Article
Astronomy & Astrophysics
Yong-Jie Chen, Jun-Rong Liu, Shuo Zhai, Zhu-Heng Yao, Yan-Rong Li, Pu Du, Chen Hu, Wei-Jian Guo, Ming Xiao, Yu-Yang Songsheng, Jian-Min Wang
Summary: In this study, optical and mid-infrared light curves were compiled to measure the time lags between different wavelengths and constrain the relationships between torus sizes and AGN properties. The results show that the torus sizes are correlated with black hole mass and accretion rate. This study is important for understanding the formation and evolution of AGNs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Tong Bao, Zhiyuan Li
Summary: Recent X-ray observations have found growing evidence of quasi-periodic oscillation (QPO) in the light curve of active galactic nuclei (AGNs), providing useful insight into black hole physics. This study systematically searched for X-ray QPOs among approximately 1000 AGNs in the Chandra Deep Field South (CDF-S), but no statistically significant periodic signals were detected. Extensive simulations suggest that the non-detection may be due to the moderate sensitivity of the CDF-S data in QPO detection. However, two candidate short-lived QPOs were found in a subset of observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Yu-Ching Chen, Xin Liu, Joseph Lazio, Peter Breiding, Sarah Burke-Spolaor, Hsiang-Chih Hwang, Yue Shen, Nadia L. Zakamska
Summary: Dual and off-nucleus active supermassive black holes are common in the universe, and their identification at parsec scales has been a challenge. Using VLBA, we conducted a systematic study and identified 8 candidate dual or off-nucleus quasars.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
A. Georgakakis, I Papadakis, M. Paolillo
Summary: An empirical model is proposed to link the demographics of active galactic nuclei (AGN) to their X-ray variability properties, based on observational measurements of AGN incidence in galaxies. The study finds that the amplitude of the power spectrum density (PSD) depends on the physical properties of accretion events, and current observational measurements of ensemble excess variance are consistent with the black hole mass versus stellar mass relation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Kirk Long, Jason Dexter, Yixian Cao, Ric Davies, Frank Eisenhauer, Dieter Lutz, Daryl Santos, Jinyi Shangguan, Taro Shimizu, Eckhard Sturm
Summary: Quasars exhibit significant atomic emission-line broadening, crucial for estimating the mass of the central supermassive black hole based on its radial distance. This estimation relies on the structure and kinematics of the broad-line region, often modeled as a collection of discrete emitting clouds. In this study, a kinematic disk-wind model of optically thick line emission from a thin accretion disk is proposed and tested using GRAVITY data and previous cloud modeling results. Although the model fits well with the data from quasar 3C 273, it is disfavored due to the inconsistency with observations of the radio jet orientation.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
A. Ferre-Mateu, M. Mezcua, R. S. Barrows
Summary: A study on the active BH activity in low-mass compact galaxies reveals that some compact elliptical galaxies host AGN, and these galaxies tend to be overmassive in the BH-galaxy scaling relations, supporting a stripping origin for the majority of these objects.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Hiromichi Tagawa, Bence Kocsis, Zoltan Haiman, Imre Bartos, Kazuyuki Omukai, Johan Samsing
Summary: The recently discovered gravitational wave sources GW190521 and GW190814 show evidence of black hole mergers that deviate from traditional isolated stellar evolution models, indicating the possibility of hierarchical mergers in active galactic nuclei (AGNs) disks. The properties of the observed events are consistent with theoretical models of mergers in AGN disks, including high BH masses in GW190521 and low mass gap mergers in GW190814. These findings suggest that mergers in AGN disks may play a significant role in the formation of gravitational wave sources.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Jie Li, Zhongxiang Wang, Dong Zheng
Summary: We report the discovery of optical periodic modulation in two Active Galactic Nuclei (AGN) and one candidate AGN, based on archival optical data and mid-infrared light-curve data analysis. The optical periodicities of sources J0122 + 1032, J1007 + 1248 (or PG 1004 + 1248), and J2131 - 1127 were found to be 2169.7, 2103.1, and 1462.6 days, respectively. The analysis of optical spectra suggests that the first source is likely a blazar, the second source is a type 1 Seyfert galaxy, and the third source is likely an AGN. Additionally, the study discusses the possible origin of the optical modulation and interesting features within the supermassive black hole binary (SMBHB) scenario.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jongho Park, Do-Young Byun, Keiichi Asada, Youngjoo Yun
