RT Journal Article T1 Radio imaging of the very-high-energy gamma-ray emission region in the central engine of a radio galaxy A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Contreras González, José Luis A1 Fonseca González, Mª Victoria A1 Miranda Pantoja, José Miguel A1 Nieto, Daniel AB The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole. 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VERITAS: This research is supported by grants from the U.S. Department of Energy, NSF, the Smithsonian Institution, the Natural Sciences and Engineering Research Council of Canada, Science Foundation Ireland, and the STFC in the U.K. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and the collaborating institutions in the construction and operation of the instrument. VLBA: The Very Long Baseline Array is operated by the National Radio Astronomy Observatory, a facility of NSF, operated under cooperative agreement by Associated Universities, Inc. NO ETH NO Polish MniSzW NO Young Investigators Program of the Helmholtz Gemeinschaft NO U.S. Department of Energy NO NSF NO Smithsonian Institution NO Natural Sciences and Engineering Research Council of Canada NO Science Foundation Ireland NO STFC, U.K DS Docta Complutense RD 15 may 2024