Observations of Low and Intermediate Spectral Peak Blazars with the Imaging X-Ray Polarimetry Explorer
Authors: Marshall Herman L. , Liodakis Ioannis , Marscher Alan P. , Di Lalla Niccolò , Jorstad Svetlana G. , Kim Dawoon E. , Middei Riccardo , Negro Michela , Omodei Nicola , Peirson Abel L. , Perri Matteo , Puccetti Simonetta , Laurenti Marco , Agudo Iván , Bonnoli Giacomo , Berdyugin Andrei V. , Cavazzuti Elisabetta , Rodriguez Cavero Nicole , Donnarumma Immacolata , Di Gesu Laura , Jormanainen Jenni , Krawczynski Henric , Lindfors Elina , Madjeski Greg , Marin Frédéric , Massaro Francesco , Pacciani Luigi , Poutanen Juri , Tavecchio Fabrizio , Kouch Pouya M. , Aceituno Francisco José , Bernardos Maria I. , Casanova Víctor , García-Comas Maya , Agís-González Beatriz , Husillos César , Marchini Alessandro , Sota Alfredo , Blinov Dmitry , Bourbah Ioakeim G. , Kielhmann Sebastian , Kontopodis Evangelos , Mandarakas Nikos , Romanopoulos Stylianos , Skalidis Raphael , Vervelaki Anna , Borman George A. , Kopatskaya Evgenia N. , Larionova Elena G. , Morozova Daria A. , Savchenko Sergey S. , Vasilyev Andrey A. , Zhovtan Alexey V. , Casadio Carolina , Escudero Juan , Kramer Joana , Myserlis Ioannis , Trainou Efthalia , Imazawa Ryo , Sasada Mahito , Fukazawa Yasushi , Kawabata Koji S. , Uemura Makoto , Mizuno Tsunefumi , Nakaoka Tatsuya , Akitaya Hiroshi , Masiero Joseph R. , Mawet Dimitri , Panopoulou Georgia V. , Tinyanont Samaporn , Kagitani Masato , Kravtsov Vadim , Sakanoi Takeshi , Dattolo Matthew , Gurwell Mark , Keating Garrett , Rao Ramprasad , Cheong Whee Yeon , Jeong Hyeon-Woo , Kang Sincheol , Kim Sang-Hyun , Lee Sang-Sung , Angelakis Emmanouil , Kraus Alexander , Hales Antonio , Kameno Seiji , Kneissl Ruediger , Messias Hugo , Nagai Hiroshi , Antonelli Lucio A. , Bachetti Matteo , Baldini Luca , Baumgartner Wayne H. , Bellazzini Ronaldo , Bianchi Stefano , Bongiorno Stephen D. , Bonino Raffaella , Brez Alessandro , Bucciantini Niccolò , Capitanio Fiamma , Castellano Simone , Chen Chen-Ting , Ciprini Stefano , Costa Enrico , De Rosa Alessandra , Del Monte Ettore , Di Marco Alessandro , Doroshenko Victor , Dovčiak Michal , Ehlert Steven R. , Enoto Teruaki , Evangelista Yuri , Fabiani Sergio , Ferrazzoli Riccardo , Garcia Javier A. , Gunji Shuichi , Hayashida Kiyoshi , Heyl Jeremy , Iwakiri Wataru , Kaaret Philip , Karas Vladimir , Kislat Fabian , Kitaguchi Takao , Kolodziejczak Jeffery J. , La Monaca Fabio , Latronico Luca , Maldera Simone , Manfreda Alberto , Marinucci Andrea , Matt Giorgio , Mitsuishi Ikuyuki , Muleri Fabio , Ng C.-Y. , O’Dell Stephen L. , Oppedisano Chiara , Papitto Alessandro , Pavlov George G. , Pesce-Rollins Melissa , Petrucci Pierre-Olivier , Pilia Maura , Possenti Andrea , Ramsey Brian D. , Rankin John , Ratheesh Ajay , Roberts Oliver J. , Romani Roger W. , Sgrò Carmelo , Slane Patrick , Soffitta Paolo , Spandre Gloria , Swartz Douglas A. , Tamagawa Toru , Taverna Roberto , Tawara Yuzuru , Tennant Allyn F. , Thomas Nicholas E. , Tombesi Francesco , Trois Alessio , Tsygankov Sergey S. , Turolla Roberto , Vink Jacco , Weisskopf Martin C. , Wu Kinwah , Xie Fei , Zane Silvia 
Published: August 2024

Abstract
We present X-ray polarimetry observations from the Imaging X-ray Polarimetry Explorer (IXPE) of three low spectral peak and one intermediate spectral peak blazars, namely 3C 273, 3C 279, 3C 454.3, and S5 0716+714. For none of these objects was IXPE able to detect X-ray polarization at the 3σ level. However, we placed upper limits on the polarization degree at ∼10%–30%. The undetected polarizations favor models where the X-ray band is dominated by unpolarized photons upscattered by relativistic electrons in the jets of blazars, although hadronic models are not completely eliminated. We discuss the X-ray polarization upper limits in the context of our contemporaneous multiwavelength polarization campaigns.