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arXiv · 2211.13764

X-ray Polarization Observations of BL Lacertae

Riccardo Middei·Ioannis Liodakis·Matteo Perri·Simonetta Puccetti·Elisabetta Cavazzuti·Laura Di Gesu·Steven R. Ehlert·Grzegorz Madejski·Alan P. Marscher·Herman L. Marshall·Fabio Muleri·Michela Negro·Svetlana G. Jorstad·Beatriz Agís-González·Iván Agudo·Giacomo Bonnoli·Maria I. Bernardos·Víctor Casanova·Maya García-Comas·César Husillos·Alessandro Marchini·Alfredo Sota·Pouya M. Kouch·George A. Borman·Evgenia N. Kopatskaya·Elena G. Larionova·Daria A. Morozova·Sergey S. Savchenko·Andrey A. Vasilyev·Alexey V. Zhovtan·Carolina Casadio·Juan Escudero·Ioannis Myserlis·Antonio Hales·Seiji Kameno·Ruediger Kneissl·Hugo Messias·Hiroshi Nagai·Dmitry Blinov·Ioakeim G. Bourbah·Sebastian Kiehlmann·Evangelos Kontopodis·Nikos Mandarakas·Stylianos Romanopoulos·Raphael Skalidis·Anna Vervelaki·Joseph R. Masiero·Dimitri Mawet·Maxwell A. Millar-Blanchaer·Georgia V. Panopoulou·Samaporn Tinyanont·Andrei V. Berdyugin·Masato Kagitani·Vadim Kravtsov·Takeshi Sakanoi·Ryo Imazawa·Mahito Sasada·Yasushi Fukazawa·Koji S. Kawabata·Makoto Uemura·Tsunefumi Mizuno·Tatsuya Nakaoka·Hiroshi Akitaya·Mark Gurwell·Ramprasad Rao·Niccoló Di Lalla·Nicoló Cibrario·Immacolata Donnarumma·Dawoon E. Kim·Nicola Omodei·Luigi Pacciani·Juri Poutanen·Fabrizio Tavecchio·Lucio A. Antonelli·Matteo Bachetti·Luca Baldini·Wayne H. Baumgartner·Ronaldo Bellazzini·Stefano Bianchi·Stephen D. Bongiorno·Raffaella Bonino·Alessandro Brez·Niccoló Bucciantini·Fiamma Capitanio·Simone Castellano·Stefano Ciprini·Enrico Costa·Alessandra De Rosa·Ettore Del Monte·Alessandro Di Marco·Victor Doroshenko·Michal Dovčiak·Teruaki Enoto·Yuri Evangelista·Sergio Fabiani·Riccardo Ferrazzoli·Javier A. Garcia·Shuichi Gunji·Kiyoshi Hayashida·Jeremy Heyl
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Abstract

Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus the Synchrotron emission to be responsible for the low frequency peak, while the origin of the high frequency hump is still debated. The analysis of X-rays and their polarization can provide a valuable tool to understand the physical mechanisms responsible for the origin of high-energy emission of blazars. We report the first observations of BL Lacertae performed with the Imaging X-ray Polarimetry Explorer ({IXPE}), from which an upper limit to the polarization degree $Π_X<$12.6\% was found in the 2-8 keV band. We contemporaneously measured the polarization in radio, infrared, and optical wavelengths. Our multiwavelength polarization analysis disfavors a significant contribution of proton synchrotron radiation to the X-ray emission at these epochs. Instead, it supports a leptonic origin for the X-ray emission in BL Lac.

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Riccardo Middei, Ioannis Liodakis, Matteo Perri, Simonetta Puccetti, Elisabetta Cavazzuti, Laura Di Gesu, Steven R. Ehlert, Grzegorz Madejski, Alan P. Marscher, Herman L. Marshall, Fabio Muleri, Michela Negro, Svetlana G. Jorstad, Beatriz Agís-González, Iván Agudo, Giacomo Bonnoli, Maria I. Bernardos, Víctor Casanova, Maya García-Comas, César Husillos, Alessandro Marchini, Alfredo Sota, Pouya M. Kouch, George A. Borman, Evgenia N. Kopatskaya, Elena G. Larionova, Daria A. Morozova, Sergey S. Savchenko, Andrey A. Vasilyev, Alexey V. Zhovtan, Carolina Casadio, Juan Escudero, Ioannis Myserlis, Antonio Hales, Seiji Kameno, Ruediger Kneissl, Hugo Messias, Hiroshi Nagai, Dmitry Blinov, Ioakeim G. Bourbah, Sebastian Kiehlmann, Evangelos Kontopodis, Nikos Mandarakas, Stylianos Romanopoulos, Raphael Skalidis, Anna Vervelaki, Joseph R. Masiero, Dimitri Mawet, Maxwell A. Millar-Blanchaer, Georgia V. Panopoulou, Samaporn Tinyanont, Andrei V. Berdyugin, Masato Kagitani, Vadim Kravtsov, Takeshi Sakanoi, Ryo Imazawa, Mahito Sasada, Yasushi Fukazawa, Koji S. Kawabata, Makoto Uemura, Tsunefumi Mizuno, Tatsuya Nakaoka, Hiroshi Akitaya, Mark Gurwell, Ramprasad Rao, Niccoló Di Lalla, Nicoló Cibrario, Immacolata Donnarumma, Dawoon E. Kim, Nicola Omodei, Luigi Pacciani, Juri Poutanen, Fabrizio Tavecchio, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccoló Bucciantini, Fiamma Capitanio, Simone Castellano, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Alessandro Di Marco, Victor Doroshenko, Michal Dovčiak, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl. 2022-11-24. X-ray Polarization Observations of BL Lacertae. https://doi.org/10.3847/2041-8213%2Faca281

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