Author: "John Kuroda" - Searchworks@Jio Institute Digital Library Search Results

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1. Implementation of automated vanilla pollination robotic crane prototype.

Author: Tuan Giang, John Kuroda, and Ted Shaneyfelt
Published: 2017
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2. Development of digital sideband separating down-conversion for Yuan-Tseh Lee Array

Author: Ranjani Srinivasan, Jen-Chieh Cheng, Ming-Tang Chen, John Kuroda, Kim Guzzino, Chao-Te Li, Derek Kubo, and Solomon Ho
Subjects: Physics, 010504 meteorology & atmospheric sciences, Sideband, business.industry, Bandwidth (signal processing), Independent sideband, FOS: Physical sciences, High-electron-mobility transistor, 01 natural sciences, Front and back ends, Optics, 0103 physical sciences, Baseband, business, Telecommunications, Compatible sideband transmission, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Monolithic microwave integrated circuit, 0105 earth and related environmental sciences
Abstract: This report presents a down-conversion method involving digital sideband separation for the Yuan Tseh Lee Array to double the processing bandwidth. The receiver consists of a MMIC HEMT LNA frontend operating at a wavelength of 3 mm, and sub-harmonic mixers that output signals at intermediate frequencies of 2 - 18 GHz. The sideband separation scheme involves an analog 90 degree hybrid followed by two mixers that provide down conversion of the IF signal to a pair of in phase (I) and quadrature (Q) signals in baseband. The I and Q baseband signals are digitized using 5 Giga sample per second analog to digital converters. A second hybrid is digitally implemented using field programmable gate arrays to produce two sidebands, each with a bandwidth of 1.6 GHz. The 2 x 1.6 GHz band can be tuned to cover any 3.2 GHz window within the aforementioned IF range of the array. Sideband rejection ratios (SRRs) above 20 dB can be obtained across the 3.2 GHz bandwidth by equalizing the power and delay between the I and Q baseband signals. Furthermore, SRRs above 30 dB can be achieved when calibration is applied., 8 pages, 12 figures
Published: 2022

3. First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way

Author: null Event Horizon Telescope Collaboration, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Baloković, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Do-Young Byun, John E. Carlstrom, Chiara Ceccobello, Andrew Chael, Chi-kwan Chan, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre Christian, Nicholas S. Conroy, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Vedant Dhruv, Sheperd S. Doeleman, Sean Dougal, Sergio A. Dzib, Ralph P. Eatough, Razieh Emami, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Charles F. Gammie, Roberto García, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Arturo I. Gómez-Ruiz, José L. Gómez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Kari Haworth, Michael H. Hecht, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jiménez-Rosales, Michael D. Johnson, Svetlana Jorstad, Abhishek V. Joshi, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Noemi La Bella, Tod R. Lauer, Daeyoung Lee, Sang-Sung Lee, Po Kin Leung, Aviad Levis, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Ru-Sen Lu, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iván Martí-Vidal, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Daniel Michalik, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Monika Moscibrodzka, Cornelia Müller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Andrew Nadolski, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Ramesh Narayan, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Junghwan Oh, Hiroki Okino, Héctor Olivares, Gisela N. Ortiz-León, Tomoaki Oyama, Feryal Özel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Piétu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Felix M. Pötzl, Ben Prather, Jorge A. Preciado-López, Dimitrios Psaltis, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Angelo Ricarte, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Cañizales, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Argüelles, Miguel Sánchez-Portal, Mahito Sasada, Kaushik Satapathy, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, Kamal Souccar, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Maciek Wielgus, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Qingwen Wu, Paul Yamaguchi, Doosoo Yoon, André Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao, Claudio Agurto, Alexander Allardi, Rodrigo Amestica, Juan Pablo Araneda, Oriel Arriagada, Jennie L. Berghuis, Alessandra Bertarini, Ryan Berthold, Jay Blanchard, Ken Brown, Mauricio Cárdenas, Michael Cantzler, Patricio Caro, Edgar Castillo-Domínguez, Tin Lok Chan, Chih-Cheng Chang, Dominic O. Chang, Shu-Hao Chang, Song-Chu Chang, Chung-Chen Chen, Ryan Chilson, Tim C. Chuter, Miroslaw Ciechanowicz, Edgar Colin-Beltran, Iain M. Coulson, Joseph Crowley, Nathalie Degenaar, Sven Dornbusch, Carlos A. Durán, Wendeline B. Everett, Aaron Faber, Karl Forster, Miriam M. Fuchs, David M. Gale, Gertie Geertsema, Edouard González, Dave Graham, Frédéric Gueth, Nils W. Halverson, Chih-Chiang Han, Kuo-Chang Han, Yutaka Hasegawa, José Luis Hernández-Rebollar, Cristian Herrera, Ruben Herrero-Illana, Stefan Heyminck, Akihiko Hirota, James Hoge, Shelbi R. Hostler Schimpf, Ryan E. Howie, Yau-De Huang, Homin Jiang, Hao Jinchi, David John, Kimihiro Kimura, Thomas Klein, Derek Kubo, John Kuroda, Caleb Kwon, Richard Lacasse, Robert Laing, Erik M. Leitch, Chao-Te Li, Ching-Tang Liu, Kuan-Yu Liu, Lupin C.-C. Lin, Li-Ming Lu, Felipe Mac-Auliffe, Pierre Martin-Cocher, Callie Matulonis, John K. Maute, Hugo Messias, Zheng Meyer-Zhao, Alfredo Montaña, Francisco Montenegro-Montes, William Montgomerie, Marcos Emir Moreno Nolasco, Dirk Muders, Hiroaki Nishioka, Timothy J. Norton, George Nystrom, Hideo Ogawa, Rodrigo Olivares, Peter Oshiro, Juan Pablo Pérez-Beaupuits, Rodrigo Parra, Neil M. Phillips, Michael Poirier, Nicolas Pradel, Richard Qiu, Philippe A. Raffin, Alexandra S. Rahlin, Jorge Ramírez, Sean Ressler, Mark Reynolds, Iván Rodríguez-Montoya, Alejandro F. Saez-Madain, Jorge Santana, Paul Shaw, Leslie E. Shirkey, Kevin M. Silva, William Snow, Don Sousa, T. K. Sridharan, William Stahm, Anthony A. Stark, John Test, Karl Torstensson, Paulina Venegas, Craig Walther, Ta-Shun Wei, Chris White, Gundolf Wieching, Rudy Wijnands, Jan G. A. Wouterloot, Chen-Yu Yu, Wei Yu (于威), Milagros Zeballos, High Energy Astrophys. & Astropart. Phys (API, FNWI), Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Azulay, R., Asada, K., Bach, U., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Baubock, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chan, C. -K., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., Gentaz, O., Georgiev, B., Garcia, R., Goddi, C., Gold, R., Gomez-Ruiz, A. I., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., La Bella, N., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lu, R. -S., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Mus, A., Musoke, G., Myserlis, I., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. N., Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Paraschos, G. F., Park, J., Parsons, H., Patel, N., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Potzl, F. M., Prather, B., Preciado-Lopez, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Romero-Canizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sanchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tilanus, R. P. J., Tiede, P., Titus, M., Torne, P., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yamaguchi, P., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., Agurto, C., Allardi, A., Amestica, R., Araneda, J. P., Arriagada, O., Berghuis, J. L., Bertarini, A., Berthold, R., Blanchard, J., Brown, K., Cardenas, M., Cantzler, M., Caro, P., Castillo-Dominguez, E., Chan, T. L., Chang, C. -C., Chang, D. O., Chang, S. -H., Chang, S. -C., Chen, C. -C., Chilson, R., Chuter, T. C., Ciechanowicz, M., Colin-Beltran, E., Coulson, I. M., Crowley, J., Degenaar, N., Dornbusch, S., Duran, C. A., Everett, W. B., Faber, A., Forster, K., Fuchs, M. M., Gale, D. M., Geertsema, G., Gonzalez, E., Graham, D., Gueth, F., Halverson, N. W., Han, C. -C., Han, K. -C., Hasegawa, Y., Hernandez-Rebollar, J. L., Herrera, C., Herrero-Illana, R., Heyminck, S., Hirota, A., Hoge, J., Hostler Schimpf, S. R., Howie, R. E., Huang, Y. -D., Jiang, H., Jinchi, H., John, D., Kimura, K., Klein, T., Kubo, D., Kuroda, J., Kwon, C., Lacasse, R., Laing, R., Leitch, E. M., Li, C. -T., Liu, C. -T., Liu, K. -Y., Lin, L. C. -C., Lu, L. -M., Mac-Auliffe, F., Martin-Cocher, P., Matulonis, C., Maute, J. K., Messias, H., Meyer-Zhao, Z., Montana, A., Montenegro-Montes, F., Montgomerie, W., Nolasco, M. E. M., Muders, D., Nishioka, H., Norton, T. J., Nystrom, G., Ogawa, H., Olivares, R., Oshiro, P., Perez-Beaupuits, J. P., Parra, R., Phillips, N. M., Poirier, M., Pradel, N., Qiu, R., Raffin, P. A., Rahlin, A. S., Ramirez, J., Ressler, S., Reynolds, M., Rodriguez-Montoya, I., Saez-Madain, A. F., Santana, J., Shaw, P., Shirkey, L. E., Silva, K. M., Snow, W., Sousa, D., Sridharan, T. K., Stahm, W., Stark, A. A., Test, J., Torstensson, K., Venegas, P., Walther, C., Wei, T. -S., White, C., Wieching, G., Wijnands, R., Wouterloot, J. G. A., Yu, C. -Y., Yu, W., Zeballos, M., Akiyama, Kazunori [0000-0002-9475-4254], Alberdi, Antxon [0000-0002-9371-1033], Algaba, Juan Carlos [0000-0001-6993-1696], Anantua, Richard [0000-0003-3457-7660], Asada, Keiichi [0000-0001-6988-8763], Azulay, Rebecca [0000-0002-2200-5393], Bach, Uwe [0000-0002-7722-8412], Baczko, Anne-Kathrin [0000-0003-3090-3975], Baloković, Mislav [0000-0003-0476-6647], Barrett, John [0000-0002-9290-0764], Bauböck, Michi [0000-0002-5518-2812], Benson, Bradford A. [0000-0002-5108-6823], Blackburn, Lindy [0000-0002-9030-642X], Blundell, Raymond [0000-0002-5929-5857], Bouman, Katherine L. [0000-0003-0077-4367], Bower, Geoffrey C. [0000-0003-4056-9982], Boyce, Hope [0000-0002-6530-5783], Brinkerink, Christiaan D. [0000-0002-2322-0749], Brissenden, Roger [0000-0002-2556-0894], Britzen, Silke [0000-0001-9240-6734], Broderick, Avery E. [0000-0002-3351-760X], Broguiere, Dominique [0000-0001-9151-6683], Bronzwaer, Thomas [0000-0003-1151-3971], Bustamante, Sandra [0000-0001-6169-1894], Byun, Do-Young [0000-0003-1157-4109], Carlstrom, John E. [0000-0002-2044-7665], Ceccobello, Chiara [0000-0002-4767-9925], Chael, Andrew [0000-0003-2966-6220], Chan, Chi-kwan [0000-0001-6337-6126], Chatterjee, Koushik [0000-0002-2825-3590], Chatterjee, Shami [0000-0002-2878-1502], Chen, Ming-Tang [0000-0001-6573-3318], Chen, Yongjun [0000-0001-5650-6770], Cheng, Xiaopeng [0000-0003-4407-9868], Cho, Ilje [0000-0001-6083-7521], Christian, Pierre [0000-0001-6820-9941], Conroy, Nicholas S. [0000-0003-2886-2377], Conway, John E. [0000-0003-2448-9181], Cordes, James M. [0000-0002-4049-1882], Crawford, Thomas M. [0000-0001-9000-5013], Crew, Geoffrey B. [0000-0002-2079-3189], Cruz-Osorio, Alejandro [0000-0002-3945-6342], Cui, Yuzhu [0000-0001-6311-4345], Davelaar, Jordy [0000-0002-2685-2434], Laurentis, Mariafelicia De [0000-0002-9945-682X], Deane, Roger [0000-0003-1027-5043], Dempsey, Jessica [0000-0003-1269-9667], Desvignes, Gregory [0000-0003-3922-4055], Dexter, Jason [0000-0003-3903-0373], Dhruv, Vedant [0000-0001-6765-877X], Doeleman, Sheperd S. [0000-0002-9031-0904], Dougal, Sean [0000-0002-3769-1314], Dzib, Sergio A. [0000-0001-6010-6200], Eatough, Ralph P. [0000-0001-6196-4135], Emami, Razieh [0000-0002-2791-5011], Falcke, Heino [0000-0002-2526-6724], Farah, Joseph [0000-0003-4914-5625], Fish, Vincent L. [0000-0002-7128-9345], Fomalont, Ed [0000-0002-9036-2747], Ford, H. Alyson [0000-0002-9797-0972], Fraga-Encinas, Raquel [0000-0002-5222-1361], Friberg, Per [0000-0002-8010-8454], Fromm, Christian M. [0000-0002-1827-1656], Fuentes, Antonio [0000-0002-8773-4933], Galison, Peter [0000-0002-6429-3872], Gammie, Charles F. [0000-0001-7451-8935], García, Roberto [0000-0002-6584-7443], Gentaz, Olivier [0000-0002-0115-4605], Georgiev, Boris [0000-0002-3586-6424], Goddi, Ciriaco [0000-0002-2542-7743], Gold, Roman [0000-0003-2492-1966], Gómez-Ruiz, Arturo I. [0000-0001-9395-1670], Gómez, José L. [0000-0003-4190-7613], Gu, Minfeng [0000-0002-4455-6946], Gurwell, Mark [0000-0003-0685-3621], Hada, Kazuhiro [0000-0001-6906-772X], Haggard, Daryl [0000-0001-6803-2138], Hecht, Michael H. [0000-0002-4114-4583], Hesper, Ronald [0000-0003-1918-6098], Heumann, Dirk [0000-0002-7671-0047], Ho, Luis C. [0000-0001-6947-5846], Ho, Paul [0000-0002-3412-4306], Honma, Mareki [0000-0003-4058-9000], Huang, Chih-Wei L. [0000-0001-5641-3953], Huang, Lei [0000-0002-1923-227X], Ikeda, Shiro [0000-0002-2462-1448], Impellizzeri, C. M. Violette [0000-0002-3443-2472], Inoue, Makoto [0000-0001-5037-3989], Issaoun, Sara [0000-0002-5297-921X], James, David J. [0000-0001-5160-4486], Jannuzi, Buell T. [0000-0002-1578-6582], Janssen, Michael [0000-0001-8685-6544], Jeter, Britton [0000-0003-2847-1712], Jiang, Wu [0000-0001-7369-3539], Jiménez-Rosales, Alejandra [0000-0002-2662-3754], Johnson, Michael D. [0000-0002-4120-3029], Jorstad, Svetlana [0000-0001-6158-1708], Joshi, Abhishek V. [0000-0002-2514-5965], Jung, Taehyun [0000-0001-7003-8643], Karami, Mansour [0000-0001-7387-9333], Karuppusamy, Ramesh [0000-0002-5307-2919], Kawashima, Tomohisa [0000-0001-8527-0496], Keating, Garrett K. [0000-0002-3490-146X], Kettenis, Mark [0000-0002-6156-5617], Kim, Dong-Jin [0000-0002-7038-2118], Kim, Jae-Young [0000-0001-8229-7183], Kim, Jongsoo [0000-0002-1229-0426], Kim, Junhan [0000-0002-4274-9373], Kino, Motoki [0000-0002-2709-7338], Koay, Jun Yi [0000-0002-7029-6658], Kocherlakota, Prashant [0000-0001-7386-7439], Koch, Patrick M. [0000-0003-2777-5861], Koyama, Shoko [0000-0002-3723-3372], Kramer, Carsten [0000-0002-4908-4925], Kramer, Michael [0000-0002-4175-2271], Krichbaum, Thomas P. [0000-0002-4892-9586], Kuo, Cheng-Yu [0000-0001-6211-5581], Bella, Noemi La [0000-0002-8116-9427], Lauer, Tod R. [0000-0003-3234-7247], Lee, Daeyoung [0000-0002-3350-5588], Lee, Sang-Sung [0000-0002-6269-594X], Leung, Po Kin [0000-0002-8802-8256], Levis, Aviad [0000-0001-7307-632X], Li, Zhiyuan [0000-0003-0355-6437], Lico, Rocco [0000-0001-7361-2460], Lindahl, Greg [0000-0002-6100-4772], Lindqvist, Michael [0000-0002-3669-0715], Lisakov, Mikhail [0000-0001-6088-3819], Liu, Jun [0000-0002-7615-7499], Liu, Kuo [0000-0002-2953-7376], Liuzzo, Elisabetta [0000-0003-0995-5201], Lo, Wen-Ping [0000-0003-1869-2503], Lobanov, Andrei P. [0000-0003-1622-1484], Loinard, Laurent [0000-0002-5635-3345], Lonsdale, Colin J. [0000-0003-4062-4654], Lu, Ru-Sen [0000-0002-7692-7967], Mao, Jirong [0000-0002-7077-7195], Marchili, Nicola [0000-0002-5523-7588], Markoff, Sera [0000-0001-9564-0876], Marrone, Daniel P. [0000-0002-2367-1080], Marscher, Alan P. [0000-0001-7396-3332], Martí-Vidal, Iván [0000-0003-3708-9611], Matsushita, Satoki [0000-0002-2127-7880], Matthews, Lynn D. [0000-0002-3728-8082], Medeiros, Lia [0000-0003-2342-6728], Menten, Karl M. [0000-0001-6459-0669], Michalik, Daniel [0000-0002-7618-6556], Mizuno, Izumi [0000-0002-7210-6264], Mizuno, Yosuke [0000-0002-8131-6730], Moran, James M. [0000-0002-3882-4414], Moriyama, Kotaro [0000-0003-1364-3761], Moscibrodzka, Monika [0000-0002-4661-6332], Müller, Cornelia [0000-0002-2739-2994], Mus, Alejandro [0000-0003-0329-6874], Musoke, Gibwa [0000-0003-1984-189X], Myserlis, Ioannis [0000-0003-3025-9497], Nadolski, Andrew [0000-0001-9479-9957], Nagai, Hiroshi [0000-0003-0292-3645], Nagar, Neil M. [0000-0001-6920-662X], Nakamura, Masanori [0000-0001-6081-2420], Narayan, Ramesh [0000-0002-1919-2730], Narayanan, Gopal [0000-0002-4723-6569], Natarajan, Iniyan [0000-0001-8242-4373], Neilsen, Joey [0000-0002-8247-786X], Neri, Roberto [0000-0002-7176-4046], Ni, Chunchong [0000-0003-1361-5699], Noutsos, Aristeidis [0000-0002-4151-3860], Nowak, Michael A. [0000-0001-6923-1315], Oh, Junghwan [0000-0002-4991-9638], Okino, Hiroki [0000-0003-3779-2016], Olivares, Héctor [0000-0001-6833-7580], Ortiz-León, Gisela N. [0000-0002-2863-676X], Oyama, Tomoaki [0000-0003-4046-2923], Özel, Feryal [0000-0003-4413-1523], Palumbo, Daniel C. M. [0000-0002-7179-3816], Paraschos, Georgios Filippos [0000-0001-6757-3098], Park, Jongho [0000-0001-6558-9053], Parsons, Harriet [0000-0002-6327-3423], Patel, Nimesh [0000-0002-6021-9421], Pen, Ue-Li [0000-0003-2155-9578], Pesce, Dominic W. [0000-0002-5278-9221], Plambeck, Richard [0000-0001-6765-9609], Porth, Oliver [0000-0002-4584-2557], Pötzl, Felix M. [0000-0002-6579-8311], Prather, Ben [0000-0002-0393-7734], Preciado-López, Jorge A. [0000-0002-4146-0113], Psaltis, Dimitrios [0000-0003-1035-3240], Pu, Hung-Yi [0000-0001-9270-8812], Ramakrishnan, Venkatessh [0000-0002-9248-086X], Rao, Ramprasad [0000-0002-1407-7944], Rawlings, Mark G. [0000-0002-6529-202X], Raymond, Alexander W. [0000-0002-5779-4767], Rezzolla, Luciano [0000-0002-1330-7103], Ricarte, Angelo [0000-0001-5287-0452], Ripperda, Bart [0000-0002-7301-3908], Roelofs, Freek [0000-0001-5461-3687], Rogers, Alan [0000-0003-1941-7458], Ros, Eduardo [0000-0001-9503-4892], Romero-Cañizales, Cristina [0000-0001-6301-9073], Roshanineshat, Arash [0000-0002-8280-9238], Roy, Alan L. [0000-0002-1931-0135], Ruiz, Ignacio [0000-0002-0965-5463], Ruszczyk, Chet [0000-0001-7278-9707], Rygl, Kazi L. J. 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[0000-0001-6952-2147], Wu, Qingwen [0000-0003-4773-4987], Yamaguchi, Paul [0000-0002-6017-8199], Yoon, Doosoo [0000-0001-8694-8166], Young, André [0000-0003-0000-2682], Young, Ken [0000-0002-3666-4920], Younsi, Ziri [0000-0001-9283-1191], Yuan, Feng [0000-0003-3564-6437], Yuan, Ye-Fei [0000-0002-7330-4756], Zensus, J. Anton [0000-0001-7470-3321], Zhang, Shuo [0000-0002-2967-790X], Zhao, Guang-Yao [0000-0002-4417-1659], Zhao, Shan-Shan [0000-0002-9774-3606], Berghuis, Jennie L. [0000-0003-2287-158X], Blanchard, Jay [0000-0002-2756-395X], Chan, Tin Lok [0000-0001-9197-932X], Coulson, Iain M. [0000-0002-7316-4626], Degenaar, Nathalie [0000-0002-0092-3548], Durán, Carlos A. [0000-0001-7622-3890], Everett, Wendeline B. [0000-0002-5370-6651], Forster, Karl [0000-0001-5800-5531], Halverson, Nils W. [0000-0003-2606-9340], Herrero-Illana, Ruben [0000-0002-7758-8717], Hirota, Akihiko [0000-0002-0465-5421], Howie, Ryan E. [0000-0002-5451-3624], Kwon, Caleb [0000-0001-9006-7345], Laing, Robert [0000-0001-6786-3087], Leitch, Erik M. [0000-0001-8553-9336], Lin, Lupin C.-C. [0000-0003-4083-9567], Maute, John K. [0000-0002-5744-4249], Messias, Hugo [0000-0002-2985-7994], Montenegro-Montes, Francisco [0000-0002-7430-3771], Muders, Dirk [0000-0002-2315-2571], Pérez-Beaupuits, Juan Pablo [0000-0003-3536-2274], Poirier, Michael [0000-0001-6641-0959], Qiu, Richard [0000-0003-3462-0817], Rahlin, Alexandra S. [0000-0003-3953-1776], Ressler, Sean [0000-0003-0220-5723], Reynolds, Mark [0000-0003-1621-9392], Saez-Madain, Alejandro F. [0000-0002-0804-3414], Sousa, Don [0000-0002-2625-2607], Stark, Anthony A. [0000-0002-2718-9996], White, Chris [0000-0001-7448-4253], Wijnands, Rudy [0000-0002-3516-2152], Wouterloot, Jan G. A. [0000-0002-4694-6905], Yu (于威), Wei [0000-0002-5168-6052], Apollo - University of Cambridge Repository, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Science and Technology Facilities Council (UK), Astronomy, Metsähovi Radio Observatory, Department of Electronics and Nanoengineering, Science Support Office, Aalto-yliopisto, and Aalto University
Subjects: Black holes, F520, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, F521, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 5109 Space Sciences, Heterodyne interferometry, Galactic center, General Relativity and Quantum Cosmology, Space and Planetary Science, 5101 Astronomical Sciences, Kerr black holes, Rotating black holes, 51 Physical Sciences, Astrophysics::Galaxy Astrophysics, Mathematics
Abstract: This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Full list of authors: Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Bach, Uwe; Baczko, Anne-Kathrin; Ball, David; Balokovic, Mislav; Barrett, John; Baubock, Michi; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Bustamante, Sandra; Byun, Do-Young; Carlstrom, John E.; Ceccobello, Chiara; Chael, Andrew; Chan, Chi-kwan; Chatterjee, Koushik; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cheng, Xiaopeng; Cho, Ilje; Christian, Pierre; Conroy, Nicholas S.; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Dhruv, Vedant; Doeleman, Sheperd S.; Dougal, Sean; Dzib, Sergio A.; Eatough, Ralph P.; Emami, Razieh; 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.; Garcia, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gold, Roman; Gomez-Ruiz, Arturo, I; Gomez, Jose L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Haworth, Kari; Hecht, Michael H.; Hesper, Ronald; Heumann, Dirk; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Impellizzeri, C. M. Violette; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Joshi, Abhishek, V; 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; Kocherlakota, Prashant; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; La Bella, Noemi; Lauer, Tod R.; Lee, Daeyoung; Lee, Sang-Sung; Leung, Po Kin; Levis, Aviad; Li, Zhiyuan; Lico, Rocco; Lindahl, Greg; Lindqvist, Michael; Lisakov, Mikhail; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin J.; Lu, Ru-Sen; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Marti-Vidal, Ivan; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Michalik, Daniel; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Muller, Cornelia; Mus, Alejandro; Musoke, Gibwa; Myserlis, Ioannis; Nadolski, Andrew; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Fuentes, Santiago Navarro; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Oh, Junghwan; Okino, Hiroki; Olivares, Hector; Ortiz-Leon, Gisela N.; Oyama, Tomoaki; Palumbo, Daniel C. M.; Paraschos, Georgios Filippos; Park, Jongho; Parsons, Harriet; Patel, Nimesh; Pen, Ue-Li; Pesce, Dominic W.; Pietu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Potzl, Felix M.; Prather, Ben; Preciado-Lopez, Jorge A.; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ricarte, Angelo; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Romero-Canizales, Cristina; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruiz, Ignacio; Ruszczyk, Chet; Rygl, Kazi L. J.; Sanchez, Salvador; Sanchez-Arguelles, David; Sanchez-Portal, Miguel; Sasada, Mahito; Satapathy, Kaushik; Savolainen, Tuomas; Schloerb, F. Peter; Schonfeld, Jonathan; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Souccar, Kamal; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; Turk, Matthew; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Vos, Jesse; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wiik, Kaj; Witzel, Gunther; Wondrak, Michael F.; Wong, George N.; Wu, Qingwen; Yamaguchi, Paul; Yoon, Doosoo; Young, Andre; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhang, Shuo; Zhao, Guang-Yao; Zhao, Shan-Shan; Ozel, Feryal; Agurto, Claudio; Allardi, Alexander; Amestica, Rodrigo; Araneda, Juan Pablo; Arriagada, Oriel; Berghuis, Jennie L.; Bertarini, Alessandra; Berthold, Ryan; Blanchard, Jay; Brown, Ken; Cardenas, Mauricio; Cantzler, Michael; Caro, Patricio; Castillo-Dominguez, Edgar; Chan, Tin Lok; Chang, Chih-Cheng; Chang, Dominic O.; Chang, Shu-Hao; Chang, Song-Chu; Chen, Chung-Chen; Chilson, Ryan; Chuter, Tim C.; Ciechanowicz, Miroslaw; Colin-Beltran, Edgar; Coulson, Iain M.; Crowley, Joseph; Degenaar, Nathalie; Dornbusch, Sven; Duran, Carlos A.; Everett, Wendeline B.; Faber, Aaron; Forster, Karl; Fuchs, Miriam M.; Gale, David M.; Geertsema, Gertie; Gonzalez, Edouard; Graham, Dave; Gueth, Frederic; Halverson, Nils W.; Han, Chih-Chiang; Han, Kuo-Chang; Hasegawa, Yutaka; Hernandez-Rebollar, Jose Luis; Herrera, Cristian; Herrero-Illana, Ruben; Heyminck, Stefan; Hirota, Akihiko; Hoge, James; Schimpf, Shelbi R. Hostler; Howie, Ryan