![]() ![]() We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. The accompanying papers give a more extensive description of the instrument (EHT Collaboration et al. This stage allowed us to select parameters objectively to use when reconstructing images of M87. In this paper, we present and discuss the first event-horizon-scale images of the supermassive black hole candidate M87 from an EHT VLBI campaign conducted in 2017 April at a wavelength of 1.3 mm. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). To assess the reliability of these results, we implemented a two-stage imaging procedure. ![]() The ring is persistent across four observing nights and shows enhanced brightness in the south. These images show a prominent ring with a diameter of similar to 40 mu as, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. Furthermore, a comparison with the EHT results for the supermassive black hole M87* shows consistency with the predictions of general relativity spanning over three orders of magnitude in central mass.Abstract We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. Our results provide direct evidence for the presence of a supermassive black hole at the center of the Milky Way, and for the first time we connect the predictions from dynamical measurements of stellar orbits on scales of 10 3-10 5 gravitational radii to event-horizon-scale images and variability. M87 ( J2000 12 h 30 m 49 42, J2000 12☂328 04) was observed as a target source on three nights (2017 April 5, 6, and 11). Our model comparisons disfavor scenarios where the black hole is viewed at high inclination (i > 50°), as well as nonspinning black holes and those with retrograde accretion disks. Using a large suite of numerical simulations, we demonstrate that the EHT images of Sgr A* are consistent with the expected appearance of a Kerr black hole with mass ~4 × 10 6 M ⊙, which is inferred to exist at this location based on previous infrared observations of individual stellar orbits, as well as maser proper-motion studies. First M87 Event Horizon Telescope Results. First M87 Event Horizon Telescope Results. The Event Horizon Telescope Collaboration, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Keiichi Asada, Rebecca Azulay, Anne-Kathrin Baczko, David Ball, Mislav Balokovi, John Barrett et al. The Shadow of the Supermassive Black Hole. The ring has modest azimuthal brightness asymmetry and a comparatively dim interior. First M87 Event Horizon Telescope Results. ![]() Here we compare the resolved polarization structure observed by the EHT, along with simultaneous unresolved. This polarized synchrotron radiation probes the structure of magnetic fields and the plasma properties near the black hole. A variety of imaging and modeling analyses all support an image that is dominated by a bright, thick ring with a diameter of 51.8 ± 2.3 μas (68% credible interval). Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. ![]() The EHT data resolve a compact emission region with intrahour variability. These observations were conducted in 2017 using a global interferometric array of eight telescopes operating at a wavelength of λ = 1.3 mm. We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A*), the Galactic center source associated with a supermassive black hole. ![]()
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