Observations of IceCube HESE track directions with the MAGIC telescopes

The MAGIC telescopes are strongly involved in several multimessenger programs. One of them are follow-up observations of astrophysical neutrino events, to search for hadronic γ-ray emission from the neutrino direction and identify potential neutrino sources. In 2013 the IceCube collaboration reported the first detection of astrophysical neutrinos and up to now 55 events, which interact inside the IceCube detector active volume, dubbed High Energy Starting Events (HESE), have been reported. These include 13 track-like events, caused usually by muon neutrino charge current interactions. The track-like events (as opposed to cascade-like neutral current interactions) are characterised by a very good angular resolution of < deg, which facilitates follow-up observations and potential source identification. The MAGIC telescopes performed follow-up observations of 4 HESE track-like events from the Northern hemisphere: HESE-37, HESE-38, HET (ATel #7856) and the GCN HESE alert from 27/04/2016 (GCN #19363). No signal was detected. Here we present the results of those observations and discuss the implications for the constraints on the density of the astrophysical neutrino sources.