A lepto-hadronic model of gamma rays from the Eta Carinae and prospects for neutrino telescopes

Abstract

The stellar binary $\eta$ Carinae has been observed during its full orbital period in gamma rays by the Fermi-Large Area Telescope (LAT). The shock-accelerated electrons in the colliding winds of the two stars radiate synchrotron photons in the magnetic field of the shocked region and inverse Compton photons, where the target photons are from the thermal emissions by the more massive and luminous of the two stars. The inverse Compton emission dominates the gamma-ray flux data from the $\eta$ Carinae, however the spectral energy distribution shows signature of a hadronic component in the $\sim 10$-300 GeV range during the periastron passage. Current and future air Cherenkov telescopes will be able to constrain this component at TeV energies. Acceleration of cosmic-ray protons to $\gg 1$ TeV energies in the colliding winds, required to explain the hadronic emission component through photopion interactions, can lead to detectable signal of $\gtrsim 10$ TeV neutrino events in large kilometer scale neutrino telescopes.

8 pages and 5 figures. Added gamma-gamma pair production calculation and expanded discussion. Main results unchanged. Accepted in Phys. Rev. D

References in corpus (5)

• Calculation of atmospheric neutrino flux using the interaction model calibrated with atmospheric muon data
• Detection of Gamma-ray Emission from the Eta-Carinae Region
• Hard X-ray emission from Eta Carinae
• The first full orbit of Eta Carinae seen by Fermi
• On the origin of γ-ray emission in η Carina

Cited by in corpus (6)

• Detection of very-high-energy γ-ray emission from the colliding wind binary η Car with H.E.S.S
• Hints of gamma-ray orbital variability from gamma^2 Velorum
• Eta Carinae with Fermi-LAT: Two full orbits and the third periastron
• Detection of very-high-energy gamma-ray emission from Eta Carinae during its 2020 periastron passage
• Searching for a Galactic component in the IceCube track-like neutrino events
• On the orbital variability of gamma-ray emission in ${\gamma }^2$ Velorum