Zusammenfassung
The uncertainty region of the highly energetic neutrino IceCube200107A
includes 3HSP J095507.9+355101 ($z$~=~0.557), an extreme blazar, which was
detected in a high, very hard, and variable X-ray state shortly after the
neutrino arrival. Following a detailed multi-wavelength investigation, we
confirm that the source is a genuine BL Lac, contrary to TXS 0506+056, the
first source so far associated with IceCube neutrinos, which is a
"masquerading" BL Lac. As in the case of TXS0506+056, 3HSP J095507.9+355101 is
also way off the so-called "blazar sequence". We consider 3HSP J095507.9+355101
a possible counterpart to the IceCube neutrino. Finally, we discuss some
theoretical implications in terms of neutrino production.
Nutzer