutanen
%A Jakub Podgorný
%A Michal Dovčiak
%A Fiamma Capitanio
%A Eugene Churazov
%A Alessandra De Rosa
%A Alessandro Di Marco
%A Sofia V Forsblom
%A Philip Kaaret
%A Henric Krawczynski
%A Fabio La Monaca
%A Vladislav Loktev
%A Alexander A Lutovinov
%A Sergey V Molkov
%A Alexander A Mushtukov
%A Ajay Ratheesh
%A Nicole Rodriguez Cavero
%A James F Steiner
%A Rashid A Sunyaev
%A Sergey S Tsygankov
%A Martin C Weisskopf
%A Andrzej A Zdziarski
%A Stefano Bianchi
%A Joe S Bright
%A Nikolaj Bursov
%A Enrico Costa
%A Elise Egron
%A Javier A Garcia
%A David A Green
%A Mark Gurwell
%A Adam Ingram
%A Jari JE Kajava
%A Ruta Kale
%A Alex Kraus
%A Denys Malyshev
%A Frédéric Marin
%A Giorgio Matt
%A Michael McCollough
%A Ilya A Mereminskiy
%A Nikolaj Nizhelsky
%A Giovanni Piano
%A Maura Pilia
%A Carlotta Pittori
%A Ramprasad Rao
%A Simona Righini
%A Paolo Soffitta
%A Anton Shevchenko
%A Jiri Svoboda
%A Francesco Tombesi
%A Sergei A Trushkin
%A Peter Tsybulev
%A Francesco Ursini
%A Kinwah Wu
%A Iván Agudo
%A Lucio A Antonelli
%A Matteo Bachetti
%A Luca Baldini
%A Wayne H Baumgartner
%A Ronaldo Bellazzini
%A Stephen D Bongiorno
%A Raffaella Bonino
%A Alessandro Brez
%A Niccolò Bucciantini
%A Simone Castellano
%A Elisabetta Cavazzuti
%A Chien-Ting Chen
%A Stefano Ciprini
%A Ettore Del Monte
%A Laura Di Gesu
%A Niccolò Di Lalla
%A Immacolata Donnarumma
%A Victor Doroshenko
%A Steven R Ehlert
%A Teruaki Enoto
%A Yuri Evangelista
%A Sergio Fabiani
%A Riccardo Ferrazzoli
%A Shuichi Gunji
%A Kiyoshi Hayashida
%A Jeremy Heyl
%A Wataru Iwakiri
%A Svetlana G Jorstad
%A Vladimir Karas
%A Fabian Kislat
%A Takao Kitaguchi
%A Jeffery J Kolodziejczak
%A Luca Latronico
%A Ioannis Liodakis
%A Simone Maldera
%A Alberto Manfreda
%A Andrea Marinucci
%A Alan P Marscher
%A Herman L Marshall
%A Francesco Massaro
%A Ikuyuki Mitsuishi
%A Tsunefumi Mizuno
%A Michela Negro
%A Chi-Yung Ng
%A Stephen L O’Dell
%A Nicola Omodei
%A Chiara Oppedisano
%A Alessandro Papitto
%A George G Pavlov
%A Abel L Peirson
%A Matteo Perri
%A Melissa Pesce-Rollins
%A Pierre-Olivier Petrucci
%A Andrea Possenti
%A Simonetta Puccetti
%A Brian D Ramsey
%A John Rankin
%A Oliver Roberts
%A Roger W Romani
%A Carmelo Sgrò
%A Patrick Slane
%A Gloria Spandre
%A Doug Swartz
%A Toru Tamagawa
%A Fabrizio Tavecchio
%A Roberto Taverna
%A Yuzuru Tawara
%A Allyn F Tennant
%A Nicholas E Thomas
%A Alessio Trois
%A Roberto Turolla
%A Jacco Vink
%A Fei Xie
%A Silvia Zane
%P 1031-1046
%D 2024
%I Springer Science and Business Media LLC
%J Nature Astronomy
%K Compact astrophysical objects, High-energy astrophysics
%L discovery10196156
%X The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds a critical value known as the Eddington limit. The discovery of ultraluminous X-ray sources has shown that accretion can proceed even when the apparent luminosity considerably exceeds this limit. A high apparent luminosity might be produced due to the geometric beaming of radiation by an outflow. The outflow half-opening angle, which determines the amplification due to beaming, has never been robustly constrained. Using the Imaging X-ray Polarimetry Explorer, we measured the X-ray polarization in the Galactic X-ray binary Cygnus X-3 (Cyg X-3). We found high, >20%, nearly energy-independent linear polarization orthogonal to the direction of the radio ejections. These properties unambiguously indicate the presence of a collimating outflow from the X-ray binary Cyg X-3 and constrain its half-opening angle to ≲15°. Thus, the source can be used as a laboratory for studying the supercritical accretion regime. This finding underscores the importance of X-ray polarimetry in advancing our understanding of accreting sources.
%O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.