On the possibilities of high-energy neutrino production in the jets of microquasar SS433 in light of new observational data

Abstract

Microquasar SS433 is composed by a supergiant star that feeds mass through a supercritical accretion disk to a ∼10 M⊙ black hole. The latter launches two oppositely directed jets that precess with a period of 162 days. The system has been detected at different spatial scales in frequencies ranging from radio to gamma rays, and has long been considered as a potential neutrino source which has been observed by AMANDA in the past, and later IceCube, leading to more restrictive upper bounds on the neutrino flux. In this work, we explore the possibilities that neutrinos could be produced in the jets of this source at levels consistent, or at least, not incompatible with any current data on electromagnetic emission available. In order to do so, we consider the injection of both electrons and protons at different positions in the jets, and we compute their broadband photon emission by synchrotron and interactions with ambient photons and matter. After correcting the high energy photon flux by the effect of γγ and γN absorption, we obtain the surviving flux that arrive on Earth and compare it with observational data by gamma-ray detectors. The flux of high energy neutrinos is consistently computed and we find that if they are eventually detected with IceCube, production must take place at the inner jets, where gamma-ray absorption is important, in order to avoid current VHE constraints form HESS and MAGIC. Additionally, we find that if the flux of 25 TeV gamma-rays recently detected with HAWC and which corresponds to the jet termination region were produced mainly by pp interactions, this would lead to a too faint neutrino flux that is beyond the reach of IceCube in its present configuration.