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1. Fast single-dish scans of the Sun using ALMA

Author

Phillips, Neil, Hills, Richard, Bastian, Tim, Hudson, Hugh, Marson, Ralph, and Wedemeyer, Sven

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

We have implemented control and data-taking software that makes it possible to scan the beams of individual ALMA antennas to perform quite complex patterns while recording the signals at high rates. We conducted test observations of the Sun in September and December, 2014. The data returned have excellent quality; in particular they allow us to characterize the noise and signal fluctuations present in this kind of observation. The fast-scan experiments included both Lissajous patterns covering rectangular areas, and double-circle patterns of the whole disk of the Sun and smaller repeated maps of specific disk-shaped targets. With the latter we find that we can achieve roughly Nyquist sampling of the Band~6 (230~GHz) beam in 60~s over a region 300$"$ in diameter. These maps show a peak-to-peak brightness-temperature range of up to 1000~K, while the time-series variability at any given point appears to be of order 0.5 percent RMS over times of a few minutes. We thus expect to be able to separate the noise contributions due to transparency fluctuations from variations in the Sun itself. Such timeseries have many advantages, in spite of the non-interferometric observations. In particular such data should make it possible to observe microflares in active regions and nanoflares in any part of the solar disk and low corona., Comment: Presented at "Revolution in Astronomy with ALMA - the third year -", Tokyo, December 2014

Published
2015

2. Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution

Author

Kim, Jae-Young, Krichbaum, Thomas P., Broderick, Avery E., Wielgus, Maciek, Blackburn, Lindy, Gomez, Jose 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., Ozel, Feryal, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, 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., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Palumbo, Daniel C. M., Park, Jongho, Patel, Nimesh, Pen, Ue-Li, Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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., Sanchez, Salvador, Sanchez-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, Andre, 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-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, 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, Gomez-Ruiz, Arturo, I, Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, 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, Montana, 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, Parsons, Harriet, Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. 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, Kim, Jae-Young, Krichbaum, Thomas P., Broderick, Avery E., Wielgus, Maciek, Blackburn, Lindy, Gomez, Jose 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., Ozel, Feryal, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, 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., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Palumbo, Daniel C. M., Park, Jongho, Patel, Nimesh, Pen, Ue-Li, Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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., Sanchez, Salvador, Sanchez-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, Andre, 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-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, 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, Gomez-Ruiz, Arturo, I, Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, 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, Montana, 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, Parsons, Harriet, Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. 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, and Ziurys, Lucy

Abstract

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 1.3 mm (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 gamma -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 (ALMA), at an angular resolution of similar to 20 mu as (at a redshift of z=0.536 this corresponds to similar to 0.13 pc similar to 1700 Schwarzschild radii with a black hole mass M-BH=8x10(8) M-circle dot). 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 different 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 similar to 15 c and similar to 20 c (similar to 1.3 and similar to 1.7 mu as day(-1), respectively), which more strongly supports the scenario of traveling shocks or instabilities in a be

