Comparison of Polarized Radiative Transfer Codes Used by the EHT Collaboration

/ Authors

B. Prather, J. Dexter, M. Mościbrodzka, Hung-Yi Pu, T. Bronzwaer, J. Davelaar, Z. Younsi, C. Gammie, R. Gold, G. Wong

and 263 more authors

K. Akiyama, A. Alberdi, W. Alef, J. Algaba, R. Anantua, K. Asada, R. Azulay, U. Bach, A. Baczko, D. Ball, M. Balokovi'c, J. Barrett, M. Baubock, B. Benson, D. Bintley, L. Blackburn, R. Blundell, K. Bouman, G. Bower, H. Boyce, M. Bremer, C. Brinkerink, R. Brissenden, S. Britzen, A. Broderick, D. Broguiere, S. Bustamante, D. Byun, J. Carlstrom, C. Ceccobello, A. Chael, Chi-kwan Chan, Dominic O. Chang, K. Chatterjee, S. Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, I. Cho, P. Christian, N. S. Conroy, J. Conway, J. Cordes, T. Crawford, G. Crew, A. Cruz-Osorio, Yuzhu Cui, M. Laurentis, R. Deane, J. Dempsey, G. Desvignes, V. Dhruv, S. Doeleman, S. Dougal, S. Dzib, R. Eatough, R. Emami, H. Falcke, J. Farah, V. Fish, E. Fomalont, H. Ford, R. Fraga-Encinas, W. T. Freeman, P. Friberg, C. Fromm, A. Fuentes, P. Galison, Roberto Garc'ia, O. Gentaz, B. Georgiev, C. Goddi, A. I. G'omez-Ruiz, Jos'e L. G'omez, M. Gu, M. Gurwell, K. Hada, D. Haggard, K. Haworth, M. Hecht, R. Hesper, D. Heumann, L. Ho, P. Ho, M. Honma, Chih-Wei L. Huang, Lei Huang, D. Hughes, Shiro Ikeda, C. Impellizzeri, M. Inoue, S. Issaoun, David J. James, B. Jannuzi, M. Janssen, B. Jeter, Wu Jiang, A. Jim'enez-Rosales, Michael D. Johnson, S. Jorstad, A. Joshi, T. Jung, M. Karami, R. Karuppusamy, T. Kawashima, G. Keating, M. Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, M. Kino, J. Koay, Prashant Kocherlakota, Y. Kofuji, S. Koyama, C. Kramer, M. Kramer, T. Krichbaum, C. Kuo, N. L. Bella, T. Lauer, Daeyoung Lee, Sang-Sung Lee, P. Leung, A. Levis, Zhiyuan Li, R. Lico, Greg Lindahl, M. Lindqvist, M. Lisakov, Jun Liu, Kuo Liu, E. Liuzzo, Wen-Ping Lo, A. Lobanov, L. Loinard, C. Lonsdale, Ruohan Lu, N. MacDonald, J. Mao, N. Marchili, S. Markoff, D. Marrone, A. Marscher, Iv'an Mart'i-Vidal, S. Matsushita, L. Matthews, L. Medeiros, K. Menten, D. Michalik, I. Mizuno, Y. Mizuno, J. Moran, K. Moriyama, C. Muller, A. Mus, G. Musoke, I. Myserlis, A. Nadolski, H. Nagai, N. Nagar, M. Nakamura, R. Narayan, G. Narayanan, I. Natarajan, A. Nathanail, S. N. Fuentes, J. Neilsen, R. Neri, C. Ni, A. Noutsos, M. Nowak, Junghwan Oh, H. Okino, H. Olivares, G. Ortiz-Le'on, T. Oyama, F. Ozel, D. Palumbo, G. Paraschos, Jongho Park, H. Parsons, N. Patel, U. Pen, D. Pesce, V. Pi'etu, R. Plambeck, A. PopStefanija, O. Porth, F. Potzl, J. A. Preciado-L'opez, D. Psaltis, V. Ramakrishnan, R. Rao, M. Rawlings, A. Raymond, L. Rezzolla, A. Ricarte, B. Ripperda, F. Roelofs, Alan Rogers, Eduardo Ros, C. Romero-Cañizales, A. Roshanineshat, H. Rottmann, A. Roy, I. Ruiz, C. Ruszczyk, K. Rygl, S. S'anchez, D. S'anchez-Arguelles, M. S'anchez-Portal, M. Sasada, K. Satapathy, T. Savolainen, F. Schloerb, J. Schonfeld, K. Schuster, Lijing Shao, Zhiqiang Shen, D. Small, B. Sohn, J. SooHoo, K. Souccar, He Sun, F. Tazaki, A. Tetarenko, P. Tiede, R. Tilanus, M. Titus, P. Torne, E. Traianou, T. Trent, S. Trippe, Matthew A. Turk, I. Bemmel, H. V. Langevelde, D. V. Rossum, J. Vos, J. Wagner, D. Ward-Thompson, J. Wardle, J. Weintroub, N. Wex, R. Wharton, M. Wielgus, K. Wiik, G. Witzel, M. Wondrak, Qingwen Wu, P. Yamaguchi, A. Yfantis, D. Yoon, A. Young, K. Young, Wei Yu, F. Yuan, Ye-Fei Yuan, J. Zensus, Shuo Zhang, Guangyao Zhao, Shan-Shan Zhao

/ Abstract

Interpretation of resolved polarized images of black holes by the Event Horizon Telescope (EHT) requires predictions of the polarized emission observable by an Earth-based instrument for a particular model of the black hole accretion system. Such predictions are generated by general relativistic radiative transfer (GRRT) codes, which integrate the equations of polarized radiative transfer in curved spacetime. A selection of ray-tracing GRRT codes used within the EHT Collaboration is evaluated for accuracy and consistency in producing a selection of test images, demonstrating that the various methods and implementations of radiative transfer calculations are highly consistent. When imaging an analytic accretion model, we find that all codes produce images similar within a pixel-wise normalized mean squared error (NMSE) of 0.012 in the worst case. When imaging a snapshot from a cell-based magnetohydrodynamic simulation, we find all test images to be similar within NMSEs of 0.02, 0.04, 0.04, and 0.12 in Stokes I, Q, U, and V, respectively. We additionally find the values of several image metrics relevant to published EHT results to be in agreement to much better precision than measurement uncertainties.

Journal: The Astrophysical Journal

DOI: 10.3847/1538-4357/acc586