相关论文: First M87 Event Horizon Telescope Results. II. Arr…
General relativity predicts that images of optically thin accretion flows around black holes should generically have a ``photon ring,'' composed of a series of increasingly sharp subrings that correspond to increasingly strongly lensed…
The Shanghai Astronomical Observatory (SHAO) of the Chinese Academy of Sciences (CAS) is studying a space VLBI (Very Long Baseline Interferometer) program. The ultimate objective of the program is to image the immediate vicinity of the…
In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source…
The proposed next generation Event Horizon Telescope (ngEHT) concept envisions the imaging of various astronomical sources on scales of microarcseconds in unprecedented detail with at least two orders of magnitude improvement in the image…
We report on new developments in VLBI, with emphasis on experiments performed at the highest frequencies possible to date (so called mm-VLBI). We have observed the nucleus of M 87 (Virgo A) with global VLBI at 3 mm. We show a new image of…
General Relativity predicts that the emission close to a black hole must be lensed by its strong gravitational field, illuminating the last photon orbit. This results in a dark circular area known as the black hole 'shadow'. The Event…
The Event Horizon Telescope (EHT) is providing unprecedented high-resolution images of supermassive black holes. These images are fundamentally related to properties of the luminous accretion disks, since black holes themselves produce no…
The Black Hole Explorer (BHEX) will be the first sub-mm wavelength Space Very-Long-Baseline Interferometry (VLBI) mission. It targets astronomical imaging with the highest ever spatial resolution to enable detection of the photon ring of a…
Operating 1.5 million km from Earth at the Sun-Earth L2 Lagrange point, the Origins Space Telescope equipped with a slightly modified version of its HERO heterodyne instrument could function as a uniquely valuable node in a VLBI network.…
Advances in VLBI instrumentation now allow wideband recording that significantly increases the sensitivity of short wavelength VLBI observations. Observations of the super-massive black hole candidate at the center of the Milky Way, SgrA*,…
The Event Horizon Telescope Collaboration (EHTC) has presented first - dynamic-range limited - images of the black hole shadows in M87 and Sgr A*. The next generation Event Horizon Telescope (ngEHT) will provide higher sensitivity and…
Very-long-baseline interferometry (VLBI) observations of active galactic nuclei at millimeter wavelengths have the power to reveal the launching and initial collimation region of extragalactic radio jets, down to $10-100$ gravitational…
The observation of the shadow of the supermassive black hole M87$^{*}$ by the Event Horizon Telescope (EHT) is sensitive to the spacetime geometry near the circular photon orbit and beyond, and it thus has the potential to test general…
The next-generation Event Horizon Telescope (ngEHT) will be a significant enhancement of the Event Horizon Telescope (EHT) array, with $\sim 10$ new antennas and instrumental upgrades of existing antennas. The increased $uv$-coverage,…
The fast developments of radio astronomy open a new window to explore the properties of Dark Matter (DM). The recent direct imaging of the supermassive black hole (SMBH) at the center of M87 radio galaxy by the Event Horizon Telescope (EHT)…
We report our independent image reconstruction of the M 87 from the public data of the Event Horizon Telescope Collaborators (EHTC). Our result is different from the image published by the EHTC. Our analysis shows that (a) the structure at…
Global VLBI imaging at millimeter and sub-millimeter wavelength overcomes the opacity barrier of synchrotron self-absorption in AGN and opens the direct view into sub-pc scale regions not accessible before. Since AGN variability is more…
Photon rings near the edge of a black hole shadow is supposed to be a unique tool to validate general relativity and provide reliable measurements of principal black hole parameters: spin and mass. Such measurements are possible though only…
In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly…
Using the Event Horizon Telescope (EHT), the gravitationally lensed rings around the supermassive black holes (SMBHs) in Messier 87 (M87) and Sagittarius A* (Sgr A*) have now been successfully imaged at a resolution under 10 gravitational…