First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA

Ciriaco Goddi; Douglas Ferreira Carlos; Geoffrey B. Crew; Lynn D. Matthews; Hugo Messias; Alejandro Mus; Iván Martí-Vidal; Ezequiel Albentosa-Ruíz; Mariafelicia De Laurentis; Elisabetta Liuzzo; Nicola Marchili; Kazi L. J. Rygl; Kazunori Akiyama; Antxon Alberdi; Walter Alef; Juan Carlos Algaba; Richard Anantua; Keiichi Asada; Rebecca Azulay; Uwe Bach; Anne-Kathrin Baczko; David Ball; Mislav Balokoviä; Bidisha Bandyopadhyay; John Barrett; Michi Bauböck; Bradford A. Benson; Dan Bintley; Lindy Blackburn; Raymond Blundell; Katherine L. Bouman; Geoffrey C. Bower; Michael Bremer; Roger Brissenden; Silke Britzen; Avery E. Broderick; Dominique Broguiere; Thomas Bronzwaer; Sandra Bustamante; John E. Carlstrom; Andrew A. Chael; Chi-kwan Chan; Dominic O. Chang; Koushik Chatterjee; Shami Chatterjee; Ming Tang Chen; Yongjun Chen; Xiaopeng Cheng; Ilje Cho; Pierre Christian

doi:10.1051/0004-6361/202554140

First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA

Ciriaco Goddi^*
, Douglas Ferreira Carlos
, Geoffrey B. Crew
, Lynn D. Matthews
, Hugo Messias
, Alejandro Mus
, Iván Martí-Vidal
, Ezequiel Albentosa-Ruíz
, Mariafelicia De Laurentis
, Elisabetta Liuzzo
, Nicola Marchili
, Kazi L. J. Rygl
, Kazunori Akiyama
, Antxon Alberdi
, Walter Alef
, Juan Carlos Algaba
, Richard Anantua
, Keiichi Asada
, Rebecca Azulay
, Uwe Bach

Anne-Kathrin Baczko, David Ball, Mislav Balokoviä, Bidisha Bandyopadhyay, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Michael Bremer, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, John E. Carlstrom, Andrew A. Chael, Chi-kwan Chan, Dominic O. Chang, Koushik Chatterjee, Shami Chatterjee, Ming Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre Christian

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

6 Citations (Scopus)

Abstract

Aims. We investigated the polarization and Faraday properties of Messier 87 (M87) and seven other radio-loud active galactic nuclei (AGNs) at _0.87mm (345 GHz) using the Atacama Large Millimeter/submillimeter Array (ALMA). Our goal was to characterize the linear polarization (LP) fractions, measure Faraday rotation measures (RMs), and examine the magnetic field structures in the emission regions of these AGNs.

Methods. We conducted full-polarization observations as part of the ALMA Band 7 very long baseline interferometry (VLBI) commissioning during the April 2021 Event Horizon Telescope (EHT) campaign. We analyzed the LP fractions and RMs to assess the nature of Faraday screens and magnetic fields in the submillimeter emission regions.

Results. We find LP fractions between 1% and 17% and RMs exceeding 105 radm-2, which are 1-2 orders of magnitude higher than typically observed at longer wavelengths (λ > 3 mm). This suggests denser Faraday screens or stronger magnetic fields. Additionally, we present the first submillimeter polarized images of the M87 jet and the observed AGNs, revealing RM gradients and sign reversals in the M87 jet indicative of a kiloparsec-scale helical magnetic field structure.

Conclusions. Our results provide essential constraints for calibrating, analyzing, and interpreting VLBI data from the EHT at 345 GHz, representing a critical step toward submillimeter VLBI imaging.

Original language	English
Article number	A265
Journal	Astronomy and Astrophysics
Volume	699
DOIs	https://doi.org/10.1051/0004-6361/202554140
Publication status	Published - 17 Jul 2025

Keywords

Black hole physics
Instrumentation: interferometers
Instrumentation: polarimeters
Magnetic fields
Polarization
Radiation mechanisms: non-thermal

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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Goddi, C., Carlos, D. F., Crew, G. B., Matthews, L. D., Messias, H., Mus, A., Martí-Vidal, I., Albentosa-Ruíz, E., De Laurentis, M., Liuzzo, E., Marchili, N., Rygl, K. L. J., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., ... Christian, P. (2025). First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA. Astronomy and Astrophysics, 699, Article A265. https://doi.org/10.1051/0004-6361/202554140

