The Polarized Image of a Synchrotron Emitting Ring of Gas Orbiting a Black Hole
Ramesh Narayan, Daniel C. M. Palumbo, Michael D. Johnson, Zachary Gelles, Elizabeth Himwich, Dominic O. Chang, Angelo Ricarte, Jason Dexter, Charles F. Gammie, … 展开作者
Ramesh Narayan, Daniel C. M. Palumbo, Michael D. Johnson, Zachary Gelles, Elizabeth Himwich, Dominic O. Chang, Angelo Ricarte, Jason Dexter, Charles F. Gammie, Andrew A. Chael, The Event Horizon Telescope Collaboration, :, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Anne-Kathrin Baczko, David Ball, Mislav Balokovic, John Barrett, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Wilfred Boland, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Do-Young Byun, John E. Carlstrom, Chi-kwan Chan, Shami Chatterjee, Koushik Chatterjee, Ming-Tang Chen, Yongjun Chen, Paul M. Chesler, Ilje Cho, Pierre Christian, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Jordy Davelaar, Mariafelicia DeLaurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Sheperd S. Doeleman, Ralph P. Eatough, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Roberto Garcıa, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Jose L. Gomez, Arturo I. Gomez-Ruiz, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Michael H. Hecht, Ronald Hesper, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jimenez-Rosales, Svetlana Jorstad, 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, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Michael Kramer, Carsten Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Tod R. Lauer, Sang-Sung Lee, Aviad Levis, Yan-Rong Li, Zhiyuan Li, Michael Lindqvist, Rocco Lico, Greg Lindahl, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Pin Lo, Andrei P. Lobanov, Laurent Loinard, Colin Lonsdale, Ru-Sen Lu, Nicholas R. MacDonald, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher Ivan Martı-Vidal, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Monika Moscibrodzka, Cornelia Muller, Gibwa Musoke, Alejandro Mus Mejıas, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Hiroki Okino, Hector Olivares, Gisela N. Ortiz-Leon, Tomoaki Oyama, Feryal Ozel, Jongho Park, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Pietu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Felix M. Potzl, Ben Prather, Jorge A. Preciado-Lopez, Dimitrios Psaltis, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Mel Rose, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sanchez, David Sanchez-Arguelles, Mahito Sasada, Tuomas Savolainen, F. Peter Schloerb, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Kenji Toma, Pablo Torne, Tyler Trent, Efthalia Traianou, Sascha Trippe, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Maciek Wielgus, George N. Wong, Qingwen Wu, Doosoo Yoon, Andre Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Guang-Yao Zhao, Shan-Shan Zhao
Synchrotron radiation from hot gas near a black hole results in a polarized image. The image polarization is determined by effects including the orientation of the magnetic field in the emitting region, relativistic motion of the gas, strong gravitational lensing by the black hole, and parallel transport in the curved spacetime. We explore these effects using a simple model of an axisymmetric, equatorial accretion disk around a Schwarzschild black hole. By using an approximate expression for the null geodesics derived by Beloborodov (2002) and conservation of the Walker-Penrose constant, we provide analytic estimates for the image polarization. We test this model using currently favored general relativistic magnetohydrodynamic simulations of M87*, using ring parameters given by the simulations. For a subset of these with modest Faraday effects, we show that the ring model broadly reproduces the polarimetric image morphology. Our model also predicts the polarization evolution for compact flaring regions, such as those observed from Sgr A* with GRAVITY. With suitably chosen parameters, our simple model can reproduce the EVPA pattern and relative polarized intensity in Event Horizon Telescope images of M87*. Under the physically motivated assumption that the magnetic field trails the fluid velocity, this comparison is consistent with the clockwise rotation inferred from total intensity images.
