Authors: J.-Y. Kim, T. P. Krichbaum, Ru-Sen Lu, M. Bremer, A. Zensus, R. C. Walker, the M87 collaboration
Journal: Transactions of IAA RAS vol. 40
Keywords: Galaxies: active, Galaxies: individual (M87), Galaxies: jets, Techniques: interferometric
M87 is one of the nearest AGN with a pronounced jet and hosting a central supermassive black hole (SMBH). The close distance to the source and the large mass of the central SMBH make M87 an ideal target to investigate various aspects on the formation and evolution of relativistic jets on the smallest spatial scale. Here, we present preliminary results from our ongoing study on M87 based on global VLBI observations at 86 GHz. GMVA observations in May 2015 resulted in a new image showing a complex jet morphology on sub-mas scales. Stacking available VLBI images obtained at different epochs reveals a persistent shape of the jet base. This allows us to trace the jet collimation from 100Rsch down to ∼ 50Rsch.