Quarks and Compact Stars (QCS)
Oct. 20-22, 2014, KIAA at Peking University, Beijing - P. R. China

Wind braking of magnetars

Hao Tong

Xinjiang Astronomical Observatory, Chinese Academy of Sciences

Abstract: Magnetars are neutron stars powered by their super strong magnetic field. Observationally, anomalous X-ray pulsars and soft gamma-ray repeaters are believed to be magnetar candidates. While more and more multiwave observations of magnetars are available, unfortunately, we see accumulating failed predictions of the traditional magnetar model. These challenges urge rethinking of the traditional magnetar model. Wind braking of magnetars is one of the alternative modelings. The release of magnetic energy may generate a particle outflow (i.e., particle wind), that results in both an anomalous X-ray luminosity and significantly high spindown rate. In this wind braking scenario, only strong multipole field is necessary for a magnetar (a strong dipole field is no longer needed). Wind braking of magnetars may help us to understand their multiwave radiation properties, including (1) Non-detection of magnetars in Fermi-LAT observations, (2) The timing behaviors of low magnetic field magnetars, (3) The nature of anti-glitches, (4) The criterion for magnetar's radio emission, etc. In the wind braking model, timing events of magnetars (except for glitches which should be treated seperately) should always be accompanied by radiative events. The energy source for the particle wind can be from the magnetic energy or other reasonable energy reservoirs. (Based on Tong et al. 2013, ApJ, 768, 144 and subsequent works)