A Two-Week $IXPE$ Monitoring Campaign on Mrk 421
Abstract
X-ray polarization is a unique new probe of the particle acceleration in astrophysical jets made possible through the Imaging X-ray Polarimetry Explorer. Here we report on the first dense X-ray polarization monitoring campaign on the blazar Mrk 421. Our observations were accompanied by an even denser radio and optical polarization campaign. We find significant short-timescale variability in both X-ray polarization degree and angle, including a angle rotation about the jet axis. We attribute this to random variations of the magnetic field, consistent with the presence of turbulence but also unlikely to be explained by turbulence alone. At the same time, the degree of lower-energy polarization is significantly lower and shows no more than mild variability. Our campaign provides further evidence for a scenario in which energy-stratified shock-acceleration of relativistic electrons, combined with a turbulent magnetic field, is responsible for optical to X-ray synchrotron emission in blazar jets.
Cite
@article{arxiv.2410.19983,
title = {A Two-Week $IXPE$ Monitoring Campaign on Mrk 421},
author = {W. Peter Maksym and Ioannis Liodakis and M. Lynne Saade and Dawoon E. Kim and Riccardo Middei and Laura Di Gesu and Sebastian Kiehlmann and Gabriele Matzeu and Iván Agudo and Alan P. Marscher and Steven R. Ehlert and Svetlana G. Jorstad and Philip Kaaret and Herman L. Marshall and Luigi Pacciani and Matteo Perri and Simonetta Puccetti and Pouya M. Kouch and Elina Lindfors and Francisco José Aceituno and Giacomo Bonnoli and Víctor Casanova and Juan Escudero and Beatriz Agís-González and César Husillos and Daniel Morcuende and Jorge Otero-Santos and Alfredo Sota and Vilppu Piirola and Ryo Imazawa and Mahito Sasada and Yasushi Fukazawa and Koji S. Kawabata and Makoto Uemura and Tsunefumi Mizuno and Tatsuya Nakaoka and Hiroshi Akitaya and Callum McCall and Helen E. Jermak and Iain A. Steele and George A. Borman and Tatiana S. Grishina and Vladimir A. Hagen-Thorn and Evgenia N. Kopatskaya and Elena G. Larionova and Daria A. Morozova and Sergey S. Savchenko and Ekaterina V. Shishkina and Ivan S. Troitskiy and Yulia V. Troitskaya and Andrey A. Vasilyev and Alexey V. Zhovtan and Ioannis Myserlis and Mark Gurwell and Garrett Keating and Ramprasad Rao and Colt Pauley and Emmanouil Angelakis and Alexander Kraus and Andrei V. Berdyugin and Masato Kagitani and Vadim Kravtsov and Juri Poutanen and Takeshi Sakanoi and Sincheol Kang and Sang-Sung Lee and Sang-Hyun Kim and Whee Yeon Cheong and Hyeon-Woo Jeong and Chanwoo Song and Dmitry Blinov and Elena Shablovinskaya and Lucio Angelo Antonelli and Matteo Bachetti and Luca Baldini and Wayne H. Baumgartner and Ronaldo Bellazzini and Stefano Bianchi and Stephen D. Bongiorno and Raffaella Bonino and Alessandro Brez and Niccoló Bucciantini and Fiamma Capitanio and Simone Castellano and Elisabetta Cavazzuti and Chien-Ting Chen and Stefano Ciprini and Enrico Costa and Alessandra De Rosa and Ettore Del Monte and Niccoló Di Lalla and Alessandro Di Marco and Immacolata Donnarumma and Victor Doroshenko and Michal Dovčiak and Teruaki Enoto and Yuri Evangelista and Sergio Fabiani and Riccardo Ferrazzoli and Javier A. Garcia and Shuichi Gunji and Kiyoshi Hayashida and Jeremy Heyl and Wataru Iwakiri and Vladimir Karas and Fabian Kislat and Takao Kitaguchi and Jeffery J. Kolodziejczak and Henric Krawczynski and Fabio La Monaca and Luca Latronico and Simone Maldera and Alberto Manfreda and Frédéric Marin and Andrea Marinucci and Francesco Massaro and Giorgio Matt and Ikuyuki Mitsuishi and Fabio Muleri and Michela Negro and C. -Y. Ng and Stephen L. O'Dell and Nicola Omodei and Chiara Oppedisano and Alessandro Papitto and George G. Pavlov and Abel Lawrence Peirson and Melissa Pesce-Rollins and Pierre-Olivier Petrucci and Maura Pilia and Andrea Possenti and Brian D. Ramsey and John Rankin and Ajay Ratheesh and Oliver J. Roberts and Roger W. Romani and Carmelo Sgró and Patrick Slane and Paolo Soffitta and Gloria Spandre and Douglas A. Swartz and Toru Tamagawa and Fabrizio Tavecchio and Roberto Taverna and Yuzuru Tawara and Allyn F. Tennant and Nicholas E. Thomas and Francesco Tombesi and Alessio Trois and Sergey S. Tsygankov and Roberto Turolla and Jacco Vink and Martin C. Weisskopf and Kinwah Wu and Fei Xie and Silvia Zane},
journal= {arXiv preprint arXiv:2410.19983},
year = {2024}
}
Comments
23 pages, including 8 pages of appendices. 12 figures, 3 tables. Submitted to ApJ