Summary: GPCAL is an automated pipeline for instrumental polarization calibration in VLBI data, aiming to achieve high calibration accuracy by fitting the instrumental polarization model to data from multiple calibrator sources simultaneously. It allows for more accurate linear polarization models of calibrators compared to conventional methods, which assume similar linear polarization and total intensity structures.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Y. Yang, I. Bartos, G. Fragione, Z. Haiman, M. Kowalski, S. Marka, R. Perna, H. Tagawa
Summary: Micro tidal disruption events (micro-TDEs) in active galactic nuclei (AGNs) serve as a useful probe of stellar interaction with the AGN disk. The observed rate of micro-TDEs appears to be lower than estimated.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Amy Secunda, Betsy Hernandez, Jeremy Goodman, Nathan W. C. Leigh, Barry McKernan, K. E. Saavik Ford, Jose I. Adorno
Summary: This study analyzed the impact of retrograde orbiters (ROs) in active galactic nucleus (AGN) disks on the formation and mergers of stellar-mass black hole binaries (BBHs), finding that their rapid evolution could lead to extreme mass ratio inspirals detectable by the Laser Interferometer Space Antenna, with collision rates dependent on the volume of the inner radiation-pressure-dominated region.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
Dominik Gronkiewicz, Agata Rozanska, Pierre-Olivier Petrucci, Renaud Belmont
Summary: This paper provides a plausible explanation for the soft X-ray excess in active galactic nuclei (AGNs) with warm coronas. The study used a self-consistent model to investigate an accretion disk with an optically thick corona, where the gas is heated by magneto-rotational instability dynamo (MRI) and simultaneously cooled by radiation. The research aims to determine the parameters of a warm corona in AGNs and highlight the role of thermal instability (TI) as a constraint for warm, optically thick X-ray coronas.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Gaoxiang Jin, Y. Sophia Dai, Hsi-An Pan, Lihwai Lin, Cheng Li, Bau-Ching Hsieh, Shiyin Shen, Fang-Ting Yuan, Shuai Feng, Cheng Cheng, Hai Xu, Jia-Sheng Huang, Kai Zhang
Summary: The study, based on the MaNGA survey, suggests that the role of AGNs during galaxy interactions is still debated. However, there is no significant difference in the evolution of AGNs along the merger sequence compared to isolated galaxies. A higher fraction of passive galaxies in galaxy pairs was observed, indicating the importance of environmental dependence.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Yongjung Kim, Myungshin Im
Summary: Research indicates that the observed evolution of UV QLF at high redshift can be explained by a pure density evolution model, suggesting that the QLF evolution at high redshift can be understood within the framework of halo mass function evolution. The model also reveals the existence of a hidden population of faint AGNs.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
Y. Diaz, L. Hernandez-Garcia, P. Arevalo, E. Lopez-Navas, C. Ricci, M. Koss, O. Gonzalez-Martin, M. Balokovic, N. Osorio-Clavijo, J. A. Garcia, A. Malizia
Summary: This study investigates the reflector configuration in low-luminosity AGN by combining data from XMM-Newton+ NuSTAR + Swift. The results suggest that LLAGN have a smaller column density in the torus reflector compared to high-luminosity AGN. The study also confirms a relationship between Gamma and the accretion rate in LLAGN with a smaller scatter.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Nibedita Kalita, Yuhai Yuan, Minfeng Gu, Junhui Fan, Yosuke Mizuno, Peng Jiang, Alok C. Gupta, Hongyan Zhou, Xiang Pan, Anton A. Strigachev, Rumen S. Bachev, Lang Cui
Summary: BL Lacertae underwent a series of historical high flux activity from August 2020 to November 2021, spanning the optical to VHE gamma-rays. The first historical maxima outburst event during October-November in the g, r, and i bands was observed using the 1.26 m telescope at the Xinglong Observatory, China. Intranight variations with amplitude up to 30% and a few tens of minutes variability timescale were detected, indicating the presence of jet mini-structures.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Ryo Imazawa, Mahito Sasada, Natsuko Hazama, Yasushi Fukazawa, Koji S. Kawabata, Tatsuya Nakaoka, Hiroshi Akitaya, Thomas Bohn, Anjasha Gangopadhyay
Summary: We obtained simultaneous and continuous photo-polarization observations of the blazar BL Lacertae in optical and near-infrared (NIR) bands, which revealed microvariability on short timescales and significant differences in polarization properties between the two bands, suggesting the presence of complicated emission regions.