Hunting Very High-Energy ($>$100 GeV) Emitting High-Synchrotron Peaked Blazars
Tata Institute of Fundamental Research（塔塔基础研究所）；Indian Institute of Technology Indore（印多尔印度理工学院）；Inter-University Centre for Astronomy and Astrophysics（大学间天文与天体物理中心）
Magnetic field estimates from the X-ray synchrotron emitting rims of the 30 Dor C superbubble and the implications for the nature of 30 Dor C's TeV emission
30 Dor C超级气泡因其同步加速器X射线壳而独特，并且是在TeV $γ$射线中检测到的第一个超级气泡，尽管主要的TeV发射机制，即，轻子的还是强子的，还不清楚。我们的目标是使用新的钱德拉观测30 Dor C解决同步加速器壳前所未有的细节，并估计磁（$B$）场在冲击波后区域，TeV之间的一个关键点$γ$射线发射机制。我们提取的径向配置文件在1.5-8千电子伏的范围内，从各个部门周围的同步加速器外壳和拟合这些与投影和点扩散函数卷积postshock体积发射率模型，以确定灯丝宽度。然后我们根据这些宽度计算出了震后的磁场强度。我们发现大多数扇区与我们的冲击后模型很好地拟合，并且确定的$B$ -场值很低，都与$\lesssim 20~μ$ G最佳拟合。三个部门的置信区间上限达到了$\gtrsim 30~μ$ G，尽管这些限制很差。普遍较低的$B$场值表明TeV $γ$射线的起源以轻子为主。我们的休克后模型没有提供足够的适合两个部门。我们发现，一个扇区不能提供足够清晰的径向轮廓，而另一个扇区可以用一个修改过的模型来拟合，在这个模型中，投影轮廓在低于$\sim0.8$乘以壳半径时突然下降，产生了4.8（3.7-11.8）$μ$ G的激波后$B$ -场，这也与轻子TeV $γ$ -射线机制一致。或者，在这些部门所观察到的配置文件可能会导致增强周围的冲击云的相互作用，在以前的工作中建议。在30 …
Testing the Correlations between X-ray Spectral Properties and Polarization for High Synchrotron Peaked Blazars
Science & Technology Institute, Universities Space Research Association（科学与技术学院，美国太空研究协会）；NASA Marshall Space Flight Center（美国国家航空航天局马歇尔太空飞行中心）；Institute of Astrophysics, Foundation for Research and Technology-Hellas（天体物理研究所，希腊研究与技术基金会）；INAF Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；Department of Physics, University of Crete（克里特大学物理系）；INAF Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）
Constraining inhomogeneities and asymmetries in SNe, FBOTs, and other high-energy transients from unresolved radio observations
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México（墨西哥国立自治大学核科学研究所）；Instituto de Astronomía, Universidad Nacional Autónoma de México（墨西哥国立自治大学天文研究所）；Department of Astronomy, University of California, Berkeley（加州大学伯克利分校天文学系）；Berkeley Center for Multi-messenger Research on Astrophysical Transients and Outreach (Multi-RAPTOR), University of California, Berkeley（加州大学伯克利分校多信使天文瞬变现象研究与外展中心（Multi-RAPTOR））；David A. Dunlap Department of Astronomy and Astrophysics, University of Toronto（多伦多大学大卫·邓普克天文与天体物理系）；Dunlap Institute for Astronomy and Astrophysics, University of Toronto（多伦多大学邓普克天文与天体物理研究所）；Racah Institute of Physics, The Hebrew University of Jerusalem（耶路撒冷希伯来大学拉卡物理学研究所）；INAF, Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）
Nonthermal hotspot orbiting the supermassive black hole Sgr A*
Instituto de Astronomía, Universidad Nacional Autónoma de México（墨西哥国立自治大学天文研究所）；Instituto Nacional de Astrofísica, Óptica y Electrónica（墨西哥国家天文学、光学和电子学研究所）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交通大学李政道研究所）；School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）
Interacting Cosmic Rays with Molecular Clouds: A Bremsstrahlung Origin of Diffuse High Energy Emission from the Inner 2deg by 1deg of the Galactic Center
Multi-Band Optical Variability Characteristics of the $γ$-ray emitting blazar 1ES 0647+250 during its 2020 flare
Bharathiar University（巴腊提亚尔大学）；Indian Institute of Astrophysics（印度天体物理研究所）；SGT University（SGT大学）；Polish Academy of Sciences（波兰科学院）；Government Arts and Science College, Sivakasi（西瓦卡西市立文理学院）；Government High School, Sirumalaipudur（锡鲁马拉伊杜尔国立高中）
