DOI

  • Chien-Ting J. Chen
  • Ioannis Liodakis
  • Riccardo Middei
  • Dawoon E. Kim
  • Laura Di Gesu
  • Alessandro Di Marco
  • Steven R. Ehlert
  • Manel Errando
  • Michela Negro
  • Alan P. Marscher
  • Kinwah Wu
  • Iván Agudo
  • Juri Poutanen
  • Tsunefumi Mizuno
  • Pouya M. Kouch
  • Elina Lindfors
  • George A. Borman
  • Alexey V. Zhovtan
  • Francisco José Aceituno
  • Giacomo Bonnoli
  • Víctor Casanova
  • Juan Escudero
  • Beatriz Agís-González
  • César Husillos
  • Jorge Otero Santos
  • Alfredo Sota
  • Vilppu Piirola
  • Ioannis Myserlis
  • Emmanouil Angelakis
  • Alexander Kraus
  • Mark Gurwell
  • Garrett Keating
  • Ramprasad Rao
  • Sincheol Kang
  • Sang-Sung Lee
  • Sang-Hyun Kim
  • Whee Yeon Cheong
  • Hyeon-Woo Jeong
  • Chanwoo Song
  • Andrei V. Berdyugin
  • Masato Kagitani
  • Vadim Kravtsov
  • Anagha P. Nitindala
  • Takeshi Sakanoi
  • Ryo Imazawa
  • Mahito Sasada
  • Yasushi Fukazawa
  • Koji S. Kawabata
  • Makoto Uemura
  • Tatsuya Nakaoka
  • Hiroshi Akitaya
  • Carolina Casadio
  • Albrecht Sievers
  • Lucio Angelo 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
  • Elisabetta Cavazzuti
  • Stefano Ciprini
  • Enrico Costa
  • Alessandra De Rosa
  • Ettore Del Monte
  • Niccoló Di Lalla
  • Immacolata Donnarumma
  • Victor Doroshenko
  • Michal Dovčiak
  • Teruaki Enoto
  • Yuri Evangelista
  • Sergio Fabiani
  • Riccardo Ferrazzoli
  • Javier A. Garcia
  • Shuichi Gunji
  • Kiyoshi Hayashida
  • Jeremy Heyl
  • Wataru Iwakiri
  • Philip Kaaret
  • Vladimir Karas
  • Fabian Kislat
  • Takao Kitaguchi
  • Jeffery J. Kolodziejczak
  • Henric Krawczynski
  • Fabio La Monaca
  • Luca Latronico
  • Simone Maldera
  • Alberto Manfreda
  • Frédéric Marin
  • Andrea Marinucci
  • Herman L. Marshall
  • Francesco Massaro
  • Giorgio Matt
  • Ikuyuki Mitsuishi
  • Fabio Muleri
  • C.-Y. Ng
  • Stephen L. O’Dell
  • Nicola Omodei
  • Chiara Oppedisano
  • Alessandro Papitto
  • George G. Pavlov
  • Abel Lawrence Peirson
  • Matteo Perri
  • Melissa Pesce-Rollins
  • Pierre-Olivier Petrucci
  • Maura Pilia
  • Andrea Possenti
  • Simonetta Puccetti
  • Brian D. Ramsey
  • John Rankin
  • Ajay Ratheesh
  • Oliver J. Roberts
  • Roger W. Romani
  • Carmelo Sgró
  • Patrick Slane
  • Paolo Soffitta
  • Gloria Spandre
  • Douglas A. Swartz
  • Toru Tamagawa
  • Fabrizio Tavecchio
  • Roberto Taverna
  • Yuzuru Tawara
  • Allyn F. Tennant
  • Nicholas E. Thomas
  • Francesco Tombesi
  • Alessio Trois
  • Sergey S. Tsygankov
  • Roberto Turolla
  • Jacco Vink
  • Martin C. Weisskopf
  • Fei Xie
  • Silvia Zane
We present multiwavelength polarization measurements of the luminous blazar Mrk 501 over a 14 month period. The 2–8 keV X-ray polarization was measured with the Imaging X-ray Polarimetry Explorer (IXPE) with six 100 ks observations spanning from 2022 March to 2023 April. Each IXPE observation was accompanied by simultaneous X-ray data from NuSTAR, Swift/XRT, and/or XMM-Newton. Complementary optical–infrared polarization measurements were also available in the B, V, R, I, and J bands, as were radio polarization measurements from 4.85 GHz to 225.5 GHz. Among the first five IXPE observations, we did not find significant variability in the X-ray polarization degree and angle with IXPE. However, the most recent sixth observation found an elevated polarization degree at >3σ above the average of the other five observations. The optical and radio measurements show no apparent correlations with the X-ray polarization properties. Throughout the six IXPE observations, the X-ray polarization degree remained higher than, or similar to, the R-band optical polarization degree, which remained higher than the radio value. This is consistent with the energy-stratified shock scenario proposed to explain the first two IXPE observations, in which the polarized X-ray, optical, and radio emission arises from different regions.
Original languageEnglish
Article number50
JournalThe Astrophysical Journal
Volume974
Issue number1
DOIs
StatePublished - 1 Oct 2024

ID: 125708114