E.; Huang, Yau-De; Jiang, Homin; Jinchi, Hao; John, David; Kimura, Kimihiro; Klein, Thomas; Kubo, Derek; Kuroda, John; Kwon, Caleb; Lacasse, Richard; Laing, Robert; Leitch, Erik M.; Li, Chao-Te; Liu, Ching-Tang; Liu, Kuan-Yu; Lin, Lupin C-C; Lu, Li-Ming; Mac-Auliffe, Felipe; Martin-Cocher, Pierre; Matulonis, Callie; Maute, John K.; Messias, Hugo; Meyer-Zhao, Zheng; Montana, Alfredo; Montenegro-Montes, Francisco; Montgomerie, William; Nolasco, Marcos Emir Moreno; Muders, Dirk; Nishioka, Hiroaki; Norton, Timothy J.; Nystrom, George; Ogawa, Hideo; Olivares, Rodrigo; Oshiro, Peter; Perez-Beaupuits, Juan Pablo; Parra, Rodrigo; Phillips, Neil M.; Poirier, Michael; Pradel, Nicolas; Qiu, Richard; Raffin, Philippe A.; Rahlin, Alexandra S.; Ramirez, Jorge; Ressler, Sean; Reynolds, Mark; Rodriguez-Montoya, Ivan; Saez-Madain, Alejandro F.; Santana, Jorge; Shaw, Paul; Shirkey, Leslie E., Jr.; Silva, Kevin M.; Snow, William; Sousa, Don; Sridharan, T. K.; Stahm, William; Stark, Anthony A.; Test, John; Torstensson, Karl; Venegas, Paulina; Walther, Craig; Wei, Ta-Shun; White, Chris; Wieching, Gundolf; Wijnands, Rudy; Wouterloot, Jan G. A.; Yu, Chen-Yu; Yu, Wei; Zeballos, Milagros; Event Horizon Telescope Collaboration., We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A*), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric array of eight telescopes operating at a wavelength of λ = 1.3 mm. The EHT data resolve a compact emission region with intrahour variability. A variety of imaging and modeling analyses all support an image that is dominated by a bright, thick ring with a diameter of 51.8 ± 2.3 μas (68% credible interval). The ring has modest azimuthal brightness asymmetry and a comparatively dim interior. Using a large suite of numerical simulations, we demonstrate that the EHT images of Sgr A* are consistent with the expected appearance of a Kerr black hole with mass ∼4 × 106 M⊙, which is inferred to exist at this location based on previous infrared observations of individual stellar orbits, as well as maser proper-motion studies. Our model comparisons disfavor scenarios where the black hole is viewed at high inclination (i > 50°), as well as nonspinning black holes and those with retrograde accretion disks. Our results provide direct evidence for the presence of a supermassive black hole at the center of the Milky Way, and for the first time we connect the predictions from dynamical measurements of stellar orbits on scales of 103–105 gravitational radii to event-horizon-scale images and variability. Furthermore, a comparison with the EHT results for the supermassive black hole M87* shows consistency with the predictions of general relativity spanning over three orders of magnitude in central mass. © 2022. The Author(s). Published by the American Astronomical Society., The Event Horizon Telescope Collaboration thanks the following organizations and programs: the Academia Sinica; the Academy of Finland (projects 274477, 284495, 312496, 315721); the Agencia Nacional de Investigación y Desarrollo (ANID), Chile via NCN19_058 (TITANs) and Fondecyt 1221421, the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA and the astronomy institutes of the University of Amsterdam, Leiden University and Radboud University; the ALMA North America Development Fund; the Black Hole Initiative, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation (although the opinions expressed in this work are those of the author(s) and do not necessarily reflect the views of these Foundations); Chandra DD7-18089X and TM6-17006X; the China Scholarship Council; China Postdoctoral Science Foundation fellowship (2020M671266); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, 263356); the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (DGAPA-UNAM, projects IN112417 and IN112820); the Dutch Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and grant OCENW.KLEIN.113; the Dutch National Supercomputers, Cartesius and Snellius (NWO Grant 2021.013); the EACOA Fellowship awarded by the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, Center for Astronomical Mega-Science, Chinese Academy of Sciences, and the Korea Astronomy and Space Science Institute; the European Research Council (ERC) Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the European Union Horizon 2020 research and innovation programme under grant agreements RadioNet (No 730562) and M2FINDERS (No 101018682); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the European Research Council for advanced grant "JETSET: Launching, propagation and emission of relativistic jets from binary mergers and across mass scales" (Grant No. 884631); the Institute for Advanced Study; the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; DFG research grant "Jet physics on horizon scales and beyond" (Grant No. FR 4069/2-1); Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships, research at the Flatiron Institute is supported by the Simons Foundation; the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT; grant JPMXP1020200109); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Joint Institute for Computational Fundamental Science, Japan; the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJSSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP21H01137, JP18H03721, JP18K13594, 18K03709, JP19K14761, 18H01245, 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, and 110-2923-M-001-001); the Ministry of Education (MoE) of Taiwan Yushan Young Scholar Program; the Physics Division, National Center for Theoretical Sciences of Taiwan; the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645); NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555; the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2017YFA0402703, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1440254, AST-1555365, AST-1614868, AST-1615796, AST-1715061, AST-1716327, AST-1716536, OISE-1743747, AST-1816420, AST-1935980, AST-2034306); NSF Astronomy and Astrophysics Postdoctoral Fellowship (AST-1903847); the Natural Science Foundation of China (grants 11650110427, 10625314, 11721303, 11725312, 11873028, 11933007, 11991052, 11991053, 12192220, 12192223); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, the Korea Research Fellowship Program: NRF-2015H1D3A1066561, Brain Pool Program: 2019H1D3A1A01102564, Basic Research Support Grant 2019R1F1A1059721, 2021R1A6A3A01086420, 2022R1C1C1005255); Netherlands Research School for Astronomy (NOVA) Virtual Institute of Accretion (VIA) postdoctoral fellowships; Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Spanish Ministerio de Ciencia e Innovación (grants PGC2018-098915-B-C21, AYA2016-80889-P, PID2019-108995GB-C21, PID2020-117404GB-C21); the University of Pretoria for financial aid in the provision of the new Cluster Server nodes and SuperMicro (USA) for a SEEDING GRANT approved towards these nodes in 2020; the Shanghai Pilot Program for Basic Research, Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2021-013); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017- 0709); the Spinoza Prize SPI 78-409; the South African Research Chairs Initiative, through the South African Radio Astronomy Observatory (SARAO, grant ID 77948), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Innovation (DSI) of South Africa; the Toray Science Foundation; Swedish Research Council (VR); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001); and the YCAA Prize Postdoctoral Fellowship. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key Research and Development Program (No. 2017YFA0402700) of China and Natural Science Foundation of China grant 11873028. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrófisica, Óptica, y Electrónica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30-m telescope on Pico Veleta, Spain is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck-Gesellschaft, Germany) and IGN (Instituto Geográfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. Support for SPT participation in the EHT is provided by the National Science Foundation through award OPP-1852617 to the University of Chicago. Partial support is also provided by the Kavli Institute of Cosmological Physics at the University of Chicago. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. This research is part of the Frontera computing project at the Texas Advanced Computing Center through the Frontera Large-Scale Community Partnerships allocation AST20023. Frontera is made possible by National Science Foundation award OAC-1818253. This research was carried out using resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy Office of Science. Additional work used ABACUS2.0, which is part of the eScience center at Southern Denmark University. Simulations were also performed on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, on the HazelHen cluster at the HLRS in Stuttgart, and on the Pi2.0 and Siyuan Mark-I at Shanghai Jiao Tong University. The computer resources of the Finnish IT Center for Science (CSC) and the Finnish Computing Competence Infrastructure (FCCI) project are acknowledged. This research was enabled in part by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca) and Compute Canada (http://www.computecanada.ca).
Published: 2022

4. Commissioning of Nāmakanui on the JCMT

Author: David S. Berry, Kuo-Chieh Fu, Dan Bintley, P. L. Smith, Kevin Silva, Izumi Mizuno, Mailani Neil, Ryan Berthold, Ranjani Srinivasan, Graham S. Bell, Chao-Ching Wang, Derek Kubo, Per Friberg, Sarah Graves, Xue-Jian Jiang, William Stahm, Tashun Wei, Shaoliang Li, Alexandra J. Tetarenko, Ya-Che Shih, Alyssa Clark, Chih-Chiang Han, Mark G. Rawlings, Maren Purves, Sung-Po Hsu, Vernon DeMattos, John Kuroda, Callie Matulonis, Pablo Torne, Jamie Cookson, Harriet Parsons, Ed Sison, Steve Mairs, Craig Walther, Paul T. P. Ho, Jessica T. Dempsey, Miriam Fuchs, Ming-Tang Chen, Alexis Acohido, Neal Oliveira, Jason Fleck, and Yau-De Huang
Subjects: Physics, Heterodyne, Very-long-baseline interferometry, FOS: Physical sciences, Astronomy, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract: Namakanui is an instrument containing three inserts in an ALMA type Dewar. The three inserts are Alaihi, Uu and Aweoweo operating around 86, 230 and 345GHz. The receiver is being commissioned on the JCMT. It will be used for both Single dish and VLBI observations. We will present commissioning results and the system., 19 pages, 16 figures, Proceedings of SPIE
Published: 2020
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5. Improving observatory efficiency: noise limited observing at the JCMT

Author: Maren Purves, John Kuroda, Graham S. Bell, Ryan Berthold, Jessica T. Dempsey, Shaoliang Li, Sarah Graves, Dan Bintley, Steven Mairs, Izumi Mizuno, Per Friberg, Harriet Parsons, Mark G. Rawlings, and Craig Walther
Subjects: Computer science, business.industry, Real-time computing, Astrophysics::Instrumentation and Methods for Astrophysics, Process (computing), Elevation, Pipeline (software), law.invention, Telescope, Noise, Software, Observatory, law, business, Queue
Abstract: Most telescope proposal science cases are governed by the need to achieve a given SNR (Signal-to-noise ratio). However, traditionally telescopes award applicants a certain number of hours rather than an SNR or noise. Noise calculators cannot solve this problem entirely, due to variations in weather, elevation and instrument performance when an observation is actually carried out. The JCMT is currently shifting towards awarding users (when appropriate) a given RMS towards their source/s instead of a time spent observing, initially for our new 230 GHz instrument Ū ū. The JCMT already had many necessary parts of this process in place (noise calculators, a robust ‘live’ pipeline, and an extremely flexible queue based system). This presentation describes our efforts to start implementing this process for our users, discusses the necessary systems and software required, and describes the lessons applicable for other observatories.
