Modelling high-energy gamma rays from theVela pulsar: curvature vs. synchro-curvature emission.

Project Description:

Pulsars emit pulsed emission across the entire electromagnetic spectrum and exhibit light curve features that are strongly dependent on energy. Continued detections by the space and ground-based Cherenkov instruments in the high to very-high energy band raise important questions about our understanding of the local environment (their magnetospheres), as well as the electrodynamics and particle physics within the environments of these extreme astrophysical sources. Recent kinetic simulations sparked a debate regarding the dominant emission mechanism responsible for pulsed GeV gamma-ray emission from pulsars. Some models invoke curvature or synchro-curvature (SC) emission, while others favor synchrotron radiation, with both mechanisms operating in the current sheet. We will explore the high-energy curved spectrum of the Vela pulsar in the 0.1 - 100 GeV band, as observed by Fermi Large Area Telescope (LAT) and H.E.S.S. II, by doing a comparison study between radiation mechanisms, i.e., curvature vs. SC. In the context of each radiation mechanism (curvature is a limiting case of the more general SC), we will start off by considering only a single particle, and investigate the evolution of the particle dynamics along the magnetic field lines. We will then predict energy-dependent light curves as well as phase-averaged spectra in a global force-free field structure, considering both curvature and SC emission, and study the differences in model outputs.

Research Area:

Astrophysics

Project Level:

Honours

This Project Is Offered At The Following Node(s):

(NWU)

Special Requirements:

The student is expected to do the project independently, i.e., a background study, generating results, report writing, present the project, and plan time wisely. The supervisor is available during the course of the project to assist with planning, having discussions for explaining material or answer questions related to the project, and preparing the student for the presentation. The student should have a B.Sc. degree in physics, mathematics, programming, or other related fields, as well as a basic knowledge of programming in any language (preferably Python / C / C++), or be willing to learn.