A magnetar pulsar, also known simply as a magnetar, is a highly magnetized type of neutron star. Neutron stars are incredibly dense remnants left behind after the collapse of massive stars in supernova explosions. They typically have a mass greater than that of the Sun but are compressed into a small volume, roughly the size of a city.
What sets magnetars apart from other neutron stars is the strength of their magnetic fields. Magnetars possess the most intense magnetic fields observed in the universe, reaching magnitudes that are billions of times stronger than the magnetic fields of typical neutron stars. These magnetic fields are so powerful that they dramatically affect the behavior and properties of the magnetar.
The extreme magnetic fields of magnetars can give rise to a range of unique and intense phenomena, including:
Giant flares: Magnetars are known to occasionally release enormous bursts of energy in the form of intense gamma-ray flares. These flares are some of the most energetic events observed in the universe.
Soft gamma-ray repeaters (SGRs): Magnetars can exhibit regular, periodic bursts of gamma rays, known as SGR bursts. These bursts can repeat at irregular intervals and are thought to be caused by instabilities in the magnetar's magnetic field.
X-ray emissions: Magnetars emit copious amounts of X-rays due to their strong magnetic fields. X-ray telescopes have detected persistent X-ray emissions from magnetars, providing valuable insights into their properties.
Magnetar quakes: The intense magnetic fields of magnetars can cause the star's crust to become highly stressed. This can lead to powerful seismic disturbances, sometimes referred to as "magnetar quakes," which can generate ripples in the star's magnetic field.
Magnetars are fascinating objects that provide astrophysicists with valuable opportunities to study extreme physics under conditions that cannot be replicated in terrestrial laboratories. Although they represent a small fraction of the known neutron star population, the study of magnetars has significantly contributed to our understanding of the behavior of matter under extreme densities and magnetic fields.