Magnetarer

Magnetarer, known in English as magnetars, are a class of isolated neutron stars characterized by extremely strong magnetic fields. They are believed to form from the remnants of massive stars after certain core-collapse supernovae, when the newborn neutron star develops a magnetic field on the order of 10^14–10^15 gauss and settles into a slow rotation with periods of a few seconds.

The strongest feature of magnetarer is their magnetic field, which decays over time and powers most of their high-energy emission. They exhibit persistent X-ray luminosities around 10^33–10^35 erg/s, often exceeding the rate at which the star loses rotational energy. In addition to steady emission, magnetarer produce bursts of X-rays and soft gamma rays, ranging from milliseconds to seconds, and can occasionally emit giant flares with energies up to 10^44–10^46 erg. Some objects are observed as soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs), which are now understood as manifestations of the same underlying population.

Spin periods of magnetarer are typically in the 2–12 second range, and their spin-down rates imply surface magnetic fields around 10^14–10^15 gauss. Most are found in the Milky Way and nearby galaxies, and many are associated with supernova remnants, indicating relatively young ages (tens of thousands of years).

Observations of magnetarer inform studies of ultra-strong magnetic fields, quantum electrodynamics in strong fields, and the physics of neutron-star magnetospheres. They remain an active area of high-energy astrophysics, with ongoing discoveries of new sources and burst activity.