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
(2023)
Article
Astronomy & Astrophysics
C. J. Clark, M. Kerr, E. D. Barr, B. Bhattacharyya, R. P. Breton, P. Bruel, F. Camilo, W. Chen, I. Cognard, H. T. Cromartie, J. Deneva, V. S. Dhillon, L. Guillemot, M. R. Kennedy, M. Kramer, A. G. Lyne, D. Mata Sanchez, L. Nieder, C. Phillips, S. M. Ransom, P. S. Ray, M. S. E. Roberts, J. Roy, D. A. Smith, R. Spiewak, B. W. Stappers, S. Tabassum, G. Theureau, G. Voisin
Summary: A few missing photons in Fermi Gamma-ray Space Telescope observations provide reliable neutron star mass measurements in eclipsing millisecond pulsar binaries, ruling out ultramassive pulsars in the original Black Widow system. Spectroscopy of bright companions in black widow systems can determine their radial velocities and provide inclination-dependent pulsar mass estimates. Gamma-ray eclipses in spider systems, discovered through observations from the Fermi Large Area Telescope, strictly limit the binary inclination angle and provide robust, model-independent pulsar mass constraints.
Article
Astronomy & Astrophysics
Wei Yu, John W. W. Romein, L. Jonathan Dursi, Ru-Sen Lu, Adrian Pope, Gareth Callanan, Dominic W. W. Pesce, Lindy Blackburn, Bruce Merry, Ranjani Srinivasan, Jongsoo Kim, Jonathan Weintroub
Summary: The next-generation Event Horizon Telescope (ngEHT) achieves ultra-low angular resolution by using Very Long Baseline Interferometry (VLBI) at a wavelength of 1 mm. This paper proposes using Tensor Core Graphics Processing Units (TC GPU) as the primary digital signal processing engine and explores its opportunities and challenges.
Article
Astronomy & Astrophysics
Jens Kauffmann, Ganesh Rajagopalan, Kazunori Akiyama, Vincent Fish, Colin Lonsdale, Lynn D. Matthews, Thushara G. S. Pillai
Summary: The Haystack Telescope is a 37 m diameter antenna capable of millimeter-wave observations. It serves as a radar sensor for space situational awareness and is used for research by MIT Haystack Observatory. Ongoing testing is preparing for its inclusion in the Event Horizon Telescope array and its use as a single-dish research telescope. Its addition would substantially improve the image quality of the EHT array.
