Observations of Low and Intermediate Spectral Peak Blazars with the Imaging X-Ray Polarimetry Explorer
Herman L. Marshall, Ioannis Liodakis, Alan P. Marscher, Niccolò Di Lalla, Svetlana G. Jorstad, Dawoon E. Kim, R. Middei, Michela Negro, N. Omodei, Abel L. Peirson, M. Perri, Simonetta Puccetti, M. Laurenti, I. Agudo, G. Bonnoli, A. Berdyugin, E. Cavazzuti, Nicole Rodriguez Cavero, I. Donnarumma, Laura Di Gesu, Jenni Jormanainen, H. Krawczynski, E. Lindfors, Greg Madjeski, Frédéric Marin, F. Massaro, L. Pacciani, Juri Poutanen, F. Tavecchio, Pouya M. Kouch, F. J. Aceituno, M. Bernardos, V. Casanova, Maya Garcı́a-Comas, Beatriz Agı́s-González, C. Husillos, Alessandro Marchini, A. Sota, D. Blinov, Ioakeim G. Bourbah, Sebastian Kielhmann, Evangelos Kontopodis, Nikos Mandarakas, Stylianos Romanopoulos, Raphael Skalidis, Anna Vervelaki, Г. А. Борман, E. N. Kopatskaya, Е. Г. Ларионова, D. A. Morozova, С. С. Савченко, A. A. Vasilyev, А. В. Жовтан, C. Casadio, Juan Escudero, Joana A. Kramer, I. Myserlis, Efthalia Trainou, Ryo Imazawa, Mahito Sasada, Y. Fukazawa, Koji S. Kawabata, Makoto Uemura, Tsunefumi Mizuno, Tatsuya Nakaoka, Hiroshi Akitaya, J. Masiero, Dimitri Mawet, G. V. Panopoulou, Samaporn Tinyanont, Masato Kagitani, Vadim Kravtsov, Takeshi Sakanoi, Matthew Dattolo, Mark Gurwell, Garrett K. Keating, Ramprasad Rao, Whee Yeon Cheong, Hyeon‐Woo Jeong, Sincheol Kang, Sang-Hyun Kim, Sang-Sung Lee, E. Angelakis, Alexander Kraus, Antonio Hales, Seiji Kameno, R. Kneißl, Hugo Messias, Hiroshi Nagai, L. A. Antonelli, Matteo Bachetti, L. Baldini, W. H. Baumgartner, R. Bellazzini, S. Bianchi, Stephen D. Bongiorno, R. Bonino, A. Brez, N. Bucciantini, Fiamma Capitanio
Abstract
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 3 σ 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.