Particle acceleration in the X-ray knots of Centaurus A

Abstract

The radio galaxy Centaurus A (Cen A) is often considered the best candidate source of ultra-high-energy cosmic rays. X-ray and gamma-rays data provide evidence of particle acceleration to very-high energies in this source. Due the proximity and high power, and the detected emission of high-energy gamma-rays, Cen A is an unique target to explore particle acceleration with the Cherenkov Telescope Array (CTA), which will be built in the coming years. The measurements by the CTA will take our knowledge of particle acceleration in astrophysical sources to a new level. Understanding particle acceleration mechanisms is essential to compare to, and predict measurements for, CTA. This requires reliable models of particle acceleration in real sources. This project seeks to build models of particle acceleration in Cen A using a multi-wavelength approach. The substructures present in the jet, known as knots, are potential sites for particle acceleration and gamma-ray production. We will focus on a multi-messenger scenario for the particle acceleration in the X-ray knots. This work will be developed in the astrophysical group of the University of Oxford, an internationally recognized center of scientific excellence. The supervisor at Oxford is an establisged researcher, working actively on particle acceleration in radio galaxy jets, magnetohydrodynamical (MHD) simulations, and the origin of ultra-high-energy cosmic rays. The student is also well prepared for this internship project, being author of four papers published in recognized international journals, with another one in peer review process. We propose a challenging project, studying the acceleration in the knots of Cen A by MHD simulations and predicting the gamma-ray signal. Then, we will evaluate the possibility of measurement by the CTA. The junction of the available data of Cen A with future discoveries from CTA will certain help to understand the particle acceleration in this source.