Article
Astronomy & Astrophysics
Tomohisa Kawashima, Ken Ohsuga, Hiroyuki R. Takahashi
Summary: We introduce a radiative transfer code RAIKOU for multiwavelength studies of spectra and images, including the black hole shadows around Kerr black holes. The code incorporates important radiative processes in hot plasmas around black holes such as (cyclo-)synchrotron, bremsstrahlung emission/absorption, and Compton/inverse-Compton scattering. Two calculation algorithms, the observer-to-emitter ray-tracing algorithm and the emitter-to-observer Monte Carlo algorithm, are implemented for efficient computation of images and broadband spectra with/without Compton effects. The code is applicable to accretion flows around Kerr black holes with relativistic jets and winds/coronae of various mass accretion rates.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Svetlana Jorstad, Maciek Wielgus, Rocco Lico, Sara Issaoun, Avery E. Broderick, Dominic W. Pesce, Jun Liu, Guang-Yao Zhao, Thomas P. Krichbaum, Lindy Blackburn, Chi-kwan Chan, Michael Janssen, Venkatessh Ramakrishnan, Kazunori Akiyama, Antxon Alberdi, Juan Carlos Algaba, Katherine L. Bouman, Ilje Cho, Antonio Fuentes, Jose L. Gomez, Mark Gurwell, Michael D. Johnson, Jae-Young Kim, Ru-Sen Lu, Ivan Marti-Vidal, Monika Moscibrodzka, Felix M. Poetzl, Efthalia Traianou, Ilse van Bemmel, Walter Alef, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Balokovic, John Barrett, Michi Baubock, Bradford A. Benson, Dan Bintley, Raymond Blundell, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Do-Young Byun, John E. Carlstrom, Chiara Ceccobello, Andrew Chael, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, 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, Peter Galison, Charles F. Gammie, Roberto Garcia, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Arturo I. Gomez-Ruiz, Minfeng Gu, 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, David J. James, Buell T. Jannuzi, Britton Jeter, Wu Jiang, Alejandra Jimenez-Rosales, Abhishek V. Joshi, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Shoko Koyama, Carsten Kramer, Michael Kramer, Cheng-Yu Kuo, Noemi La Bella, Tod R. Lauer, Daeyoung Lee, Sang-Sung Lee, Po Kin Leung, Aviad Levis, Zhiyuan Li, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Nicholas R. MacDonald, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Daniel Michalik, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Cornelia Mueller, 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, Hector Olivares, Gisela N. Ortiz-Leon, Tomoaki Oyama, Feryal Ozel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Vincent Pietu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Ben Prather, Jorge A. Preciado-Lopez, Dimitrios Psaltis, Hung-Yi Pu, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Angelo Ricarte, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Canizales, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sanchez, David Sanchez-Arguelles, Miguel Sanchez-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, Tyler Trent, Sascha Trippe, Matthew Turk, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Qingwen Wu, Paul Yamaguchi, Doosoo Yoon, Andre Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Shan-Shan Zhao
Summary: This study reports on the observations of quasar NRAO 530 with the Event Horizon Telescope, which produced the first image of the most distant object observed by EHT to date. The image shows a bright feature with linear polarization at the core of the quasar, revealing a helical magnetic field structure in the jet.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Ben S. Prather, Jason Dexter, Monika Moscibrodzka, Hung-Yi Pu, Thomas Bronzwaer, Jordy Davelaar, Ziri Younsi, Charles F. Gammie, Roman Gold, George N. Wong, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Balokovic, John Barrett, Michi A. Bauboeck, Bradford Benson, Dan Bintley, Lindy Blackburn, Raymond L. Blundell, Katherine C. Bouman, Geoffrey Bower, Hope Boyce, Michael D. Bremer, Christiaan Brinkerink, Roger Brissenden, Silke E. Britzen, Avery Broderick, Dominique Broguiere, Sandra Bustamante, Do-Young E. Byun, John Carlstrom, Chiara Ceccobello, Andrew Chael, Chi-kwan O. Chan, Dominic Chang, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre S. Christian, Nicholas E. Conroy, John M. Conway, James M. Cordes, Thomas B. Crawford, Geoffrey Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Vedant S. Dhruv, Sheperd Doeleman, Sean A. Dougal, Sergio P. Dzib, Ralph Eatough, Razieh Emami, Heino Falcke, Joseph L. Farah, Vincent Fish, Ed Fomalont, H. Alyson Ford, Raquel T. Fraga-Encinas, William Freeman, Per M. Friberg, Christian Fromm, Antonio Fuentes, Peter Galison, Roberto Garcia, Olivier Gentaz, Boris Georgiev, Ciriaco I. Goddi, Arturo Gomez-Ruiz, Jose L. Gomez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Kari H. Haworth, Michael Hecht, Ronald Hesper, Dirk C. Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei H. Huang, David Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara J. Issaoun, David T. James, Buell Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra D. Jimenez-Rosales, Michael Johnson, Svetlana V. Jorstad, Abhishek Joshi, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa K. Kawashima, Garrett Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Shoko Koyama, Carsten Kramer, Michael P. Kramer, Thomas Krichbaum, Cheng-Yu Kuo, Noemi R. La Bella, Tod 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 P. Lo, Andrei Lobanov, Laurent J. Loinard, Colin Lonsdale, Ru-Sen R. Lu, Nicholas MacDonald, Jirong Mao, Nicola Marchili, Sera P. Markoff, Daniel P. Marrone, Alan Marscher, Ivan Marti-Vidal, Satoki D. Matsushita, Lynn Matthews, Lia M. Medeiros, Karl Menten, Daniel Michalik, Izumi Mizuno, Yosuke M. Mizuno, James Moran, Kotaro Moriyama, Cornelia Mueller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Andrew Nadolski, Hiroshi M. Nagai, Neil Nagar, Masanori Nakamura, Ramesh Narayan, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis A. Noutsos, Michael Nowak, Junghwan Oh, Hiroki Okino, Hector N. Olivares, Gisela Ortiz-Leon, Tomoaki Oyama, Feryal oezel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li W. Pen, Dominic Pesce, Vincent Pietu, Richard Plambeck, Aleksandar PopStefanija, Oliver M. Porth, Felix A. Poetzl, Jorge Preciado-Lopez, Dimitrios Psaltis, Venkatessh Ramakrishnan, Ramprasad G. Rao, Mark W. Rawlings, Alexander Raymond, Luciano Rezzolla, Angelo Ricarte, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Canizales, Arash Roshanineshat, Helge L. Rottmann, Alan Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sanchez, David Sanchez-Argueelles, Miguel Sanchez-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 J. Tazaki, Alexandra Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan R. van Langevelde, Daniel van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Maciek Wielgus, Kaj Wiik, Gunther F. Witzel, Michael Wondrak, Qingwen Wu, Paul Yamaguchi, Aristomenis Yfantis, Doosoo Yoon, Andre Young, Ken Young, Wei Yu, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao
Summary: Interpretation of resolved polarized images of black holes by the EHT relies on predicting the polarized emission observable by Earth-based instruments for a specific black hole accretion model. GRRT codes used within the EHT Collaboration are evaluated for accuracy and consistency in producing test images, demonstrating high consistency in various methods and implementations of radiative transfer calculations. The comparison shows similar images with a pixel-wise normalized mean squared error (NMSE) of 0.012 for an analytic accretion model, and NMSEs of 0.02, 0.04, 0.04, and 0.12 in Stokes I, Q, U, and V for a cell-based magnetohydrodynamic simulation snapshot. The agreement between the image metrics and published EHT results is better than measurement uncertainties.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Mao Yuan, Weiwei Zhu, Michael Kramer, Bo Peng, Jiguang Lu, Renxin Xu, Lijing Shao, Hong-Guang Wang, Lingqi Meng, Jiarui Niu, Rushuang Zhao, Chenchen Miao, Xueli Miao, Mengyao Xue, Yi Feng, Pei Wang, Di Li, Chengming Zhang, David J. Champion, Emmanuel Fonseca, Huanchen Hu, Jumei Yao, Paulo C. C. Freire, Yanjun Guo
Summary: We have identified three new weak pulse components in two known pulsars, PSR J0304+1932 and PSR J1518+4904. These components are emitted at a midpoint between the main emission beam and the interpulse beam, and exhibit a certain degree of separation from the main pulse peak. Our analysis also reveals correlations between these weak pulses and their main pulses, suggesting that they originate from the same pole. Additionally, our estimation of the emission altitude suggests that these pulse components are high-altitude emissions, challenging current pulsar emission models.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
V. S. Beskin, F. A. Kniazev, K. Chatterjee
Summary: The present work focuses on analyzing the internal structure of relativistic jets with zero plasma flow velocity along the jet axis. It is found that despite the difference in problem formulation at the axis, the key properties of the internal structure of such relativistic jets remain the same as for those with non-zero velocity. In both cases, a dense core with a radius close to the size of the light cylinder appears near the axis under sufficiently low ambient pressure.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)