Auxiliary Information

Online material related to the H.E.S.S. data published in

IceCube Collaboration et al., Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A. Science 361

H.E.S.S. performed a first set of follow-up observations towards the direction of the blazar TXS 0506+056 during the night of 22 September, 2017 (ATEL #10787). The observations started about 4h after the detection of a high-energy neutrino by IceCube (GCN 21916). A second set of observations was acquired during the nights of 27 September, 2017 and 28 September, 2017. In total 3.25 hours of high-quality observations including the central large telescope (CT5) were obtained at zenith angles ranging from 31 deg to 46 deg.

This dataset was analyzed in monoscopic mode using the Model Analysis (M. de Naurois, L. Rolland, Astropart. Physics 32, 231 (2009)) with loose cuts. No gamma-ray emission at a significant level was detected. The resulting maps of excess gamma rays and their significance are given below.

TXS0506+056 excess map: [FITS] [PNG]
TXS0506+056 significance map: [FITS] [PNG]