Published: 2020
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6. Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution

Author: Robert Freund, N. W. Halverson, Benjamin R. Ryan, Paul Shaw, André Young, Andreas Eckart, A. Montaña, Michael Titus, Chen Yu Yu, Gertie Geertsema, Gao Feng, Ronald Grosslein, Ranjani Srinivasan, David Ball, Pablo Torne, Roberto Garcia, Hiroki Okino, Kotaro Moriyama, Chris Eckert, Lupin C.C. Lin, Geoffrey B. Crew, Vernon Fath, Freek Roelofs, David Sánchez-Arguelles, Luciano Rezzolla, Makoto Inoue, Michael Bremer, Jongsoo Kim, James Hoge, Michael Janssen, David M. Gale, Mel Rose, Jason Dexter, Do-Young Byun, J. G. A. Wouterloot, Rubén Herrero-Illana, Daniel C. M. Palumbo, Ta Shun Wei, Ching Tang Liu, Bradford Benson, Jadyn Anczarski, Patrick M. Koch, Ken Young, Jae-Young Kim, Minfeng Gu, Mislav Baloković, Mariafelicia De Laurentis, Laurent Loinard, A. Jiménez-Rosales, Tomohisa Kawashima, Nicolas Pradel, Heino Falcke, Olivier Gentaz, Dirk Muders, Shami Chatterjee, Britton Jeter, Rocco Lico, Craig Walther, David J. James, Homin Jiang, Michael H. Hecht, Gopal Narayanan, Qingwen Wu, Pierre Martin-Cocher, Michael A. Nowak, Alexander W. Raymond, Gregory Desvignes, Anne Kathrin Baczko, Chet Ruszczyk, Yutaka Hasegawa, Chao-Te Li, M. C. H. Wright, Andrew Nadolski, Alan P. Marscher, Christopher Beaudoin, Harriet Parsons, Peñalver Juan, Karl M. Menten, Silke Britzen, Frédéric Gueth, Shu Hao Chang, Andrew Chael, Daryl Haggard, Rodrigo Córdova Rosado, Ru-Sen Lu, Mansour Karami, José L. Gómez, Sang-Sung Lee, Tirupati K. Sridharan, Karl Friedrich Schuster, Ronald Hesper, Richard L. Plambeck, Iain Coulson, Jason SooHoo, Aristeidis Noutsos, Svetlana G. Jorstad, Li Ming Lu, James M. Cordes, David H. Hughes, Jonathan Weintroub, Chih-Wei Locutus Huang, Katherine L. Bouman, Roger J. Cappallo, Lijing Shao, Christiaan D. Brinkerink, John Kuroda, Ramesh Karuppusamy, Iniyan Natarajan, Jessica Dempsey, George Nystrom, John E. Carlstrom, Sera Markoff, Mark Kettenis, Neal R. Erickson, Jason W. Henning, R. Laing, Huang Lei, Kevin A. Dudevoir, Ilje Cho, William Stahm, Juan-Carlos Algaba, Junhan Kim, Hotaka Shiokawa, Martin P. McColl, James M. Moran, Chi-kwan Chan, Timothy C. Chuter, Thomas W. Folkers, Yi Chen, Christopher Greer, Lia Medeiros, C. Y. Kuo, Kuo Chang Han, Shoko Koyama, William Snow, Rurik A. Primiani, Sjoerd T. Timmer, F. Peter Schloerb, Stephen R. McWhirter, Fumie Tazaki, Norbert Wex, Ming-Tang Chen, Nimesh A. Patel, Aaron Faber, Mark Derome, Kazunori Akiyama, W. B. Everett, Hiroshi Nagai, Andrei Lobanov, Ignacio Ruiz, Pierre Christian, N. Phillips, David C. Forbes, Don Sousa, Michael Lindqvist, Christopher Risacher, Wen Ping Lo, Geoffrey C. Bower, Bart Ripperda, Dominique Broguiere, Maciek Wielgus, Antony A. Stark, Raquel Fraga-Encinas, Hiroaki Nishioka, Philippe Raffin, Hugo Messias, Feryal Özel, Jun Yi Koay, Buell T. Jannuzi, Sandra Bustamente, Roberto Neri, Jinchi Hao, Ye-Fei Yuan, Garrett K. Keating, Lynn D. Matthews, Avery E. Broderick, Mark G. Rawlings, Ciriaco Goddi, Tod R. Lauer, Kamal Souccar, Alan L. Roy, S. Navarro, Luis C. Ho, Timothy Norton, Roger Brissenden, Doosoo Yoon, Jongho Park, Richard Lacasse, Paul T. P. Ho, Derek Ward-Thompson, Atish Kamble, Akihiko Hirota, S. Sánchez, D. A. Graham, Vincent Piétu, Kyle D. Massingill, M. Zeballos, Mahito Sasada, Hideo Ogawa, Ziri Younsi, Chih Cheng Chang, Alejandro F. Sáez-Madain, Christian M. Fromm, Ramesh Narayan, Shuichiro Tsuda, Ryan Berthold, Gibwa Musoke, Laura Vertatschitsch, Masanori Nakamura, Remo P. J. Tilanus, Cornelia Müller, Kimihiro Kimura, Roman Gold, Venkatessh Ramakrishnan, Yuzhu Cui, Frederick K. Baganoff, Alan R. Whitney, Aleksandar Popstefanija, Helge Rottmann, Yuan Feng, Ralph Eatough, Tuomas Savolainen, Neil M. Nagar, Alexander Allardi, M. Mora-Klein, Thomas Bronzwaer, Mark Gurwell, Bong Won Sohn, Ivan Marti-Vidal, Chih Chiang Han, Hung Yi Pu, Yan-Rong Li, Shan Shan Zhao, Song Chu Chang, Zhi-Qiang Shen, John F. C. Wardle, Carsten Kramer, Koushik Chatterjee, Wagner Jan, Tomoaki Oyama, Ray Blundell, Motoki Kino, Alan E. E. Rogers, Rebecca Azulay, Jordy Davelaar, Tyler Trent, Satoki Matsushita, Kazi L.J. Rygl, Shuo Zhang, John E. Barrett, Peter Oshiro, Ryan Chilson, Jorge A. Preciado-López, Daniel Michalik, Peter Galison, Uwe Bach, Ilse van Bemmel, Pim Schellart, Michael D. Johnson, Jiang Wu, J. Anton Zensus, S. A. Dzib, Arturo I. Gómez-Ruiz, Meyer Zhao Zheng, David John, Dimitrios Psaltis, Daniel P. Marrone, M. Poirier, Shiro Ikeda, Ralph G. Marson, A. Hernandez-Gomez, Sven Dornbusch, George Reiland, Mareki Honma, J. Blanchard, Ed Fomalont, Taehyun Jung, Izumi Mizuno, Monika Moscibrodzka, Vincent L. Fish, Matthew R. Dexter, Paul Tiede, Rodrigo Amestica, Nicholas R. MacDonald, Gisela N. Ortiz-León, Colin J. Lonsdale, Callie Matulonis, Charles F. Gammie, Per Friberg, Boris Georgiev, W. Boland, Ramprasad Rao, Guang-Yao Zhao, Joseph R. Farah, Zhiyuan Li, Hector Olivares, Sara Issaoun, Elisabetta Liuzzo, C. M. Violette Impellizzeri, Michael Kramer, Oliver Porth, Thomas P. Krichbaum, Dominic W. Pesce, Daniel R. van Rossum, David R. Smith, Robert Wharton, Kuan Yu Liu, David P. Woody, Arash Roshanineshat, Sheperd S. Doeleman, Chung Chen Chen, Ziyan Zhu, Ue-Li Pen, Yosuke Mizuno, Prather Ben, Sascha Trippe, Walter Alef, Liu Kuo, Alexandra S. Rahlin, William Montgomerie, George N. Wong, Jirong Mao, Kazuhiro Hada, Efthalia Traianou, John Conway, Remi Sassella, Eduardo Ros, Kevin M. Silva, Derek Kubo, E. Castillo-Domínguez, Huib Jan van Langevelde, Keiichi Asada, Des Small, Joseph Neilsen, Chi H. Nguyen, Chunchong Ni, Yusuke Kono, Ryan Keisler, Paul Yamaguchi, Lindy Blackburn, Erik M. Leitch, Roger Deane, Lucy M. Ziurys, K. T. Story, Joseph Crowley, Nathan Whitehorn, Stefan Heyminck, Kenji Toma, Antxon Alberdi, Yau De Huang, Dan Bintley, Y Kim, J., Krichbaum, T. P., Broderick, A. E., Wielgus, M., Blackburn, L., Gomez, J. -L., Johnson, M. D., Bouman, K. L., Chael, A., Akiyama, K., Jorstad, S., Marscher, A. P., Issaoun, S., Janssen, M., Chan, C. -K., Savolainen, T., Pesce, D. W., Ozel, F., De Laurentis, M., Deane, R., Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Instituto de RadioAstronomía Milimétrica (IRAM), Event Horizon Telescope, Ministerio de Economía y Competitividad (España), European Commission, National Aeronautics and Space Administration (US), Max Planck Institute for Radio Astronomy, Perimeter Institute for Theoretical Physics, Harvard University, CSIC, Princeton University, Boston University, Radboud University Nijmegen, University of Arizona, Anne Lähteenmäki Group, Academia Sinica - Institute of Astronomy and Astrophysics, Massachusetts Institute of Technology, East Asian Observatory, Nederlandse Onderzoekschool voor Astronomie, Academia Sinica, Institut de Radio Astronomie Millimétrique, Korea Astronomy and Space Science Institute, University of Chicago, Cornell University, University of Amsterdam, CAS - Shanghai Astronomical Observatory, Chalmers University of Technology, National Astronomical Observatory of Japan, University of Naples Federico II, University of Pretoria, University of Colorado Boulder, National Radio Astronomy Observatory, Goethe University Frankfurt, University of Illinois at Urbana-Champaign, University of Waterloo, Instituto Nacional de Astrofisica Optica y Electronica, University of Groningen, Peking University, Max Planck Institute for Extraterrestrial Physics, Joint Institute for VLBI in Europe, California Institute of Technology, National Sun Yat-sen University, National Optical Astronomy Observatory, CAS - Institute of High Energy Physics, Nanjing University, INAF Istituto di Radioastronomia, Instituto de Radioastronomía y Astrofísica, CAS - National Astronomical Observatories, Universidad de Valencia, Universidad de Concepción, University of Massachusetts, Rhodes University, University of California Berkeley, Los Alamos National Laboratory, IRAM, Tohoku University, Seoul National University, Brandeis University, University of Central Lancashire, Huazhong University of Science and Technology, University of Science and Technology of China, University of Vermont, Villanova University, United States Department of Energy, Western University, Royal Netherlands Meteorological Institute, McGill University, Osaka Prefecture University, European Southern Observatory Santiago, University of Manchester, National Radio Astronomy Observatory Socorro, Rochester Institute of Technology, Washington University St. Louis, Systems and Technology Research, Georgia Institute of Technology, Stanford University, University of California Los Angeles, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, Astronomy, High Energy Astrophys. & Astropart. Phys (API, FNWI), and Gravitation and Astroparticle Physics Amsterdam
Subjects: ACTIVE GALACTIC NUCLEI, Brightness, Active galactic nucleus, active [Galaxies], Astrophysics::High Energy Astrophysical Phenomena, Astronomy, galaxies: active, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Submillimeter Array, FLOWS, SCALE CIRCULAR-POLARIZATION, 0103 physical sciences, Very-long-baseline interferometry, Blazar, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Event Horizon Telescope, [PHYS]Physics [physics], Jet (fluid), 010308 nuclear & particles physics, Astronomy and Astrophysics, FLARE, galaxies: jets, individual: 3C 279 [Galaxies], LONG, VARIABILITY, galaxies: individual: 3C 279, GAMMA-RAY, QUASARS, 13. Climate action, Space and Planetary Science, techniques: interferometric, Brightness temperature, ACCRETION DISKS, interferometric [Techniques], jets [Galaxies], RELATIVISTIC JETS, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Open Access funding provided by Max Planck Society.--All authors: Kim, Jae-Young; Krichbaum, Thomas P.; Broderick, Avery E.; Wielgus, Maciek; Blackburn, Lindy; Gómez, José L.; Johnson, Michael D.; Bouman, Katherine L.; Chael, Andrew; Akiyama, Kazunori; Jorstad, Svetlana; Marscher, Alan P.; Issaoun, Sara; Janssen, Michael; Chan, Chi-kwan; Savolainen, Tuomas; Pesce, Dominic W.; Özel, Feryal; Alberdi, Antxon; Alef, Walter Asada, Keiichi; Azulay, Rebecca; Baczko, Anne-Kathrin; Ball, David; Baloković, Mislav; Barrett, John; Bintley, Dan; Boland, Wilfred; Bower, Geoffrey C.; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broguiere, Dominique; Bronzwaer, Thomas; Byun, Do-Young; Carlstrom, John E.; Chatterjee, Shami; Chatterjee, Koushik; Chen, Ming-Tang; Chen, Yongjun; Cho, Ilje; Christian, Pierre; Conway, John E.; Cordes, James M.; Crew, Geoffrey B.; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Doeleman, Sheperd S.; Eatough, Ralph P.; Falcke, Heino; Fish, Vincent L.; Fomalont, Ed; Fraga-Encinas, Raquel; Friberg, Per; Fromm, Christian M.; Galison, Peter; Gammie, Charles F.; García, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gold, Roman; Gómez-Ruiz, Arturo I.