@article{0ff7469f020e4db48b9830190c154751,

title = "First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA",

abstract = "Aims. We investigated the polarization and Faraday properties of Messier 87 (M87) and seven other radio-loud active galactic nuclei (AGNs) at \_0.87mm (345 GHz) using the Atacama Large Millimeter/submillimeter Array (ALMA). Our goal was to characterize the linear polarization (LP) fractions, measure Faraday rotation measures (RMs), and examine the magnetic field structures in the emission regions of these AGNs. Methods. We conducted full-polarization observations as part of the ALMA Band 7 very long baseline interferometry (VLBI) commissioning during the April 2021 Event Horizon Telescope (EHT) campaign. We analyzed the LP fractions and RMs to assess the nature of Faraday screens and magnetic fields in the submillimeter emission regions. Results. We find LP fractions between 1\% and 17\% and RMs exceeding 105 radm-2, which are 1-2 orders of magnitude higher than typically observed at longer wavelengths (λ > 3 mm). This suggests denser Faraday screens or stronger magnetic fields. Additionally, we present the first submillimeter polarized images of the M87 jet and the observed AGNs, revealing RM gradients and sign reversals in the M87 jet indicative of a kiloparsec-scale helical magnetic field structure. Conclusions. Our results provide essential constraints for calibrating, analyzing, and interpreting VLBI data from the EHT at 345 GHz, representing a critical step toward submillimeter VLBI imaging.",

keywords = "Black hole physics, Instrumentation: interferometers, Instrumentation: polarimeters, Magnetic fields, Polarization, Radiation mechanisms: non-thermal",

author = "Ciriaco Goddi and Carlos, \{Douglas Ferreira\} and Crew, \{Geoffrey B.\} and Matthews, \{Lynn D.\} and Hugo Messias and Alejandro Mus and Iv{\'a}n Mart{\'i}-Vidal and Ezequiel Albentosa-Ru{\'i}z and \{De Laurentis\}, Mariafelicia and Elisabetta Liuzzo and Nicola Marchili and Rygl, \{Kazi L. J.\} and Kazunori Akiyama and Antxon Alberdi and Walter Alef and Algaba, \{Juan Carlos\} and Richard Anantua and Keiichi Asada and Rebecca Azulay and Uwe Bach and Anne-Kathrin Baczko and David Ball and Mislav Balokovi{\"a} and Bidisha Bandyopadhyay and John Barrett and Michi Baub{\"o}ck and Benson, \{Bradford A.\} and Dan Bintley and Lindy Blackburn and Raymond Blundell and Bouman, \{Katherine L.\} and Bower, \{Geoffrey C.\} and Michael Bremer and Roger Brissenden and Silke Britzen and Broderick, \{Avery E.\} and Dominique Broguiere and Thomas Bronzwaer and Sandra Bustamante and Carlstrom, \{John E.\} and Chael, \{Andrew A.\} and Chi-kwan Chan and Chang, \{Dominic O.\} and Koushik Chatterjee and Shami Chatterjee and Chen, \{Ming Tang\} and Yongjun Chen and Xiaopeng Cheng and Ilje Cho and Pierre Christian",

year = "2025",

month = jul,

day = "17",

doi = "10.1051/0004-6361/202554140",

language = "English",

volume = "699",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

}

Goddi, C, Carlos, DF, Crew, GB, Matthews, LD, Messias, H, Mus, A, Martí-Vidal, I, Albentosa-Ruíz, E, De Laurentis, M, Liuzzo, E, Marchili, N, Rygl, KLJ, Akiyama, K, Alberdi, A, Alef, W, Algaba, JC, Anantua, R, Asada, K, Azulay, R, Bach, U, Baczko, A-K, Ball, D, Balokoviä, M, Bandyopadhyay, B, Barrett, J, Bauböck, M, Benson, BA, Bintley, D, Blackburn, L, Blundell, R, Bouman, KL, Bower, GC, Bremer, M, Brissenden, R, Britzen, S, Broderick, AE, Broguiere, D, Bronzwaer, T, Bustamante, S, Carlstrom, JE, Chael, AA, Chan, C, Chang, DO, Chatterjee, K, Chatterjee, S, Chen, MT, Chen, Y, Cheng, X, Cho, I & Christian, P 2025, 'First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA', Astronomy and Astrophysics, vol. 699, A265. https://doi.org/10.1051/0004-6361/202554140

TY - JOUR

T1 - First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA

AU - Goddi, Ciriaco

AU - Carlos, Douglas Ferreira

AU - Crew, Geoffrey B.

AU - Matthews, Lynn D.

AU - Messias, Hugo

AU - Mus, Alejandro

AU - Martí-Vidal, Iván

AU - Albentosa-Ruíz, Ezequiel

AU - De Laurentis, Mariafelicia

AU - Liuzzo, Elisabetta

AU - Marchili, Nicola

AU - Rygl, Kazi L. J.

