The IXPE and multifrequency polarimetric view of the extreme blazars 1ES 1101-232 and RGB J0710+591

Tavecchio F, Kim DE, Emery G, Liodakis I, Agudo I, Coppi P, Tagliaferri G, Di Gesu L, Sbarrato T, Ballo L, Sciaccaluga A, Ehlert SR, Bonnoli G, José Aceituno F, Casadio C, Casanova V, Donnarumma I, Escudero J, Morcuende D, Otero-Santos J, Sota A, Piirola V, Kouch PM, Lindfors E, Nilsson K, Myserlis I, Gurwell M, Keating G, Rao R, Angelakis E, Kraus A, Imazawa R, Sasada M, Fukazawa Y, Kawabata KS, Uemura M, Mizuno T, Nakaoka T, Tochihara S, Akai T, Akitaya H, Bachev R, Strigachev A, Benke P, Debbrecht L, Eich J, Eppel F, Gokus A, Hämmerich S, Heßdörfer J, Kadler M, Kim S, Kirchner D, Paraschos GF, Rösch F, Schulga W (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Book Volume: 709

Article Number: A150

DOI: 10.1051/0004-6361/202558716

Abstract

Multiwavelength polarimetry offers a powerful tool to probe magnetic field and flow geometries in the relativistic jets of blazars. Sources with synchrotron emission that spans a broad frequency range, from radio to X-rays, such as High Synchrotron Peak (HSP) type BL Lac objects, are particularly interesting. Previous measurements including radio, optical, and X-ray data show a clear trend, with the degree of polarization increasing with frequency. Here we report radio, optical, and X-ray observations (Swift, Nustar, and IXPE) of 1ES 1101-232 and RGB J0710+591, two blazars belonging to the puzzling subclass of extreme BL Lacs (EHBL). For 1ES 1101-232, we find a strong frequency dependence of the degree of polarization, with a ratio ΠX/ΠO ≃ 5.2. For RGB J0710+591, IXPE derives a 1σ upper limit ΠX < 11.6%, comparable to the measured optical degree of polarization (average ΠO ∼ 12%). We discuss the results in the framework of current interpretations and, in particular, we report an improved version of the stratified shock model that reproduces the observed data of both sources.

Authors with CRIS profile

Involved external institutions

Institute of Astrophysics of Andalusia / Instituto de Astrofísica de Andalucía (IAA-CSIC) Spain (ES) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) Italy (IT) European Space Astronomy Centre (ESAC) Spain (ES) Italian Space Agency / Agenzia Spaziale Italiana (ASI) Italy (IT) Smithsonian Institution United States (USA) (US) Max-Planck-Institut für Radioastronomie / Max Planck Institute for Radio Astronomy Germany (DE) Julius-Maximilians-Universität Würzburg Germany (DE) Korea Astronomy and Space Science Institute (KASI) Korea, Republic of (KR) Hiroshima University / 広島大学 Japan (JP) Chiba Institute of Technology / 千葉工業大学 Japan (JP) Institute of Astronomy and National Astronomical Observatory / Институт по астрономия Bulgaria (BG) Washington University in St. Louis United States (USA) (US) Yale University United States (USA) (US) Foundation for Research and Technology-Hellas (FORTH) / Ίδρυμα Τεχνολογίας και Έρευνας Greece (GR) National Aeronautics and Space Administration (NASA) United States (USA) (US) Turku University Hospital / Turun yliopistollinen keskussairaala (TYKS) Finland (FI) Instituto de Radioastronomía Milimétrica Spain (ES) Institute of Science Tokyo (ISCT) / 東京科学大学 Japan (JP)

How to cite

APA:

Tavecchio, F., Kim, D.E., Emery, G., Liodakis, I., Agudo, I., Coppi, P.,... Schulga, W. (2026). The IXPE and multifrequency polarimetric view of the extreme blazars 1ES 1101-232 and RGB J0710+591. Astronomy & Astrophysics, 709. https://doi.org/10.1051/0004-6361/202558716

MLA:

Tavecchio, Fabrizio, et al. "The IXPE and multifrequency polarimetric view of the extreme blazars 1ES 1101-232 and RGB J0710+591." Astronomy & Astrophysics 709 (2026).

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