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Hecht, Michael H.; Hesper, Ronald; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Inoue, Makoto; James, David J.; Jannuzi, Buell T.; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Junhan; Kim, Jongsoo; Kino, Motoki; Koay, Jun Yi; Koch, Patrick M.; Koyama, Shoko; Kramer, Michael; Kramer, Carsten; Kuo, Cheng-Yu; Lauer, Tod R.; Lee, Sang-Sung; Li, Yan-Rong; Li, Zhiyuan; Lindqvist, Michael; Lico, Rocco; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin; Lu, Ru-Sen; MacDonald, Nicholas R.; Mao, Jirong; Markoff, Sera; Marrone, Daniel P.; Martí-Vidal, Iván; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Mizuno, Yosuke; Mizuno, Izumi; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Musoke, Gibwa; Müller, Cornelia; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Okino, Hiroki; Olivares, Héctor; Ortiz-León, Gisela N.; Oyama, Tomoaki; Palumbo, Daniel C. M.; Park, Jongho; Patel, Nimesh; Pen, Ue-Li; Piétu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; 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; Ros, Eduardo; Rose, Mel; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruszczyk, Chet; Ryan, Benjamin R.; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Arguelles, David; Sasada, Mahito; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Tazaki, Fumie; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Toma, Kenji; Torne, Pablo; Trent, Tyler; Traianou, Efthalia; Trippe, Sascha; Tsuda, Shuichiro; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Wardle, John; Ward-Thompson, Derek; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wong, George N.; Wu, Qingwen; Yoon, Doosoo; Young, André; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhao, Guangyao; Zhao, Shan-Shan; Zhu, Ziyan; Algaba, Juan-Carlos; Allardi, Alexander; Amestica, Rodrigo; Anczarski, Jadyn; Bach, Uwe; Baganoff, Frederick K.; Beaudoin, Christopher; Benson, Bradford A.; Berthold, Ryan; Blanchard, Jay M.; Blundell, Ray; Bustamente, Sandra; Cappallo, Roger; Castillo-Domínguez, Edgar; Chang, Chih-Cheng; Chang, Shu-Hao; Chang, Song-Chu; Chen, Chung-Chen; Chilson, Ryan; Chuter, Tim C.; Rosado, Rodrigo Córdova; Coulson, Iain M.; Crowley, Joseph; Derome, Mark; Dexter, Matthew; Dornbusch, Sven; Dudevoir, Kevin A.; Dzib, Sergio A.; Eckart, Andreas; Eckert, Chris; Erickson, Neal R.; Everett, Wendeline B.; Faber, Aaron; Farah, Joseph R.; Fath, Vernon; Folkers, Thomas W.; Forbes, David C.; Freund, Robert; Gale, David M.; Gao, Feng; Geertsema, Gertie; Graham, David A.; Greer, Christopher H.; Grosslein, Ronald; Gueth, Frédéric; Haggard, Daryl; Halverson, Nils W.; Han, Chih-Chiang; Han, Kuo-Chang; Hao, Jinchi; Hasegawa, Yutaka; Henning, Jason W.; Hernández-Gómez, Antonio; Herrero-Illana, Rubén; Heyminck, Stefan; Hirota, Akihiko; Hoge, James; Huang, Yau-De; Violette Impellizzeri, C. M.; Jiang, Homin; John, David; Kamble, Atish; Keisler, Ryan; Kimura, Kimihiro; Kono, Yusuke; Kubo, Derek; Kuroda, John; Lacasse, Richard; Laing, Robert A.; Leitch, Erik M.; Li, Chao-Te; Lin, Lupin C. -C.; Liu, Ching-Tang; Liu, Kuan-Yu; Lu, Li-Ming; Marson, Ralph G.; Martin-Cocher, Pierre L.; Massingill, Kyle D.; Matulonis, Callie; McColl, Martin P.; McWhirter, Stephen R.; Messias, Hugo; Meyer-Zhao, Zheng; Michalik, Daniel; Montaña, Alfredo; Montgomerie, William; Mora-Klein, Matias; Muders, Dirk; Nadolski, Andrew; Navarro, Santiago; Neilsen, Joseph; Nguyen, Chi H.; Nishioka, Hiroaki; Norton, Timothy; Nowak, Michael A.; Nystrom, George; Ogawa, Hideo; Oshiro, Peter; Oyama, Tomoaki; Parsons, Harriet; Peñalver, Juan; Phillips, Neil M.; Poirier, Michael; Pradel, Nicolas; Primiani, Rurik A.; Raffin, Philippe A.; Rahlin, Alexandra S.; Reiland, George; Risacher, Christopher; Ruiz, Ignacio; Sáez-Madaín, Alejandro F.; Sassella, Remi; Schellart, Pim; Shaw, Paul; Silva, Kevin M.; Shiokawa, Hotaka; Smith, David R.; Snow, William; Souccar, Kamal; Sousa, Don; Sridharan, Tirupati K.; Srinivasan, Ranjani; Stahm, William; Stark, Antony A.; Story, Kyle; Timmer, Sjoerd T.; Vertatschitsch, Laura; Walther, Craig; Wei, Ta-Shun; Whitehorn, Nathan; Whitney, Alan R.; Woody, David P.; Wouterloot, Jan G. A.; Wright, Melvin; Yamaguchi, Paul; Yu, Chen-Yu; Zeballos, Milagros; Zhang, Shuo; Ziurys, Lucy; Event Horizon Telescope Collaboration, 3C 279 is an archetypal blazar with a prominent radio jet that show broadband flux density variability across the entire electromagnetic spectrum. We use an ultra-high angular resolution technique - global Very Long Baseline Interferometry (VLBI) at 1.3mm (230 GHz) - to resolve the innermost jet of 3C 279 in order to study its fine-scale morphology close to the jet base where highly variable-ray emission is thought to originate, according to various models. The source was observed during four days in April 2017 with the Event Horizon Telescope at 230 GHz, including the phased Atacama Large Millimeter/submillimeter Array, at an angular resolution of ∼20 μas (at a redshift of z = 0:536 this corresponds to ∼0:13 pc ∼ 1700 Schwarzschild radii with a black hole mass MBH = 8 × 108 M⊙). Imaging and model-fitting techniques were applied to the data to parameterize the fine-scale source structure and its variation.We find a multicomponent inner jet morphology with the northernmost component elongated perpendicular to the direction of the jet, as imaged at longer wavelengths. The elongated nuclear structure is consistent on all four observing days and across diffierent imaging methods and model-fitting techniques, and therefore appears robust. Owing to its compactness and brightness, we associate the northern nuclear structure as the VLBI "core". This morphology can be interpreted as either a broad resolved jet base or a spatially bent jet.We also find significant day-to-day variations in the closure phases, which appear most pronounced on the triangles with the longest baselines. Our analysis shows that this variation is related to a systematic change of the source structure. Two inner jet components move non-radially at apparent speeds of ∼15 c and ∼20 c (∼1:3 and ∼1:7 μas day-1, respectively), which more strongly supports the scenario of traveling shocks or instabilities in a bent, possibly rotating jet. The observed apparent speeds are also coincident with the 3C 279 large-scale jet kinematics observed at longer (cm) wavelengths, suggesting no significant jet acceleration between the 1.3mm core and the outer jet. The intrinsic brightness temperature of the jet components are ≤1010 K, a magnitude or more lower than typical values seen at ≥7mm wavelengths. The low brightness temperature and morphological complexity suggest that the core region of 3C 279 becomes optically thin at short (mm) wavelengths. © J.-Y. Kim et al. 2020., The authors of the present paper thank the following organizations and programs: the Academy of Finland (projects 274477, 284495, 312496); the Advanced European Network of E-infrastructures for Astronomy with the SKA (AENEAS) project, supported by the European Commission Framework Programme Horizon 2020 Research and Innovation action under grant agreement 731016; the Alexander von Humboldt Stiftung; the Black Hole Initiative at Harvard University, through a grant (60477) from the John Templeton Foundation; the China Scholarship Council; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT, Chile, via PIA ACT172033, Fondecyt projects 1171506 and 3190878, BASAL AFB-170002, ALMA-conicyt 31140007); Consejo Nacional de Ciencia y Tecnologia (CONACYT, Mexico, projects 104497, 275201, 279006, 281692); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Direccion General de Asuntos del Personal Academico -Universidad Nacional Autonoma de Mexico (DGAPA -UNAM, project IN112417); the European Research Council Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); the Gordon and Betty Moore Foundation (grants GBMF-3561, GBMF-5278); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; the Jansky Fellowship program of the National Radio Astronomy Observatory (NRAO); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-inAid for JSPS Research Fellowship (JP17J08829); the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJSSW-SLH057, QYZDJ-SSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Malaysian Fundamental Research Grant Scheme (FRGS, grant FRGS/1/2019/STG02/UM/02/6); the Max-PlanckGesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP18K13594, JP18K03656, JP18H03721, 18K03709, 18H01245, 25120007); the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (105-2112-M-001-025-MY3, 106-2112-M-001-011, 106-2119-M-001-027, 107-2119-M-001-017, 107-2119-M-001-020, and 107-2119-M-110-005); the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC17K0649 and Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. r , for NASA, under contract NAS5-26555); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1312651, AST-1337663, AST-1440254, AST-1555365, AST-1715061, AST-1615796, AST-1716327, OISE-1743747, AST-1816420); the Natural Science Foundation of China (grants 11573051, 11633006, 11650110427, 10625314, 11721303, 11725312, 11933007); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, 2015-R1D1A1A01056807, the Korea Research Fellowship Program: NRF-2015H1D3A1066561); the Netherlands Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and Spinoza Prize SPI 78-409; the New Scientific Frontiers with Precision Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Technology (DST) of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648) the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Russian Science Foundation (grant 17-12-01029); the Spanish Ministerio de Economia y Competitividad (grants PGC2018-098915-B-C21, AYA201680889-P); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709); the Toray Science Foundation; the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001)); the Italian Ministero dell'Istruzione Universita e Ricerca through the grant Progetti Premiali 2012-iALMA (CUP C52I13000140001); the European Union's Horizon 2020 research and innovation programme under grant agreement No 730562 RadioNet; ALMA North America Development Fund; the Academia Sinica; Chandra TM6-17006X; the GenT Program (Generalitat Valenciana) Project CIDEGENT/2018/021. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI1743442. XSEDE Stampede2 resource at TACC was allocated through TGAST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. The simulations were performed in part on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, and on the HazelHen cluster at the HLRS in Stuttgart. This research was enabled in part by support provided by Compute Ontario (http://computeontario. r ca), Calcul Quebec (http://www.calculquebec.ca) and Compute Canada (http://www.computecanada.ca).We thank the sta ff at the participating observatories, correlation centers, and institutions for their enthusiastic support. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.01154.V, ADS/JAO.ALMA#2016.1.01176.V. ALMA is a partnership of the European Southern Observatory (ESO; Europe, representing its member states), NSF, and National Institutes of Natural Sciences of Japan, together with National Research Council (Canada), Ministry of Science and Technology (MOST; Taiwan), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), and Korea Astronomy and Space Science Institute (KASI; Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities, Inc. (AUI)/NRAO, and the National Astronomical Observatory of Japan (NAOJ). The NRAO is a facility of the NSF operated under cooperative agreement by AUI. APEX is a collaboration between the Max-Planck-Institut fur Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key R&D Program (No. 2017YFA0402700) of China. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrofisica, Optica, y Electronica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30-m telescope on Pico Veleta, Spain is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck-Gesellschaft, Germany) and IGN (Instituto Geografico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. The SPT is supported by the National Science Foundation through grant PLR1248097. Partial support is also provided by the NSF Physics Frontier Center grant PHY-1125897 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation and the Gordon and Betty Moore Foundation grant GBMF 947. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. The EHTC has received generous donations of FPGA chips from Xilinx Inc., under the Xilinx University Program. The EHTC has benefited from technology shared under open-source license by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER). The EHT project is grateful to T4Science and Microsemi for their assistance with Hydrogen Masers. This research has made use of NASA's Astrophysics Data System. We gratefully acknowledge the support provided by the extended sta ff of the ALMA, both from the inception of the ALMA Phasing Project through the observational campaigns of 2017 and 2018. We would like to thank A. Deller and W. Brisken for EHT-specific support with the use of DiFX. We acknowledge the significance that Maunakea, where the SMA and JCMT EHT stations are located, has for the indigenous Hawaiian people. r This research has made use of data obtained with the Global Millimeter VLBI Array (GMVA), which consists of telescopes operated by the MPIfR, IRAM, Onsala, Metsahovi, Yebes, the Korean VLBI Network, the Green Bank Observatory and the Very Long Baseline Array (VLBA). The VLBA is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated by Associated Universities, Inc. The data were correlated at the correlator of the MPIfR in Bonn, Germany. This study makes use of 43 GHz VLBA data from the VLBA-BU Blazar Monitoring Program (VLBABU-BLAZAR; http://www.bu.edu/blazars/VLBAproject.html), funded by NASA through the Fermi Guest Investigator Program.
