相关参考文献
注意：仅列出部分参考文献，下载原文获取全部文献信息。
Article
Astronomy & Astrophysics
Maria J. Rioja et al.
Summary: MM VLBI observations are hindered by limited sensitivity caused by fast tropospheric fluctuations. Applying next-generation frequency phase transfer calibration techniques and simultaneous multi-frequency observations on the ngEHT can bring significant benefits. Simulation studies show that including the 85 GHz band has a transformational impact on the ngEHT array capabilities, greatly improving sensitivity and enabling a wide range of scientific inquiries. We propose a solution for scatter-broadened sources like SgrA* and recommend the inclusion of the 85 GHz band in the ngEHT's receiver design.
Article
Astronomy & Astrophysics
Razieh Emami et al.
Summary: We investigate the physical origin and morphological dependence of twisty patterns of linear polarization in black hole images using general relativistic magnetohydrodynamic simulations. Our results show that the twisty morphology is determined by the magnetic field structure in the emitting region and the dependence on black hole spin is due to changes in the magnetic field geometry caused by frame dragging. Doppler boosting and lensing have subdominant roles, while Faraday rotation only has a significant impact on models with weak magnetic fields. Linear polarization maps can be used as a probe to infer black hole spins based on the underlying magnetic field structure.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Daniel C. M. Palumbo et al.
Summary: The Event Horizon Telescope has provided the first linearly polarized images of the accretion flow around the supermassive black hole M87*, revealing a spiraling polarization pattern that suggests the presence of a magnetically arrested disk. Understanding polarized features in the highly lensed photon ring structure will be crucial for future analysis. Depolarization effects have been observed in the photon ring region, especially in magnetically arrested disk simulations.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Kazunori Akiyama et al.
Summary: This paper provides a first physical interpretation for the Event Horizon Telescope's observations of Sgr A*. By comparing different observations and models, the study identifies promising models while also highlighting their limitations and discussing possible improvements.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
George N. Wong et al.
Summary: The article describes the analysis of reconstructed images of millimeter emission near the supermassive black hole in the center of the M87 galaxy by the Event Horizon Telescope (EHT). The analysis utilized a synthetic black hole image and spectrum library produced through numerical simulations and polarized ray tracing. The article provides a detailed description of the PATOKA pipeline used to generate the simulation library, as well as an overview of the numerical codes iharm, ipole, and igrmonty. The simulated data produced by PATOKA are briefly introduced, and limitations and future directions are discussed.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Astronomy & Astrophysics
Avery E. Broderick et al.
Summary: Through the 2017 Event Horizon Telescope (EHT) observations, we have successfully measured the gravitationally lensed secondary image around M87* and made important inferences regarding parameters such as black hole mass.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Paul Tiede et al.
Summary: General relativity predicts the presence of a photon ring in images of optically thin accretion flows around black holes, providing a pathway to precise measurements of black hole properties and tests of the Kerr metric. VLBI with EHT and ngEHT offer prospects for detecting and measuring the photon ring, but caution must be exercised in interpreting the results of hybrid imaging to avoid false positives.
Article
Astronomy & Astrophysics
Zachary Gelles et al.
Summary: Supermassive black holes can be observed using very long baseline interferometry to directly study the effects of highly curved spacetime. This includes observing a bright photon ring generated from strongly lensed emission. The emission near these black holes is highly variable, and changes in relative brightness of the photon ring can be caused by intrinsic variability. Analyzing toy models and simulations, we observe a characteristic loop in the relationship between relative photon ring brightness and total flux density. Gravitational lensing, Doppler boosting, and magnetic field structure play significant roles in this feature, and its observation in M87* and Sgr A* with the next-generation Event Horizon Telescope is discussed.
Article
Astronomy & Astrophysics
Dominic W. Pesce et al.
Summary: This study presents estimates and empirical evidence for the number of supermassive black holes that can be identified by the next-generation Event Horizon Telescope (ngEHT), as well as the constraints on black hole masses and spins. By constructing a simple geometric model and generating synthetic datasets, the researchers provide insights into the measurement precision of these physical parameters.
