3HSP J095507.9+355101: A flaring extreme blazar coincident in space and time with IceCube-200107A P. Giommi, P. Padovani, F. Oikonomou, T. Glauch, S. Paiano and E. Resconi A&A, 640 (2020) L4 Published online: 30 July 2020 DOI: 10.1051/0004-6361/202038423