Published: 2020
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7. First M87 Event Horizon Telescope Results. I. the Shadow of the Supermassive Black Hole

Author: Olivier Gentaz, David J. James, Hector Olivares, John E. Barrett, Alan P. Marscher, C. M. Violette Impellizzeri, Peter Oshiro, Peter Galison, Tyler Trent, Sang-Sung Lee, Arturo I. Gómez-Ruiz, Satoki Matsushita, Carsten Kramer, Scott Paine, Dimitrios Psaltis, Mareki Honma, Kazi L.J. Rygl, Shuo Zhang, Jan Wagner, Daniel P. Marrone, Ryan Chilson, Jorge A. Preciado-López, Christopher Beaudoin, Sara Issaoun, André Young, A. A. Stark, Jordy Davelaar, Hiroshi Nagai, Zhiqiang Shen, Pablo Torne, Chris Eckert, John Wardle, Ranjani Srinivasan, David M. Gale, David Ball, Alan L. Roy, Lupin C.C. Lin, Thomas Bronzwaer, Kazunori Akiyama, W. B. Everett, Li Ming Lu, Ta Shun Wei, Sheperd S. Doeleman, Shu Hao Chang, Roberto Garcia, Richard L. Plambeck, Maciek Wielgus, Iniyan Natarajan, Raquel Fraga-Encinas, Hiroaki Nishioka, Mark G. Rawlings, Tirupati K. Sridharan, Geoffrey B. Crew, Vernon Fath, Michael H. Hecht, Frederic Gueth, Jun Yi Koay, David Sánchez-Arguelles, Chih Chiang Han, Michael Kramer, Mariafelicia De Laurentis, Kuo Liu, Oliver Porth, Jae-Young Kim, Ilje Cho, Shan Shan Zhao, Hotaka Shiokawa, Martin P. McColl, Song Chu Chang, Lei Huang, William Stahm, Makoto Inoue, Svetlana G. Jorstad, Andrew Chael, Chih Cheng Chang, Thomas P. Krichbaum, Dominic W. Pesce, Chung Chen Chen, Laura Vertatschitsch, Jonathan Weintroub, Alejandro F. Sáez-Madain, Sera Markoff, Shuichiro Tsuda, Ryan Berthold, Chao-Te Li, M. C. H. Wright, Daniel R. van Rossum, J. Peñalver, Neal R. Erickson, Remo P. J. Tilanus, John E. Carlstrom, Roger Deane, Minfeng Gu, Michael Titus, Laurent Loinard, Lia Medeiros, C. Y. Kuo, Iain Coulson, Michael Janssen, Ben Prather, Katherine L. Bouman, Lucy M. Ziurys, Norbert Wex, Freek Roelofs, Feng Gao, Yau De Huang, Dan Bintley, N. W. Halverson, Benjamin R. Ryan, Nimesh A. Patel, Aaron Faber, Mansour Karami, Robert Freund, Ming-Tang Chen, K. T. Story, Gertie Geertsema, Daryl Haggard, Paul Shaw, Ronald Grosslein, S. A. Dzib, Joseph Crowley, Kuo Chang Han, Shoko Koyama, José L. Gómez, Chet Ruszczyk, David R. Smith, Michael Bremer, Daniel Michalik, James Hoge, Karl M. Menten, Juan-Carlos Algaba, Aristeidis Noutsos, William Snow, Thomas W. Folkers, Masanori Nakamura, Homin Jiang, James M. Cordes, Uwe Bach, Christopher Risacher, Rurik A. Primiani, Pierre Christian, David H. Hughes, Wen Ping Lo, Geoffrey C. Bower, James M. Moran, Ciriaco Goddi, Yi Chen, Christopher Greer, Roger J. Cappallo, Ilse van Bemmel, Andreas Eckart, Ziyan Zhu, Chi H. Nguyen, Rubén Herrero-Illana, Robert Wharton, Antonio Hernández-Gómez, Bart Ripperda, Dominique Broguiere, Pim Schellart, Mark Derome, Chih-Wei Locutus Huang, Chen Yu Yu, Kuan Yu Liu, Lijing Shao, Christiaan D. Brinkerink, Michael D. Johnson, Mark Kettenis, Michael Lindqvist, Frederick K. Baganoff, John Conway, Remi Sassella, Nathan Whitehorn, Eduardo Ros, David P. Woody, Jessica Dempsey, Gopal Narayanan, Elisabetta Liuzzo, Akihiko Hirota, D. A. Graham, Hiroki Okino, Vincent Piétu, Alexander W. Raymond, Gregory Desvignes, Anne Kathrin Baczko, Arash Roshanineshat, Kevin M. Silva, Timothy Norton, Heino Falcke, Aleksandar Popstefanija, Ken H. Young, Per Friberg, Paul Yamaguchi, Derek Kubo, E. Castillo-Domínguez, Jason W. Henning, R. Laing, Kimihiro Kimura, Rodrigo Córdova Rosado, Roman Gold, Helge Rottmann, Silke Britzen, J. Anton Zensus, Roger Brissenden, Ru-Sen Lu, Ye-Fei Yuan, F. Peter Schloerb, Stephen R. McWhirter, Joseph R. Farah, Ue-Li Pen, Yosuke Mizuno, Charles F. Gammie, Mel Rose, Harriet Parsons, Venkatessh Ramakrishnan, Philippe Raffin, Ignacio Ruiz, Mahito Sasada, Kamal Souccar, Joseph Neilsen, J. G. A. Wouterloot, Jirong Mao, Colin J. Lonsdale, Feng Yuan, Jadyn Anczarski, Lindy Blackburn, N. Phillips, Don Sousa, Ramesh Narayan, Alan R. Whitney, Paul T. P. Ho, Kyle D. Massingill, Patrick M. Koch, Taehyun Jung, Erik M. Leitch, Junhan Kim, Nicolas Pradel, Kevin A. Dudevoir, Britton Jeter, Jason SooHoo, Tomohisa Kawashima, T. M. Crawford, Mark Gurwell, A. Montaña, R. P. Eatough, Sascha Trippe, Ivan Marti-Vidal, Dirk Muders, Craig Walther, Atish Kamble, Qingwen Wu, Chunchong Ni, George Nystrom, Yusuke Kono, Ryan Keisler, Huib Jan van Langevelde, Stefan Heyminck, Kenji Toma, Do-Young Byun, Sjoerd T. Timmer, Antxon Alberdi, Hung Yi Pu, Hugo Messias, Feryal Özel, Kotaro Moriyama, John David, M. Poirier, Mislav Baloković, Fumie Tazaki, Keiichi Asada, S. Sánchez, Wu Jiang, Tomoaki Oyama, Shami Chatterjee, Des Small, Richard Lacasse, Ray Blundell, Motoki Kino, Michael A. Nowak, Jason Dexter, Walter Alef, Jinchi Hao, Zhiyuan Li, Garrett K. Keating, Christian M. Fromm, Cornelia Müller, Ching Tang Liu, Alexandra S. Rahlin, William Montgomerie, Andrei P. Lobanov, Bradford Benson, George N. Wong, Kazuhiro Hada, Sven Dornbusch, George Reiland, Boris Georgiev, Luciano Rezzolla, Jongsoo Kim, W. Boland, Ramprasad Rao, Guang-Yao Zhao, Buell T. Jannuzi, Sandra Bustamente, Daniel C. M. Palumbo, Tod R. Lauer, Karl Friedrich Schuster, Ronald Hesper, Zheng Meyer-Zhao, John Kuroda, Ramesh Karuppusamy, Pierre Martin-Cocher, Chi-kwan Chan, Timothy C. Chuter, Izumi Mizuno, Vincent L. Fish, Yutaka Hasegawa, Roberto Neri, Matthew R. Dexter, Paul Tiede, Rodrigo Amestica, S. Navarro, William T. Freeman, Callie Matulonis, Luis C. Ho, Hideo Ogawa, Shiro Ikeda, Ralph G. Marson, A. Nadolski, J. Blanchard, Ed Fomalont, Monika Moscibrodzka, Nicholas R. MacDonald, Gisela N. Ortiz-León, Bong Won Sohn, David C. Forbes, Lynn D. Matthews, Avery E. Broderick, Ziri Younsi, Tuomas Savolainen, Neil M. Nagar, Alexander Allardi, M. Mora-Klein, Yuzhu Cui, Yan-Rong Li, Koushik Chatterjee, Rebecca Azulay, M. Zeballos, Alan E. E. Rogers, Event Horizon Telescope Collaboration, T., Akiyama, K., Alberdi, A., Alef, W., Asada, K., Azulay, R., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Bintley, D., Blackburn, L., Boland, W., Bouman, K. L., Bower, G. C., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D. -Y., Carlstrom, J. E., Chael, A., Chan, C. -K., Chatterjee, S., Chatterjee, K., Chen, M. -T., Chen, Y., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crew, G. B., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Fish, V. L., Fomalont, E., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Gomez, J. L., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gu, M., Gurwell, M., Hada, K., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. 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W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Prather, B., Preciado-Lopez, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Ryan, B. R., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sasada, M., Savolainen, T., Schloerb, F. P., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Tazaki, F., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Trent, T., Trippe, S., Tsuda, S., Bemmel, I. V., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Young, K., Young, A., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhao, G., Zhao, S. -S., Zhu, Z., Algaba, J. -C., Allardi, A., Amestica, R., Anczarski, J., Bach, U., Baganoff, F. K., Beaudoin, C., Benson, B. A., Berthold, R., Blanchard, J. M., Blundell, R., Bustamente, S., Cappallo, R., Castillo-Dominguez, E., Chang, C. -C., Chang, S. -H., Chang, S. -C., Chen, C. -C., Chilson, R., Chuter, T. C., Rosado, R. C., Coulson, I. M., Crawford, T. M., Crowley, J., David, J., Derome, M., Dexter, M., Dornbusch, S., Dudevoir, K. A., Dzib, S. A., Eckart, A., Eckert, C., Erickson, N. R., Everett, W. B., Faber, A., Farah, J. R., Fath, V., Folkers, T. W., Forbes, D. C., Freund, R., Gomez-Ruiz, A. I., Gale, D. M., Gao, F., Geertsema, G., Graham, D. A., Greer, C. H., Grosslein, R., Gueth, F., Haggard, D., Halverson, N. W., Han, C. -C., Han, K. -C., Hao, J., Hasegawa, Y., Henning, J. W., Hernandez-Gomez, A., Herrero-Illana, R., Heyminck, S., Hirota, A., Hoge, J., Huang, Y. -D., Impellizzeri, C. M. V., Jiang, H., Kamble, A., Keisler, R., Kimura, K., Kono, Y., Kubo, D., Kuroda, J., Lacasse, R., Laing, R. A., Leitch, E. M., Li, C. -T., Lin, L. C. -C., Liu, C. -T., Liu, K. -Y., Lu, L. -M., Marson, R. G., Martin-Cocher, P. L., Massingill, K. D., Matulonis, C., Mccoll, M. P., Mcwhirter, S. R., Messias, H., Meyer-Zhao, Z., Michalik, D., Montana, A., Montgomerie, W., Mora-Klein, M., Muders, D., Nadolski, A., Navarro, S., Neilsen, J., Nguyen, C. H., Nishioka, H., Norton, T., Nowak, M. A., Nystrom, G., Ogawa, H., Oshiro, P., Parsons, H., Paine, S. N., Penalver, J., Phillips, N. M., Poirier, M., Pradel, N., Primiani, R. A., Raffin, P. A., Rahlin, A. S., Reiland, G., Risacher, C., Ruiz, I., Saez-Madain, A. F., Sassella, R., Schellart, P., Shaw, P., Silva, K. M., Shiokawa, H., Smith, D. R., Snow, W., Souccar, K., Sousa, D., Sridharan, T. K., Srinivasan, R., Stahm, W., Stark, A. A., Story, K., Timmer, S. T., Vertatschitsch, L., Walther, C., Wei, T. -S., Whitehorn, N., Whitney, A. R., Woody, D. P., Wouterloot, J. G. A., Wright, M., Yamaguchi, P., Yu, C. -Y., Zeballos, M., Zhang, S., Ziurys, L., Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Instituto