Article
Astronomy & Astrophysics
M. Wielgus et al.
Summary: This study reports on the polarized light curves of the Galactic Center supermassive black hole Sagittarius A*, obtained through observations with ALMA. The observations reveal a hot spot embedded in a magnetic field rotating clockwise around the black hole's equator. The simple emission model used in the study captures the overall features of the polarized light curves remarkably well. The study also provides hints of the black hole's spin and estimates the projected on-sky axis of the hot spot's angular momentum.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Will Lockhart et al.
Summary: In this paper, the researchers investigate the robustness of the ring width to changes in the model and find that the main annulus remains narrow even with added model freedom. This provides further evidence in favor of a narrow ring for the true sky appearance of M87*. The techniques introduced in this study may be useful for future observations with a larger and more sensitive array.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Dominic W. Pesce et al.
Summary: This study presents estimates for detecting shadow-resolved supermassive black hole systems using radio interferometers, and demonstrates the potential for accessing a large population of SMBH shadows with improvements in sensitivity. They also predict that next-generation Event Horizon Telescope observing at 345 GHz could access three times as many sources as the current EHT.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Kazunori Akiyama et al.
Summary: The observations by the Event Horizon Telescope revealed important features of polarized emission around the supermassive black hole in M87, including disturbances in the polarization structure and a possible azimuthal linear polarization pattern formed by organized magnetic fields. This suggests insights into the structure of magnetic fields and plasma near the black hole, with implications for understanding the emission mechanisms and properties of the radiating plasma.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
Kazunori Akiyama et al.
Summary: In April 2017, the Event Horizon Telescope observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy, revealing a compact asymmetric ring-like structure originating from synchrotron emission. Only a part of the ring shows significant polarization, with the maximum linear polarization fraction located in the southwest part of the ring.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Multidisciplinary Sciences
Michael D. Johnson et al.
Review
Astronomy & Astrophysics
Maria J. Rioja et al.
ASTRONOMY AND ASTROPHYSICS REVIEW
(2020)
Article
Astronomy & Astrophysics
Daniel C. M. Palumbo et al.
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Elizabeth Himwich et al.
Article
Astronomy & Astrophysics
S. Issaoun et al.
ASTRONOMY & ASTROPHYSICS
(2019)
Article
Astronomy & Astrophysics
Kazunori Akiyama et al.
ASTROPHYSICAL JOURNAL LETTERS
(2019)
Article
Astronomy & Astrophysics
Kazunori Akiyama et al.
ASTROPHYSICAL JOURNAL LETTERS
(2019)
Article
Astronomy & Astrophysics
Samuel E. Gralla et al.
Article
Astronomy & Astrophysics
M. Moscibrodzka et al.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2018)
Article
Astronomy & Astrophysics
Alejandra Jimenez-Rosales et al.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2018)
Article
Astronomy & Astrophysics
Maria J. Rioja et al.
ASTRONOMICAL JOURNAL
(2017)
Review
Astronomy & Astrophysics
Marc Kamionkowski et al.
ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, VOL 54
(2016)
Article
Astronomy & Astrophysics
Monika Moscibrodzka et al.
ASTRONOMY & ASTROPHYSICS
(2016)
Article
Astronomy & Astrophysics
Monika Moscibrodzka et al.
ASTRONOMY & ASTROPHYSICS
(2016)
Article
Astronomy & Astrophysics
Michael D. Johnson
ASTROPHYSICAL JOURNAL
(2016)
Article
Astronomy & Astrophysics
Andrew A. Chael et al.
ASTROPHYSICAL JOURNAL
(2016)
Article
Astronomy & Astrophysics
Michael D. Johnson et al.
ASTROPHYSICAL JOURNAL
(2014)
Article
Astronomy & Astrophysics
Tim Johannsen et al.
ASTROPHYSICAL JOURNAL
(2010)
Article
Astronomy & Astrophysics
CF Gammie et al.
ASTROPHYSICAL JOURNAL
(2003)
