Very High Energy Cosmic Rays from Centaurus A

TL;DR

This paper investigates the origin of very high energy gamma-ray emission from Centaurus A, proposing that proton-proton interactions produce the observed GeV-TeV signals and supporting the detection of cosmic rays from this galaxy.

Contribution

It demonstrates that pp interactions explain Centaurus A's gamma-ray emission and supports the possibility of cosmic ray detection from this source.

Findings

pp interactions account for the observed gamma-ray emission

Many cosmic ray protons from Centaurus A can reach Earth

Supports recent cosmic ray observations by Pierre Auger Observatory

Abstract

Centaurus A is the nearest radio-loud AGN and is detected from radio to very high energy gamma-rays. Its nuclear spectral energy distribution shows two peaks, one in the far-infrared band and another at about 150 keV. By assuming the second peak is due to the electron synchrotron emission and the power index for the differential spectrum of the very high energy cosmic ray proton to be 2.7 we show that only pp interaction is responsible for the observed GeV-TeV emission from Centaurus A. We also found that indeed many very high energy cosmic ray protons from Centaurus A can arrive on Earth thus supporting the recent observation of two events by Pierre Auger Observatory.