Title: | Polarimetric Properties of Event Horizon Telescope Targets from ALMA |
Authors: | GODDI, CIRIACO Martí-Vidal, Iván Messias, Hugo Bower, Geoffrey C. Broderick, Avery E. Dexter, Jason Marrone, Daniel P. Moscibrodzka, Monika Nagai, Hiroshi Algaba, Juan Carlos Asada, Keiichi Crew, Geoffrey B. Gómez, José L. Impellizzeri, C. M. Violette Janssen, Michael Kadler, Matthias Krichbaum, Thomas P. LICO, Rocco Matthews, Lynn D. Nathanail, Antonios Ricarte, Angelo Ros, Eduardo Younsi, Ziri Akiyama, Kazunori Alberdi, Antxon Alef, Walter Anantua, Richard Azulay, Rebecca Baczko, Anne-Kathrin Ball, David Baloković, Mislav Barrett, John Benson, Bradford A. Bintley, Dan Blackburn, Lindy Blundell, Raymond Boland, Wilfred Bouman, Katherine L. Boyce, Hope Bremer, Michael Brinkerink, Christiaan D. Brissenden, Roger Britzen, Silke Broguiere, Dominique Bronzwaer, Thomas Byun, Do-Young Carlstrom, John E. Chael, Andrew Chan, Chi-kwan Chatterjee, Shami Chatterjee, Koushik Chen, Ming-Tang Chen, Yongjun Chesler, Paul M. Cho, Ilje Christian, Pierre Conway, John E. Cordes, James M. Crawford, Thomas M. Cruz-Osorio, Alejandro Cui, Yuzhu Davelaar, Jordy De Laurentis, Mariafelicia Deane, Roger Dempsey, Jessica Desvignes, Gregory Doeleman, Sheperd S. Eatough, Ralph P. Falcke, Heino Farah, Joseph Fish, Vincent L. Fomalont, Ed Ford, H. Alyson Fraga-Encinas, Raquel Freeman, William T. Friberg, Per Fromm, Christian M. Fuentes, Antonio Galison, Peter Gammie, Charles F. García, Roberto Gentaz, Olivier Georgiev, Boris Gold, Roman Gómez-Ruiz, Arturo I. Gu, Minfeng Gurwell, Mark Hada, Kazuhiro Haggard, Daryl Hecht, Michael H. Hesper, Ronald Ho, Luis C. Ho, Paul Honma, Mareki Huang, Chih-Wei L. Huang, Lei Hughes, David H. Inoue, Makoto Issaoun, Sara James, David J. Jannuzi, Buell T. Jeter, Britton Jiang, Wu Jimenez-Rosales, Alejandra Johnson, Michael D. Jorstad, Svetlana Jung, Taehyun Karami, Mansour Karuppusamy, Ramesh Kawashima, Tomohisa Keating, Garrett K. Kettenis, Mark Kim, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kino, Motoki Koay, Jun Yi Kofuji, Yutaro Koch, Patrick M. Koyama, Shoko Kramer, Michael Kramer, Carsten Kuo, Cheng-Yu Lauer, Tod R. Lee, Sang-Sung Levis, Aviad Li, Yan-Rong Li, Zhiyuan Lindqvist, Michael Lindahl, Greg Liu, Jun Liu, Kuo LIUZZO, Elisabetta Teodorina Lo, Wen-Ping Lobanov, Andrei P. Loinard, Laurent Lonsdale, Colin Lu, Ru-Sen MacDonald, Nicholas R. Mao, Jirong MARCHILI, Nicola Markoff, Sera Marscher, Alan P. Matsushita, Satoki Medeiros, Lia Menten, Karl M. Mizuno, Izumi Mizuno, Yosuke Moran, James M. Moriyama, Kotaro Müller, Cornelia Musoke, Gibwa Mejías, Alejandro Mus Nagar, Neil M. Nakamura, Masanori Narayan, Ramesh Narayanan, Gopal Natarajan, Iniyan Neilsen, Joey Neri, Roberto Ni, Chunchong Noutsos, Aristeidis Nowak, Michael A. Okino, Hiroki Olivares, Héctor Ortiz-León, Gisela N. Oyama, Tomoaki Özel, Feryal Palumbo, Daniel C. M. Park, Jongho Patel, Nimesh Pen, Ue-Li Pesce, Dominic W. Piétu, Vincent Plambeck, Richard PopStefanija, Aleksandar Porth, Oliver Pötzl, Felix M. Prather, Ben Preciado-López, Jorge A. Psaltis, Dimitrios Pu, Hung-Yi Ramakrishnan, Venkatessh Rao, Ramprasad Rawlings, Mark G. Raymond, Alexander W. Rezzolla, Luciano Ripperda, Bart Roelofs, Freek Rogers, Alan Rose, Mel Roshanineshat, Arash Rottmann, Helge Roy, Alan L. Ruszczyk, Chet RYGL, Kazi Lucie Jessica Sánchez, Salvador Sánchez-Arguelles, David Sasada, Mahito Savolainen, Tuomas Schloerb, F. Peter Schuster, Karl-Friedrich Shao, Lijing Shen, Zhiqiang Small, Des