AU - Akiyama, Kazunori

AU - Alberdi, Antxon

AU - Alef, Walter

AU - Algaba, Juan Carlos

AU - Anantua, Richard

AU - Asada, Keiichi

AU - Azulay, Rebecca

AU - Bach, Uwe

AU - Baczko, Anne-Kathrin

AU - Ball, David

AU - Balokoviä, Mislav

AU - Bandyopadhyay, Bidisha

AU - Barrett, John

AU - Bauböck, Michi

AU - Benson, Bradford A.

AU - Bintley, Dan

AU - Blackburn, Lindy

AU - Blundell, Raymond

AU - Bouman, Katherine L.

AU - Bower, Geoffrey C.

AU - Bremer, Michael

AU - Brissenden, Roger

AU - Britzen, Silke

AU - Broderick, Avery E.

AU - Broguiere, Dominique

AU - Bronzwaer, Thomas

AU - Bustamante, Sandra

AU - Carlstrom, John E.

AU - Chael, Andrew A.

AU - Chan, Chi-kwan

AU - Chang, Dominic O.

AU - Chatterjee, Koushik

AU - Chatterjee, Shami

AU - Chen, Ming Tang

AU - Chen, Yongjun

AU - Cheng, Xiaopeng

AU - Cho, Ilje

AU - Christian, Pierre

PY - 2025/7/17

Y1 - 2025/7/17

N2 - Aims. We investigated the polarization and Faraday properties of Messier 87 (M87) and seven other radio-loud active galactic nuclei (AGNs) at _0.87mm (345 GHz) using the Atacama Large Millimeter/submillimeter Array (ALMA). Our goal was to characterize the linear polarization (LP) fractions, measure Faraday rotation measures (RMs), and examine the magnetic field structures in the emission regions of these AGNs. Methods. We conducted full-polarization observations as part of the ALMA Band 7 very long baseline interferometry (VLBI) commissioning during the April 2021 Event Horizon Telescope (EHT) campaign. We analyzed the LP fractions and RMs to assess the nature of Faraday screens and magnetic fields in the submillimeter emission regions. Results. We find LP fractions between 1% and 17% and RMs exceeding 105 radm-2, which are 1-2 orders of magnitude higher than typically observed at longer wavelengths (λ > 3 mm). This suggests denser Faraday screens or stronger magnetic fields. Additionally, we present the first submillimeter polarized images of the M87 jet and the observed AGNs, revealing RM gradients and sign reversals in the M87 jet indicative of a kiloparsec-scale helical magnetic field structure. Conclusions. Our results provide essential constraints for calibrating, analyzing, and interpreting VLBI data from the EHT at 345 GHz, representing a critical step toward submillimeter VLBI imaging.

AB - Aims. We investigated the polarization and Faraday properties of Messier 87 (M87) and seven other radio-loud active galactic nuclei (AGNs) at _0.87mm (345 GHz) using the Atacama Large Millimeter/submillimeter Array (ALMA). Our goal was to characterize the linear polarization (LP) fractions, measure Faraday rotation measures (RMs), and examine the magnetic field structures in the emission regions of these AGNs. Methods. We conducted full-polarization observations as part of the ALMA Band 7 very long baseline interferometry (VLBI) commissioning during the April 2021 Event Horizon Telescope (EHT) campaign. We analyzed the LP fractions and RMs to assess the nature of Faraday screens and magnetic fields in the submillimeter emission regions. Results. We find LP fractions between 1% and 17% and RMs exceeding 105 radm-2, which are 1-2 orders of magnitude higher than typically observed at longer wavelengths (λ > 3 mm). This suggests denser Faraday screens or stronger magnetic fields. Additionally, we present the first submillimeter polarized images of the M87 jet and the observed AGNs, revealing RM gradients and sign reversals in the M87 jet indicative of a kiloparsec-scale helical magnetic field structure. Conclusions. Our results provide essential constraints for calibrating, analyzing, and interpreting VLBI data from the EHT at 345 GHz, representing a critical step toward submillimeter VLBI imaging.

KW - Black hole physics

KW - Instrumentation: interferometers

KW - Instrumentation: polarimeters

KW - Magnetic fields

KW - Polarization

KW - Radiation mechanisms: non-thermal

UR - https://www.scopus.com/pages/publications/105011594266

U2 - 10.1051/0004-6361/202554140

DO - 10.1051/0004-6361/202554140

M3 - Article

AN - SCOPUS:105011594266

SN - 0004-6361

VL - 699

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A265

ER -

First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA

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