Hadronic Gamma-Ray and Neutrino Emission from Cygnus X-3

Abstract

Cygnus X-3 (Cyg X-3) is a remarkable Galactic microquasar (X-ray binary) emitting from radio to $\gamma$-ray energies. In this paper, we consider hadronic model of emission of $\gamma$-rays above 100 MeV and their implications. We focus here on the joint $\gamma$-ray and neutrino production resulting from proton-proton interactions within the binary system. We find that the required proton injection kinetic power, necessary to explain the $\gamma$-ray flux observed by AGILE and Fermi-LAT, is $L_p\sim 10^{38}\mathrm{erg}{\mathrm{s}}^{-1}$, a value in agreement with the average bolometric luminosity of the hypersoft state (when Cygnus X-3 was repeatedly observed to produce transient $\gamma$-ray activity). If we assume an increase of the wind density at the superior conjunction, the asymmetric production of $\gamma$-rays along the orbit can reproduce the observed modulation. According to observational constraints and our modelling, a maximal flux of high-energy neutrinos would be produced for an initial proton distribution with a power-law index $\alpha =2.4$. The predicted neutrino flux is almost two orders of magnitude less than the 2-month IceCube sensitivity at $\sim$1 TeV. If the protons are accelerated up to PeV energies, the predicted neutrino flux for a prolonged "soft X-ray state" would be a factor of about 3 lower than the 1-year IceCube sensitivity at $\sim$10 TeV. This study shows that, for a prolonged soft state (as observed in 2006) possibly related with $\gamma$-ray activity and a hard distribution of injected protons, Cygnus X-3 might be close to being detectable by cubic-kilometer neutrino telescopes such as IceCube.

Accepted for publication in ApJ

References in corpus (6)

• Time-Integrated Searches for Point-like Sources of Neutrinos with the 40-String IceCube Detector
• Effects of the stellar wind on X-ray spectra of Cygnus X-3
• The AGILE monitoring of Cygnus X-3: transient gamma-ray emission and spectral constraints
• A classification of the X-ray and radio states of Cyg X-3 and their long-term correlations
• Searches for high-energy neutrino emission in the Galaxy with the combined IceCube-AMANDA detector
• Estimation of the neutrino flux and resulting constraints on hadronic emission models for Cyg X-3 using AGILE data

Cited by in corpus (16)

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• AGILE detection of a candidate gamma-ray precursor to the ICECUBE-160731 neutrino event
• PeV photon and neutrino flares from galactic gamma-ray binaries
• Search for High-Energy Neutrino Emission from Galactic X-ray Binaries with IceCube
• High-energy gamma-ray activity from V404 Cygni detected by AGILE during the 2015 June outburst
• The Origin of the Multiwavelength Emission of PKS 0502+049
• AGILE detection of gamma-ray sources coincident with cosmic neutrino events
• Time-dependent search for neutrino emission from x-ray binaries with the ANTARES telescope
• The gamma-ray source AGL J2241+4454 as the possible counterpart of MWC 656
• INTEGRAL discovery of a high-energy tail in the microquasar Cygnus X-3
• Microquasar Cyg X-3 -- a unique jet-wind neutrino factory?
• Broadband Emission Spectra from the Cygnus X-3 Jet in the Soft Spectral State
• Cygnus X-3 as semi-hidden PeVatron
• Galactic sources of high energy neutrinos: Expectation from gamma-ray data