Sohn, Bong Won SooHoo, Jason Sun, He Tazaki, Fumie Tetarenko, Alexandra J. Tiede, Paul Tilanus, Remo P. J. Titus, Michael Toma, Kenji Torne, Pablo Trent, Tyler Traianou, Efthalia Trippe, Sascha van Bemmel, Ilse van Langevelde, Huib Jan van Rossum, Daniel R. Wagner, Jan Ward-Thompson, Derek Wardle, John Weintroub, Jonathan Wex, Norbert Wharton, Robert Wielgus, Maciek Wong, George N. Wu, Qingwen Yoon, Doosoo Young, André Young, Ken Yuan, Feng Yuan, Ye-Fei Zensus, J. Anton Zhao, Guang-Yao Zhao, Shan-Shan Bruni, Gabriele Gopakumar, A. Hernández-Gómez, Antonio Herrero-Illana, Ruben Ingram, Adam Komossa, S. Kovalev, Y. Y. Muders, Dirk Perucho, Manel Rösch, Florian Valtonen, Mauri |
Issue Date: | 2021 |
Journal: | THE ASTROPHYSICAL JOURNAL LETTERS |
Number: | 910 |
Issue: | 1 |
First Page: | L14 |
Abstract: | We present the results from a full polarization study carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) during the first Very Long Baseline Interferometry (VLBI) campaign, which was conducted in 2017 April in the λ3 mm and λ1.3 mm bands, in concert with the Global mm-VLBI Array (GMVA) and the Event Horizon Telescope (EHT), respectively. We determine the polarization and Faraday properties of all VLBI targets, including Sgr A*, M87, and a dozen radio-loud active galactic nuclei (AGNs), in the two bands at several epochs in a time window of 10 days. We detect high linear polarization fractions (2%-15%) and large rotation measures (RM > 10<SUP>3.3</SUP>-10<SUP>5.5</SUP> rad m<SUP>-2</SUP>), confirming the trends of previous AGN studies at millimeter wavelengths. We find that blazars are more strongly polarized than other AGNs in the sample, while exhibiting (on average) order-of-magnitude lower RM values, consistent with the AGN viewing angle unification scheme. For Sgr A* we report a mean RM of (-4.2 ± 0.3) × 10<SUP>5</SUP> rad m<SUP>-2</SUP> at 1.3 mm, consistent with measurements over the past decade and, for the first time, an RM of (-2.1 ± 0.1) × 10<SUP>5</SUP> rad m<SUP>-2</SUP> at 3 mm, suggesting that about half of the Faraday rotation at 1.3 mm may occur between the 3 mm photosphere and the 1.3 mm source. We also report the first unambiguous measurement of RM toward the M87 nucleus at millimeter wavelengths, which undergoes significant changes in magnitude and sign reversals on a one year timescale, spanning the range from -1.2 to 0.3 × 10<SUP>5</SUP> rad m<SUP>-2</SUP> at 3 mm and -4.1 to 1.5 × 10<SUP>5</SUP> rad m<SUP>-2</SUP> at 1.3 mm. Given this time variability, we argue that, unlike the case of Sgr A*, the RM in M87 does not provide an accurate estimate of the mass accretion rate onto the black hole. We put forward a two-component model, comprised of a variable compact region and a static extended region, that can simultaneously explain the polarimetric properties observed by both the EHT (on horizon scales) and ALMA (which observes the combined emission from both components). These measurements provide critical constraints for the calibration, analysis, and interpretation of simultaneously obtained VLBI data with the EHT and GMVA. |
URI: | http://hdl.handle.net/20.500.12386/31834 |
URL: | https://iopscience.iop.org/article/10.3847/2041-8213/abee6a https://api.elsevier.com/content/abstract/scopus_id/85103664771 |
ISSN: | 2041-8205 |
DOI: | 10.3847/2041-8213/abee6a |
Bibcode ADS: | 2021ApJ...910L..14G |
Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista
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