Transcripts of 13058_Pulsar_Particle_Simulation_1080

[Music] Narrator: A pulsar is the crushed core of an exploded star. Theorists have been trying to understand the details of how pulsars work ever since they were discovered in 1967 -- especially how they emit precisely timed pulses at radio to gamma-ray energies. Now, new computer simulations are providing surprising insights. A pulsar contains some of the strongest magnetic fields known and can spin thousands of times a second. That means it's a powerful dynamo, generating an electric field so strong particles are ripped out of the surface and accelerated into space. New computer simulations clearly show these incredible movements for the first time. Most of these particles are electrons and their antimatter counterparts, positrons. In these simulations, their colors get lighter as they attain higher energies. Electrons tend to race outward from the magnetic poles. Positrons mostly flow out at lower latitudes along a relatively thin structure called the current sheet. Ultimately, these outflows lead to the formation of a powerful wind that extends far from the pulsar. Magnetic field lines and the particles moving with them, sweep back and extend outward as the pulsar spins. Their rotational speed rises with greater distance, but there's a wall created by the ultimate speed limit -- the speed of light. Astronomers call this the light cylinder. Matter can't travel at the speed of light, so something has to give before the particles get this far. Just before reaching the light cylinder, these simulations show that a population of medium-energy electrons scatter wildly -- sometimes even back toward the pulsar. Some speed up, others slow. Most eventually slip past the light cylinder and head out into space. The simulations also show that a small percentage of positrons likely hold the secret to a pulsar's gamma-ray emission. Some of these particles become boosted to tremendous energies at points within the current sheet where magnetic field lines meet. These simulations bring scientists one step closer to understanding the incredible physics of pulsars, something that has kept theorists busy for decades. [Music] [These visualizations use data from simulations by Brambilla et al., 2018] [Beeping] [Beeping]