Magnetars: wind brakingH. Tong Xinjiang Astronomical ObservatoryPAC2012, XiangshanWhere are they?Traditional magnetar model Magnetar = young NS (SNR Manchester 1985; Xu Contopoulos Wang+ 2012) timing noise (Lyne+ 2010; Liu+ 2011) +a rotation-powered PWN Exist: intermittent pulsars (Kramer+ 2006; Camilo+ 2012)Intermittent pulsars B1931+24 (Kramer+ 2006)Magnetic dipole braking is only a pedagogical model! Rotating dipole in vaccum! Only as first order approximation to the real case Normal pulsars braked down by a rotation-powered particle windExistence of a particle wind in magnetars Varying period derivative Higher level of timing noise (compared with HBPSRs) Magnetism-powered PWN Correlation between Lpwn and Lx Higher Lpwn/EdotPSR J1622-4950 (Levin+ 2012)Rotational energy loss rate In summary Magnetism-powered particle wind When Lp Edot, a much lower magnetic field (plus higher order effects, magnetar case)Dipole magnetic field (1): magnetic dipole brakingPolar magnetic fieldDipole magnetic field (2): wind brakingDipole magnetic field in the case of wind brakingDipole B (case I)Conclusions (1) Wind braking: Wind-aided spin down A lower surface dipole field Magnetars=NS+strong multipole field Explain challenging observations of magnetars Their SNe energies are of normal value Non-detection of magnetars by Fermi-LAT The problem of low-B SGRs The relation between magnetars and HBPSRs A decreasing Pdot during magnetar outburst Low luminosity mangetars more likely to have radio emissons Two predictions A magentism-powered PWN A braking index n higher B (Tong & Xu 2012)A paradigm shift in the future? FAST: more radio-loud magnetars, HBPSRs, intermittent pulsars “Pulsars are electromagnetic braking”Pulsars are wind brakingFor short