RT Journal Article T1 Black hole lightning due to particle acceleration at subhorizon scales A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Contreras González, José Luis A1 Fonseca González, María Victoria A1 López Moya, Marcos A1 Miranda Pantoja, José Miguel A1 Satalecka, Konstanzja A1 Scapin, Valeria AB Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here, we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet. PB Amer Assoc Advancement Science SN 0036-8075 YR 2014 FD 2014-11-28 LK https://hdl.handle.net/20.500.14352/33871 UL https://hdl.handle.net/20.500.14352/33871 LA eng NO © The authors. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the Spanish MICINN is gratefully acknowledged. This work was also supported by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant 127740 of the Academy of Finland, by the DFG Cluster of Excellence “Origin and Structure of the Universe”, by the Croatian Science Foundation (HrZZ) Projects 09/176, by the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-ESSMAGIC/2010/0.We thank also the support by DFG WI 1860/10-1. J. S. was supported by ERDF and the Spanish MINECO through FPA2012-39502 and JCI-2011-10019 grants. E. R. was partially supported by the Spanish MINECO projects AYA2009-13036-C02-02 and AYA2012-38491-C02-01 and by the Generalitat Valenciana project PROMETEO/2009/104, as well as by the COST MP0905 action "Black Holes in a Violent Universe". The European VLBI Network is a joint facility of European, Chinese, South African and other radio astronomy institutes funded by their national research councils. The research leading to these results has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under grant agreement No. 283393 (RadioNet3). The MAGIC data is archived in the data center at the Port d´Informació Científica (PIC) in Barcelona. The EVN data are available at the Data Archive at the Joint Institute for VLBI in Europe (JIVE). NO Unión Europea. FP7 NO German BMBF NO German MPG NO Italian INFN NO Swiss National Fund SNF NO Spanish MICINN NO Spanish Consolider-Ingenio 2010 programme NO Academy of Finland NO DFG Cluster of Excellence “Origin and Structure of the Universe” NO Croatian Science Foundation (HrZZ NO University of Rijeka NO DFG Collaborative Research Centers NO Polish MNiSzW NO ERDF NO Spanish MINECO NO Generalitat Valenciana DS Docta Complutense RD 4 abr 2025