Neutrinos from the Galactic Center Hosting a Hypernova Remnant

Hao-Ning He,Alexander Kusenko,Shigehiro Nagataki,Shiu-Hang Lee

doi:10.3847/1538-4357/ab7749

Abstract

Abstract Similar to star-forming galaxies or starburst galaxies, star-forming regions in our Galaxy can host cosmic-ray (CR) accelerators and rich gas as targets of hadronuclear interaction. By our estimations, the IceCube neutrino observatory might detect muon neutrinos from a CR accelerator associated with a molecular cloud complex in our Galaxy. The associated high-energy gamma-ray emission might be observed by the Cherenkov Telescope Array (CTA), High-Altitude Water Cherenkov Gamma-Ray Observatory (HAWC), and Large High Altitude Air Shower Observatory (LHAASO). Furthermore, taking the Galactic Center (GC) region as an example, we assume that a hypernova exploded in the past in the GC. We simulate the acceleration of CRs in the hypernova remnant (HNR) as well as their confinement and escape. The high-energy protons escape from the HNR, diffuse around the GC, interact with molecular clouds, and then produce gamma-rays and neutrinos. In the optimal cases, the GC would be a promising 100 TeV gamma-ray source for LHAASO’s one-month observation. We propose that neutrino-induced searching for starting track-like and high-energy starting events (HESEs) observed by IceCube, from the GC region with a radius of 1.°8, would help us discover the particle accelerator in the GC or constrain our models. Under the constraint from high-energy gamma-ray observations by the H.E.S.S. telescope, we estimate the exposure time needed to make a significant discovery for the optimal cases. The analysis combining observations of IceCube and ANTARES, starting track-like events and HESEs, future observations by neutrino detectors IceCube-Gen2 and KM3net, and gamma-ray telescopes CTA, HAWC, and LHAASO would help to constrain our models.

Highlights

The origin of high-energy neutrinos observed by the IceCube neutrino observatory is still unresolved
Similar to the SFGs/starburst galaxies (SBGs), star-forming regions in the Galaxy might be the host of CR accelerators and contain rich gas as the target of inelastic pp collision
10 TeV gamma-rays, we constrain the diffusion radius of neutrinos might be resolvable, as they are much closer to Earth than distant SFGs/SBGs

Summary

Introduction

The origin of high-energy neutrinos observed by the IceCube neutrino observatory is still unresolved. High-energy astrophysical neutrinos can be produced by the accelerated cosmic rays interacting with matter via hadronuclear interactions and with radiation via photohadronic interactions. Contribution of past galactic HNe to the observed high-energy neutrino flux. Under constraints from current gamma-ray observations on the GC region by the High-Energy Stereoscopic System Diffusion time of T = 10 T4 yr, the diffusion radius of protons with energy òp are approximated to be p ⎞0.3. In the star-forming region, the accelerator is plausibly associated with the MC complex, and the accelerated protons will interact with matters in the MC complex via inelastic pp collision, leading to the production of neutrinos and gammarays.

Neutrinos from a Past CR Accelerator Associated with an MC Complex

The Estimation

Simulations

The Detectability and Prospect

Findings

Conclusions and Discussions