The asymmetry in brightness in the ring can be explained in terms of relativistic beaming of the emission from a plasma rotating close to the speed of light around a black hole. Overall, the observed image is consistent with expectations for the shadow of a Kerr black hole as predicted by general relativity. The emission ring is recovered using different calibration and imaging schemes, with its diameter and width remaining stable over four different observations carried out in different days. We have resolved the central compact radio source as an asymmetric bright emission ring with a diameter of 42 +/- 3 mu as, which is circular and encompasses a central depression in brightness with a flux ratio greater than or similar to 10: 1. This allows us to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.The Event Horizon Telescope Collaboration et al 2019 ApJL 875 L1 Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Physical Origin of the Asymmetric RingĪn open access version is available from UCL Discovery Type:įirst M87 Event Horizon Telescope Results. Analysis of existing EHT polarization data and data taken simultaneously at other wavelengths will soon enable new tests of the GRMHD models, as will future EHT campaigns at 230 and 345 GHz. We briefly consider alternatives to a black hole for the central compact object. At the same time, in those models that produce a sufficiently powerful jet, the latter is powered by extraction of black hole spin energy through mechanisms akin to the Blandford-Znajek process. Models in our library of non-spinning black holes are inconsistent with the observations as they do not produce sufficiently powerful jets. If the black hole spin and M87's large scale jet are aligned, then the black hole spin vector is pointed away from Earth. Overall, the observed image is consistent with expectations for the shadow of a spinning Kerr black hole as predicted by general relativity. The ring radius and ring asymmetry depend on black hole mass and spin, respectively, and both are therefore expected to be stable when observed in future EHT campaigns. We compare the observed visibilities with this library and confirm that the asymmetric ring is consistent with earlier predictions of strong gravitational lensing of synchrotron emission from a hot plasma orbiting near the black hole event horizon. To this end, we construct a large library of models based on general relativistic magnetohydrodynamic (GRMHD) simulations and synthetic images produced by general relativistic ray tracing. Here we consider the physical implications of the asymmetric ring seen in the 2017 EHT data. The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Physical Origin of the Asymmetric Ring_VoR.pdf Younsi_First M87 Event Horizon Telescope Results. First M87 Event Horizon Telescope Results.
0 kommentar(er)
