A1 Refereed original research article in a scientific journal
First Sagittarius A* Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring
Authors: Akiyama K, Alberdi A, Alef W, Algaba JC, Anantua R, Asada K, Azulay R, Bach U, Baczko A, Ball D, Baloković M, Bandyopadhyay B, Barrett J, Bauböck M, Benson BA, Bintley D, Blackburn L, Blundell R, Bouman KL, Bower GC, Boyce H, Bremer M, Brinkerink CD, Brissenden R, Britzen S, Broderick AE, Broguiere D, Bronzwaer T, Bustamante S, Byun D, Carlstrom JE, Ceccobello C, Chael A, Chan C, Chang DO, Chatterjee K, Chatterjee S, Chen M, Chen Y, Cheng X, Cho I, Christian P, Conroy NS, Conway JE, Cordes JM, Crawford TM, Crew GB, Cruz-Osorio A, Cui Y, Dahale R, Davelaar J, Laurentis MD, Deane R, Dempsey J, Desvignes G, Dexter J, Dhruv V, Dihingia IK, Doeleman SS, Dougall S, Dzib SA, Eatough RP, Emami R, Falcke H, Farah J, Fish VL, Fomalont E, Ford HA, Foschi M, Fraga-Encinas R, Freeman WT, Friberg P, Fromm CM, Fuentes A, Galison P, Gammie CF, García R, Gentaz O, Georgiev B, Goddi C, Gold R, Gómez-Ruiz AI, Gómez JL, Gu M, Gurwell M, Hada K, Haggard D, Haworth K, Hecht MH, Hesper R, Heumann D, Ho LC, Ho P, Honma M, Huang CL, Huang L, Hughes DH, Ikeda S, Impellizzeri CMV, Inoue M, Issaoun S, James DJ, Jannuzi BT, Janssen M, Jeter B, Jiang W, Jiménez-Rosales A, Johnson MD, Jorstad S, Joshi AV, Jung T, Karami M, Karuppusamy R, Kawashima T, Keating GK, Kettenis M, Kim D, Kim J, Kim J, Kim J, Kino M, Koay JY, Kocherlakota P, Kofuji Y, Koch PM, Koyama S, Kramer C, Kramer JA, Kramer M, Krichbaum TP, Kuo C, Bella NL, Lauer TR, Lee D, Lee S, Leung PK, Levis A, Li Z, Lico R, Lindahl G, Lindqvist M, Lisakov M, Liu J, Liu K, Liuzzo E, Lo W, Lobanov AP, Loinard L, Lonsdale CJ, Lowitz AE, Lu R, MacDonald NR, Mao J, Marchili N, Markoff S, Marrone DP, Marscher AP, Martí-Vidal I, Matsushita S, Matthews LD, Medeiros L, Menten KM, Michalik D, Mizuno I, Mizuno Y, Moran JM, Moriyama K, Moscibrodzka M, Mulaudzi W, Müller C, Müller H, Mus A, Musoke G, Myserlis I, Nadolski A, Nagai H, Nagar NM, Nakamura M, Narayanan G, Natarajan I, Nathanail A, Fuentes SN, Neilsen J, Neri R, Ni C, Noutsos A, Nowak MA, Oh J, Okino H, Olivares H, Ortiz-León GN, Oyama T, Özel F, Palumbo DCM, Paraschos GF, Park J, Parsons H, Patel N, Pen U, Pesce DW, Piétu V, Plambeck R, PopStefanija A, Porth O, Pötzl FM, Prather B, Preciado-López JA, Psaltis D, Pu H, Ramakrishnan V, Rao R, Rawlings MG, Raymond AW, Rezzolla L, Ricarte A, Ripperda B, Roelofs F, Rogers A, Romero-Cañizales C, Ros E, Roshanineshat A, Rottmann H, Roy AL, Ruiz I, Ruszczyk C, Rygl KLJ, Sánchez S, Sánchez-Argüelles D, Sánchez-Portal M, Sasada M, Satapathy K, Savolainen T, Schloerb FP, Schonfeld J, Schuster K, Shao L, Shen Z, Small D, Sohn BW, SooHoo J, Salas LDS, Souccar K, Stanway JS, Sun H, Tazaki F, Tetarenko AJ, Tiede P, Tilanus RPJ, Titus M, Torne P, Toscano T, Traianou E, Trent T, Trippe S, Turk M, Bemmel I, Langevelde HJ, Rossum DR, Vos J, Wagner J, Ward-Thompson D, Wardle J, Washington JE, Weintroub J, Wharton R, Wielgus M, Wiik K, Witzel G, Wondrak MF, Wong GN, Wu Q, Yadlapalli N, Yamaguchi P, Yfantis A, Yoon D, Young A, Young K, Younsi Z, Yu W, Yuan F, Yuan Y, Zensus JA, Zhang S, Zhao G, Zhao S, Najafi-Ziyazi M; Event Horizon Telescope Collaboration
Publisher: Institute of Physics Publishing
Publication year: 2024
Journal: Astrophysical Journal Letters
Journal name in source: The Astrophysical Journal Letters
Article number: L26
Volume: 964
Issue: 2
eISSN: 2041-8213
DOI: https://doi.org/10.3847/2041-8213/ad2df1
Web address : https://dx.doi.org/10.3847/2041-8213/ad2df1
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/387502422
In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%–28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ≈46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow.
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