Published
2020

3. First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole

Author

Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Blackburn, Lindy, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broderick, Avery E., Broguiere, Dominique, Bronzwaer, Thomas, Byun, Do-Young, Carlstrom, John E., Chael, Andrew, Chan, Chi-kwan, 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, Freeman, William T., Friberg, Per, Fromm, Christian M., Gomez, Jose L., Galison, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, Johnson, Michael D., Jorstad, Svetlana, Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Jae-Young, Kim, Junhan, Kim, Jongsoo, Kino, Motoki, Koay, Jun Yi, Koch, Patrick M., Koyama, Shoko, Kramer, Michael, Kramer, Carsten, Krichbaum, Thomas P., Kuo, Cheng-Yu, Lauer, Tod R., Lee, Sang-Sung, Li, Yan-Rong, Li, Zhiyuan, Lindqvist, Michael, 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., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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., Sanchez, Salvador, Sanchez-Arguelles, David, Sasada, Mahito, Savolainen, Tuomas, 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, Trippe, Sascha, Tsuda, Shuichiro, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Wagner, Jan, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wielgus, Maciek, Wong, George N., Wu, Qingwen, Young, Ken, Young, Andre, 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-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, Coulson, Iain M., Crawford, Thomas M., Crowley, Joseph, David, John, 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, Gomez-Ruiz, Arturo I., Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, Jiang, Homin, 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, Montana, 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, Parsons, Harriet, Paine, Scott N., Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. K., Srinivasan, Ranjani, Stahm, William, Stark, Anthony 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, Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Blackburn, Lindy, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broderick, Avery E., Broguiere, Dominique, Bronzwaer, Thomas, Byun, Do-Young, Carlstrom, John E., Chael, Andrew, Chan, Chi-kwan, 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, Freeman, William T., Friberg, Per, Fromm, Christian M., Gomez, Jose L., Galison, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, Johnson, Michael D., Jorstad, Svetlana, Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Jae-Young, Kim, Junhan, Kim, Jongsoo, Kino, Motoki, Koay, Jun Yi, Koch, Patrick M., Koyama, Shoko, Kramer, Michael, Kramer, Carsten, Krichbaum, Thomas P., Kuo, Cheng-Yu, Lauer, Tod R., Lee, Sang-Sung, Li, Yan-Rong, Li, Zhiyuan, Lindqvist, Michael, 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., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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., Sanchez, Salvador, Sanchez-Arguelles, David, Sasada, Mahito, Savolainen, Tuomas, 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, Trippe, Sascha, Tsuda, Shuichiro, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Wagner, Jan, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wielgus, Maciek, Wong, George N., Wu, Qingwen, Young, Ken, Young, Andre, 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-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, Coulson, Iain M., Crawford, Thomas M., Crowley, Joseph, David, John, 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, Gomez-Ruiz, Arturo I., Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, Jiang, Homin, 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, Montana, 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, Parsons, Harriet, Paine, Scott N., Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. K., Srinivasan, Ranjani, Stahm, William, Stark, Anthony 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, and Ziurys, Lucy

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 mu as, which is circular and encompasses a central depression in brightness with a flux ratio greater than or similar to 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) x 10(9) M-circle dot. Our radio-wave 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.

Published
2019

14. LETTERS TO THE EDITOR.

Author

Donovan, Tim, Marson, Ralph, Smyth, M. P., Garza, Leonore, and Aldrich, Kevin

Subjects
BISHOPS, CHRISTIANITY, RACIAL differences, CATHOLICS
Published
2015

15. LETTERS TO THE EDITOR.

Author

Bradshaw, A., Marson, Ralph A., Lipke, Arleen M., K., Jennifer, M. P. D., and MiLi

Subjects
FAITH, CATHOLIC schools, ABORTION
Abstract

Several letters to the editor are presented in response to articles in previous issues including "Links in a chain," in the January 26m 2014 issue, "Bright ideas" in the January 26, 2014 issue, and "Growing up pro-life" in the January 19, 2014 issue.

Published
2014

16. LETTERS TO THE EDITOR.

Author

Schroeder, Rita, Marson, Ralph A., Kurt, James, Brady, William J., and Sharbaugh, Jim

Subjects
PURGATORY, FAITH
Abstract

Several letters to the editor are presented in response to articles in previous issues including "Did you hear?: Gossip builds walls between us and others" in the September 8, 2013 issue, "9 truths about purgatory" in the September 29, 2013 issue, and "Angelic helpers" in the October 13, 2013 issue.

Published
2013

17. LETTERS TO THE EDITOR.

Author

Chude, Jim, Taub, David J., Donovan, Tim, Lutz, Anthony D., Becker, James, and Marson, Ralph A.

Subjects
LETTERS to the editor, GOVERNMENT aid, RELIGIOUS institutions, SPIRITUALITY
Published
2013

18. LETTERS TO THE EDITOR.

Author

Chude, Jim, Taube, David J., Donovan, Tim, Lutz, Anthony D., Becker, James, and Marson, Ralph A.

Subjects
LETTERS to the editor, UNITED States presidential election, 2012
Abstract

A letter to the editor is presented in response to the column that the November 2012 U.S. elections was split along aid to the poor versus pro-life issues.

Published
2012

19. LETTERS TO THE EDITOR.

Author

Cullinan, Tom, Marson, Ralph A., Byrne, Shirley, Hagen, Earl, and Stein, Dorothy

Subjects
LETTERS to the editor, CATHOLICS, GOD
Abstract

Several letters to the editor are presented in response to articles in previous issues including "Pope charms, challenges secular Great Britain," in the October 3, 2010 issue, "Is the tea party at odds with Catholic teaching," in the October 17, 2010 issue and "The abuse crisis attracting God's awful avenging warriors," in the October 31, 2010 issue.

Published
2010

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