de RadioAstronomía Milimétrica (IRAM), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Event Horizon Telescope, Academy of Finland, European Commission, Alexander von Humboldt Foundation, John Templeton Foundation, China Scholarship Council, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Gordon and Betty Moore Foundation, Istituto Nazionale di Fisica Nucleare, Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Max Planck Society, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Science Foundation (US), National Natural Science Foundation of China, Natural Sciences and Engineering Research Council of Canada, National Research Foundation of Korea, Netherlands Organization for Scientific Research, National Research Foundation (South Africa), Russian Science Foundation, Ministero dell'Istruzione, dell'Università e della Ricerca, Alberdi, Antxón, Gómez Fernández, J. L., Alberdi, Antxón [0000-0002-9371-1033], Gómez Fernández, J. L. [0000-0003-4190-7613], Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Anne Lähteenmäki Group, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, Astronomy, High Energy Astrophys. & Astropart. Phys (API, FNWI), and Gravitation and Astroparticle Physics Amsterdam
Subjects: 010504 meteorology & atmospheric sciences, individual (M87) [galaxies], Event horizon, Astronomy, black hole physics, jets [galaxies], galaxies: individual, Astrophysics, high-resolution, 7. Clean energy, 01 natural sciences, Photon sphere, General Relativity and Quantum Cosmology, accretion, sagittarius-a-asterisk, 010303 astronomy & astrophysics, galactic-center, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, radio-sources, accretion disks, Galactic Center, grmhd simulations, 3. Good health, energy-distributions, active [galaxies], Anatomy, Astrophysics - High Energy Astrophysical Phenomena, Active galactic nucleus, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, galaxies: individual: M87, galaxies: individual (M87), Cell and Developmental Biology, 0103 physical sciences, (M87), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Event Horizon Telescope, Supermassive black hole, ghz vlbi observations, faraday-rotation, Astronomy and Astrophysics, galaxies: jets, Astrophysics - Astrophysics of Galaxies, Black hole, Rotating black hole, Space and Planetary Science, gravitation, Astrophysics of Galaxies (astro-ph.GA), advection-dominated accretion, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ionized-gas
Abstract: When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. This allows us to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87. We have resolved the central compact radio source as an asymmetric bright emission ring with a diameter of 42 ± 3 μas, which is circular and encompasses a central depression in brightness with a flux ratio 10:1. The emission ring is recovered using different calibration and imaging schemes, with its diameter and width remaining stable over four different observations carried out in different days. Overall, the observed image is consistent with expectations for the shadow of a Kerr black hole as predicted by general relativity. The asymmetry in brightness in the ring can be explained in terms of relativistic beaming of the emission from a plasma rotating close to the speed of light around a black hole. We compare our images to an extensive library of ray-traced general-relativistic magnetohydrodynamic simulations of black holes and derive a central mass of M = (6.5 ± 0.7) × 109 Me. Our radiowave observations thus provide powerful evidence for the presence of supermassive black holes in centers of galaxies and as the central engines of active galactic nuclei. They also present a new tool to explore gravity in its most extreme limit and on a mass scale that was so far not accessible.© 2019. The American Astronomical Society, The authors of this Letter thank the following organizations and programs: the Academy of Finland (projects 274477, 284495, 312496); the Advanced European Network of E-infrastructures for Astronomy with the SKA (AENEAS) project, supported by the European Commission Framework Programme Horizon 2020 Research and Innovation action under grant agreement 731016; the Alexander von Humboldt Stiftung; the Black Hole Initiative at Harvard University, through a grant (60477) from the John Templeton Foundation; the China Scholarship Council; Comisión Nacional de Investigación Científica y Tecnológica (CONICYT, Chile, via PIA ACT172033, Fondecyt 1171506, BASAL AFB170002, ALMA-conicyt 31140007); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects 104497, 275201, 279006, 281692); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional 9 The Astrophysical Journal Letters, 875:L1 (17pp), 2019 April 10 The EHT Collaboration et al. Autónoma de México (DGAPA-UNAM, project IN112417); the European Research Council (ERC) Synergy Grant “BlackHoleCam: Imaging the Event Horizon of Black Holes” (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177; the Gordon and Betty Moore Foundation (grants GBMF-3561, GBMF-5278); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; the Jansky Fellowship program of the National Radio Astronomy Observatory (NRAO); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); JSPS Overseas Research Fellowships; the Key Research Program of Frontier Sciences, Chinese, Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJ-SSW-SYS008); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP18K13594, JP18K03656, JP18H03721, 18K03709, 18H01245, 25120007); the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (105-2112-M-001-025-MY3, 106-2112-M001-011, 106-2119-M-001-027, 107-2119-M-001-017, 107- 2119-M-001-020, and 107-2119-M-110-005); the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC17K0649); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST0705062, AST-0905844, AST-0922984, AST-1126433, AST1140030, DGE-1144085, AST-1207704, AST-1207730, AST1207752, MRI-1228509, OPP-1248097, AST-1310896, AST1312651, AST-1337663, AST-1440254, AST-1555365, AST1715061, AST-1615796, AST-1614868, AST-1716327, OISE1743747, AST-1816420); the Natural Science Foundation of China (grants 11573051, 11633006, 11650110427, 10625314, 11721303, 11725312, 11873028, 11873073, U1531245, 11473010); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (grant 2015-R1D1A1A01056807, the Global PhD Fellowship Grant: NRF-2015H1A2A1033752, and the Korea Research Fellowship Program: NRF-2015H1D3A1066561); the Netherlands Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and Spinoza Prize (SPI 78-409); the New Scientific Frontiers with Precision, Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Technology (DST) of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Economic Development, Job Creation and Trade); the Russian Science Foundation (grant 17-12-01029); the Spanish Ministerio de Economía y Competitividad (grants AYA2015-63939-C2-1-P, AYA2016-80889-P); the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709); the Toray Science Foundation; the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001)); the Italian Ministero dell’Istruzione Università e Ricerca through the grant Progetti Premiali 2012-iALMA (CUP C52I13000140001); the European Unionʼs Horizon 2020 research and innovation programme under grant agreement No 730562 RadioNet; ALMA North America Development Fund; Chandra TM6-17006X
Published: 2019
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8. Implementation of automated vanilla pollination robotic crane prototype

Author: John Kuroda, Tuan Giang, and T. Shaneyfelt
Subjects: Engineering, Pollination, business.industry, Production cost, 010401 analytical chemistry, Greenhouse, 010402 general chemistry, 01 natural sciences, Automation, Manufacturing engineering, 0104 chemical sciences, Robot, business, Simulation, Hand-pollination
Abstract: Vanilla is among the most expensive and most produced spices in the world today. Hand pollination is required in most areas around the globe. Because of the amount of manual labour required for hand pollination automation should reduce the production cost and bring more organic vanilla to the spice market displacing adulterated products. A vanilla crane system for pollination was proposed and simulated by Shaneyfelt et al. in 2013. This paper presents the development of a physical prototype of the system as an undergraduate project.
