Gamma-Ray Emission in the Seyfert Galaxy NGC 4151: Investigating the Role of Jet and Coronal Activities

TL;DR

This study investigates the origin of gamma-ray emission in NGC 4151, exploring whether jet activity, coronal activity, or their combination explains the observed spectrum, and discusses the detectability of associated neutrinos.

Contribution

It proposes a method to distinguish between jet and coronal origins of gamma rays in NGC 4151 using energy-dependent variability analysis.

Findings

Jet activity alone can explain the gamma-ray spectrum.

Coronal activity contributes mainly below 1 GeV.

Detecting neutrinos from the corona is challenging with current observatories.

Abstract

NGC 4151, a nearby Seyfert galaxy, has recently been reported to emit gamma rays in the GeV range, posing an intriguing astrophysical mystery. The star formation rate of NGC 4151 is too low to explain the observed GeV flux, but the galaxy is known for its coronal activity in X-ray and jet activity in radio. We propose that either the combination of these two activities or the jet activity alone can account for the gamma-ray spectrum. An energy-dependent variability search will allow one to distinguish between the two scenarios, as the coronal component can only contribute at energies of $\lesssim1$ GeV. Our analysis also indicates that it might still be difficult to see coronal neutrinos from the apparently X-ray brightest Seyfert NGC 4151 with current-generation neutrino observatories.