Neutron stars are the collapsed cores of high-mass stars. Although they are more massive than the Sun their radii are about 10 km making them the most compact objects after black holes. Strongly magnetized, rapidly rotating neutron stars are observed as pulsars. The magnetosphere of a pulsar is filled with very dense electron-positron pairs that are accelerated in the polar caps. Pulsars exhibit significant fluctuations in their pulse profiles as well as substantial variations in flux. However, the physical mechanism underlying the variabilities of the pulsar emission has yet to be understood.


In collaboration with two renowned CNRS researchers from Grenoble, Dr. Benoit Cerutti and Dr. Guillaume Dubus, we have investigated the role played by magnetic reconnection and the subsequent formation of plasmoids (magnetic islands) in the pulsar wind as a possible source of intrinsic pulse-to-pulse variability in the high-energy emission pattern. In this work, entitled 'Intra-pulse variability induced by plasmoid formation in pulsar magnetospheres' (https://arxiv.org/abs/2205.01942) and published in May 2022 in Astronomy & Astrophysics (https://www.aanda.org/articles/aa/full_html/2022/05/aa43152-22/aa43152-22.html), we present results of some particle in cell (PIC) simulations of the plasma in the magnetosphere of a pulsar. The prediction of subpulses at specific pulse phases provides a new observational test of the magnetic reconnection scenario as the origin of the pulsed incoherent emission. This work is a part of the Ph.D. studies of Res. Assis. İ. Ceyhun ANDAÇ which is supervised by Prof. Dr. K. Yavuz EKŞİ from The Department of Physics Engineering.