Newly formed magnetars as sources of gravitational waves

Two classes of high-energy sources, the soft gamma repeaters and the anomalous X-ray pulsars are believed to contain slowly spinning "magnetars", i.e. neutron stars the emission of which derives from the release of energy from their extremely strong magnetic fields (>= 1015 G). The enormous energy liberated in the 2004 December 27 giant flare from SGR 1806-20 (similar to 5 x 10(46) erg) points to an internal magnetic field strength of <= 1.0(16) G. Such strong fields are expected to be generated by a coherent alpha-Omega dynamo seconds after the Neutron Star (NS) formation, provided the spin period is in the millisecond range. Due to substantial deformation induced by these magnetic fields, newborn magnetars may radiate for a few days a strong gravitational wave signal (similar to 0.5-2 kHz range), which could be detected with Advanced LIGO-class detectors up to the Virgo cluster, where >= 1 y(-1) magnetars are expected to be born.