Published: 2017
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9. First M87 Event Horizon Telescope Results. II. Array and Instrumentation

Author: Monika Moscibrodzka, Elisabetta Liuzzo, F. Peter Schloerb, John Conway, Remi Sassella, Eduardo Ros, Kevin M. Silva, Christopher Beaudoin, Minfeng Gu, Stephen R. McWhirter, Nicholas R. MacDonald, Derek Kubo, E. Castillo-Domínguez, Iain Coulson, Katherine L. Bouman, John E. Barrett, Peter Oshiro, Peter Galison, Walter Alef, Ignacio Ruiz, N. Phillips, Gisela N. Ortiz-León, Ye-Fei Yuan, Arturo I. Gómez-Ruiz, Scott Paine, Dimitrios Psaltis, Mareki Honma, Juan-Carlos Algaba, Daniel P. Marrone, Alexandra S. Rahlin, Li Ming Lu, Iniyan Natarajan, Thomas W. Folkers, Zhiqiang Shen, Mariafelicia De Laurentis, Kuo Liu, Chao-Te Li, M. C. H. Wright, Mansour Karami, José L. Gómez, Roger J. Cappallo, Roger Deane, Lucy M. Ziurys, Yi Chen, Christopher Greer, William Montgomerie, Andrei P. Lobanov, George N. Wong, Bong Won Sohn, Huib Jan van Langevelde, Mark Gurwell, Ivan Marti-Vidal, Ilje Cho, Hotaka Shiokawa, Martin P. McColl, Makoto Inoue, Shu Hao Chang, K. T. Story, Joseph Crowley, C. M.Violette Impellizzeri, Kazuhiro Hada, Michael Kramer, Ranjani Srinivasan, David Ball, Keiichi Asada, Des Small, Hung Yi Pu, John David, Tomoaki Oyama, Svetlana G. Jorstad, Boris Georgiev, Sheperd S. Doeleman, Oliver Porth, Nathan Whitehorn, Alan L. Roy, Kazunori Akiyama, W. B. Everett, Maciek Wielgus, Don Sousa, J. Blanchard, Ray Blundell, Motoki Kino, Karl Friedrich Schuster, Ronald Hesper, Zheng Meyer-Zhao, John Kuroda, Heino Falcke, Chung Chen Chen, Carsten Kramer, Thomas P. Krichbaum, R. P. Eatough, S. Sánchez, Roberto Garcia, Jan Wagner, Ramesh Karuppusamy, Raquel Fraga-Encinas, Hiroaki Nishioka, Mark G. Rawlings, Ed Fomalont, W. Boland, Ramprasad Rao, Timothy Norton, Ching Tang Liu, James M. Cordes, Bradford Benson, Dominic W. Pesce, Yan-Rong Li, Geoffrey B. Crew, Vernon Fath, Frederic Gueth, David Sánchez-Arguelles, Roger Brissenden, Chi-kwan Chan, Timothy C. Chuter, Qingwen Wu, Chunchong Ni, Yuzhu Cui, Guang-Yao Zhao, Harriet Parsons, Ken H. Young, Paul Yamaguchi, Mahito Sasada, Daniel R. van Rossum, Yusuke Kono, Ryan Keisler, Masanori Nakamura, Patrick M. Koch, Nicolas Pradel, Ramesh Narayan, Rodrigo Córdova Rosado, Jordy Davelaar, Hiroshi Nagai, Chih Cheng Chang, Joseph R. Farah, Ben Prather, Laura Vertatschitsch, Britton Jeter, Kuo Chang Han, Shoko Koyama, William Snow, Lindy Blackburn, Erik M. Leitch, Rurik A. Primiani, Pierre Christian, Kyle D. Massingill, Shiro Ikeda, Remo P. J. Tilanus, S. A. Dzib, Charles F. Gammie, Ziyan Zhu, Ralph G. Marson, Aleksandar Popstefanija, Helge Rottmann, Chris Eckert, Lupin C.C. Lin, Michael H. Hecht, Silke Britzen, J. Anton Zensus, Christian M. Fromm, Sera Markoff, Wu Jiang, Cornelia Müller, A. Nadolski, David H. Hughes, Zhiyuan Li, Ue-Li Pen, Yosuke Mizuno, Sascha Trippe, Jinchi Hao, Gertie Geertsema, Garrett K. Keating, Lei Huang, Chi H. Nguyen, Koushik Chatterjee, Andrew Chael, Norbert Wex, Ronald Grosslein, Nimesh A. Patel, Aaron Faber, Rebecca Azulay, Stefan Heyminck, Kenji Toma, Do-Young Byun, Christopher Risacher, Wen Ping Lo, Geoffrey C. Bower, James M. Moran, Tyler Trent, Satoki Matsushita, Bart Ripperda, Dominique Broguiere, Antxon Alberdi, Kazi L.J. Rygl, Chet Ruszczyk, T. K. Sridharan, Antony A. Stark, Michael Bremer, James Hoge, M. Zeballos, Kamal Souccar, Paul T. P. Ho, Atish Kamble, Ciriaco Goddi, Feng Gao, Yau De Huang, Dan Bintley, Alan E. E. Rogers, Ryan Chilson, Jorge A. Preciado-López, A. Montaña, Hector Olivares, Mark Derome, Michael Janssen, Robert Freund, Thomas Bronzwaer, Jun Yi Koay, Kevin A. Dudevoir, Roberto Neri, Buell T. Jannuzi, Sandra Bustamente, Mislav Baloković, S. Navarro, Shami Chatterjee, Tod R. Lauer, Alejandro F. Sáez-Madain, Sjoerd T. Timmer, Chih Chiang Han, John E. Carlstrom, Luis C. Ho, Hugo Messias, Feryal Özel, Shuichiro Tsuda, Ryan Berthold, Taehyun Jung, Akihiko Hirota, Richard Lacasse, D. A. Graham, Vincent Piétu, Homin Jiang, Shan Shan Zhao, Lia Medeiros, Song Chu Chang, Jae-Young Kim, Hideo Ogawa, Sara Issaoun, Kotaro Moriyama, Stephen Padin, Roman Gold, N. W. Halverson, Venkatessh Ramakrishnan, C. Y. Kuo, Benjamin R. Ryan, Jason Dexter, Paul Shaw, Alan R. Whitney, Karl M. Menten, Aristeidis Noutsos, Kimihiro Kimura, Mark Kettenis, Ming-Tang Chen, Jonathan Weintroub, Neal R. Erickson, Chen Yu Yu, David R. Smith, André Young, Luciano Rezzolla, Jongsoo Kim, M. Poirier, Robert Wharton, Daniel C. M. Palumbo, Pierre Martin-Cocher, Hiroki Okino, Yutaka Hasegawa, Kuan Yu Liu, David P. Woody, Sven Dornbusch, George Reiland, Arash Roshanineshat, Pablo Torne, Daniel Michalik, John Wardle, David M. Gale, Ta Shun Wei, Uwe Bach, Ilse van Bemmel, Izumi Mizuno, Vincent L. Fish, Antonio Hernández-Gómez, Matthew R. Dexter, Paul Tiede, Rodrigo Amestica, Pim Schellart, Michael D. Johnson, Mel Rose, Callie Matulonis, J. G. A. Wouterloot, Jason SooHoo, Tomohisa Kawashima, T. M. Crawford, Dirk Muders, Craig Walther, Richard L. Plambeck, William Stahm, George Nystrom, David C. Forbes, Lynn D. Matthews, Avery E. Broderick, Ziri Younsi, Tuomas Savolainen, Neil M. Nagar, Alexander Allardi, M. Mora-Klein, Fumie Tazaki, Michael Lindqvist, Per Friberg, Olivier Gentaz, David J. James, Alan P. Marscher, Sang-Sung Lee, Chih-Wei Locutus Huang, Lijing Shao, Christiaan D. Brinkerink, Jason W. Henning, R. Laing, Feng Yuan, Junhan Kim, J. Peñalver, Michael Titus, Freek Roelofs, Laurent Loinard, Rubén Herrero-Illana, Gopal Narayanan, Alexander W. Raymond, Gregory Desvignes, Anne Kathrin Baczko, Ru-Sen Lu, Philippe Raffin, Jirong Mao, Colin J. Lonsdale, Jessica Dempsey, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Instituto de RadioAstronomía Milimétrica (IRAM), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Event Horizon Telescope, Astronomy, Anne Lähteenmäki Group, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Academy of Finland, European Commission, Alexander von Humboldt Foundation, John Templeton Foundation, China Scholarship Council, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Gordon and Betty Moore Foundation, Istituto Nazionale di Fisica Nucleare, Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Max Planck Society, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Science Foundation (US), National Natural Science Foundation of China, Natural Sciences and Engineering Research Council of Canada, National Research Foundation of Korea, Netherlands Organization for Scientific Research, National Research Foundation (South Africa), Russian Science Foundation, Ministero dell'Istruzione, dell'Università e della Ricerca, Alberdi, Antxón [0000-0002-9371-1033], Gómez Fernández, J. L. [0000-0003-4190-7613], Event Horizon Telescope Collaboration, T., Akiyama, K., Alberdi, A., Alef, W., Asada, K., Azulay, R., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Bintley, D., Blackburn, L., Boland, W., Bouman, K. L., Bower, G. C., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D. -Y., Carlstrom, J. E., Chael, A., Chan, C. -K., Chatterjee, S., Chatterjee, K., Chen, M. -T., Chen, Y., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crew, G. B., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Fish, V. L., Fomalont, E., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Gomez, J. L., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gu, M., Gurwell, M., Hada, K., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Johnson, M. D., Jorstad, S., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Krichbaum, T. P., Kuo, C. -Y., Lauer, T. R., Lee, S. -S., Li, Y. -R., Li, Z., Lindqvist, M., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C., Lu, R. -S., Macdonald, N. R., Mao, J., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, Y., Mizuno, I., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Neri, R., Ni, C., Noutsos, A., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Patel, N., Pen, U. -L., Pesce, D. 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Subjects: 010504 meteorology & atmospheric sciences, individual (M87) [galaxies], Event horizon, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, interferometers [instrumentation], black hole physics, FOS: Physical sciences, galaxies: individual, General Relativity and Quantum Cosmology (gr-qc), galaxies: individual: M87, 01 natural sciences, General Relativity and Quantum Cosmology, galaxies: individual (M87), instrumentation: interferometer, 0103 physical sciences, Very-long-baseline interferometry, Angular resolution, Instrumentation (computer programming), instrumentation: interferometers, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, high angular resolution [echniques], Event Horizon Telescope, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Supermassive black hole, Galaxy: center, high angular resolution [techniques], techniques: high angular resolution, gravitational lensing: strong, Astronomy and Astrophysics, center [Galaxy], Hydrogen maser, black hole physic, Astrophysics - Astrophysics of Galaxies, echniques: high angular resolution, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), strong [gravitational lensing], Millimeter, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of ~1.3 mm, EHT angular resolution (λ/D) is ~25 μas, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letter we describe the system design of the EHT, detail the technology and instrumentation that enable observations, and provide measures of its performance. Meeting the EHT science objectives has required several key developments that have facilitated the robust extension of the VLBI technique to EHT observing wavelengths and the production of instrumentation that can be deployed on a heterogeneous array of existing telescopes and facilities. To meet sensitivity requirements, high-bandwidth digital systems were developed that process data at rates of 64 gigabit s−1, exceeding those of currently operating cm-wavelength VLBI arrays by more than an order of magnitude. Associated improvements include the development of phasing systems at array facilities, new receiver installation at several sites, and the deployment of hydrogen maser frequency standards to ensure coherent data capture across the array. These efforts led to the coordination and execution of the first Global EHT observations in 2017 April, and to event-horizon-scale imaging of the supermassive black hole candidate in M87.© 2019. The American Astronomical Society, The authors of this Letter thank the following organizations and programs: the Academy of Finland (projects 274477, 284495, 312496); the Advanced European Network of E-infrastructures for Astronomy with the SKA (AENEAS) project, supported by the European Commission Framework Programme Horizon 2020 Research and Innovation action under grant agreement 731016; the Alexander von Humboldt Stiftung; the Black Hole Initiative at Harvard University, through a grant (60477) from the John Templeton Foundation; the China Scholarship Council; Comisión Nacional de Investigación Científica y Tecnológica (CONICYT, Chile, via PIA ACT172033, Fondecyt 1171506, BASAL AFB170002, ALMA-conicyt 31140007); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects 104497, 275201, 279006, 281692); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional 9 The Astrophysical Journal Letters, 875:L1 (17pp), 2019 April 10 The EHT Collaboration et al. Autónoma de México (DGAPA-UNAM, project IN112417); the European Research Council (ERC) Synergy Grant “BlackHoleCam: Imaging the Event Horizon of Black Holes” (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177; the Gordon and Betty Moore Foundation (grants GBMF-3561, GBMF-5278); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; the Jansky Fellowship program of the National Radio Astronomy Observatory (NRAO); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); JSPS Overseas Research Fellowships; the Key Research Program of Frontier Sciences, Chinese, Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJ-SSW-SYS008); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP18K13594, JP18K03656, JP18H03721, 18K03709, 18H01245, 25120007); the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (105-2112-M-001-025-MY3, 106-2112-M001-011, 106-2119-M-001-027, 107-2119-M-001-017, 107- 2119-M-001-020, and 107-2119-M-110-005); the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC17K0649); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST0705062, AST-0905844, AST-0922984, AST-1126433, AST1140030, DGE-1144085, AST-1207704, AST-1207730, AST1207752, MRI-1228509, OPP-1248097, AST-1310896, AST1312651, AST-1337663, AST-1440254, AST-1555365, AST1715061, AST-1615796, AST-1614868, AST-1716327, OISE1743747, AST-1816420); the Natural Science Foundation of China (grants 11573051, 11633006, 11650110427, 10625314, 11721303, 11725312, 11873028, 11873073, U1531245, 11473010); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (grant 2015-R1D1A1A01056807, the Global PhD Fellowship Grant: NRF-2015H1A2A1033752, and the Korea Research Fellowship Program: NRF-2015H1D3A1066561); the Netherlands Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and Spinoza Prize (SPI 78-409); the New Scientific Frontiers with Precision, Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Technology (DST) of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Economic Development, Job Creation and Trade); the Russian Science Foundation (grant 17-12-01029); the Spanish Ministerio de Economía y Competitividad (grants AYA2015-63939-C2-1-P, AYA2016-80889-P); the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709); the Toray Science Foundation; the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001)); the Italian Ministero dell’Istruzione Università e Ricerca through the grant Progetti Premiali 2012-iALMA (CUP C52I13000140001); the European Unionʼs Horizon 2020 research and innovation programme under grant agreement No 730562 RadioNet; ALMA North America Development Fund; Chandra TM6-17006X
Published: 2019
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10. Performance of the SCUBA-2 dry dilution refrigerator: 4 years of operation at the JCMT

Author: Erik G. Starman, Wayne S. Holland, Simon C. Craig, Dan Bintley, and John Kuroda
Subjects: Physics, business.industry, Liquid helium, Continuous operation, Nuclear engineering, Shields, Cryocooler, Submillimetre astronomy, Dilution, law.invention, Optics, Mauna kea, law, Dilution refrigerator, business
Abstract: Cryogen free or ‘dry’ dilution refrigerators that integrate a cryocooler such as a two stage pulse tube to replace the conventional liquid helium bath and 1K pot, have become a practical alternative for cooling astronomical detectors to mK temperatures and offer many advantages. SCUBA-2, the new submillimetre camera in operation at the JCMT, on the summit of Mauna Kea, Hawaii, was one of the first instruments to use such a fridge design. The dry dilution fridge for SCUBA-2 has now been in service for almost 4 years during commissioning at JCMT. In the most recent astronomical commissioning phase, the dilution fridge was in continuous operation for 10 months with no loss of base temperature or cooling power, cooling the SCUBA-2 detector arrays to below 100mK while maintaining a further 100Kg of enclosure, shields and SQUID amplifiers at 1K. In this paper we review some of the lessons from operating a dry dilution fridge at the JCMT and the necessary changes that have been incorporated. We present the performance of the fridge and discus its role in ensuring the success of SCUBA-2.
Published: 2012
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10. Performance of the SCUBA-2 dry dilution refrigerator: 4 years of operation at the JCMT

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