2007, S. Dall'Osso, L. Stella, Newborn magnetars as sources of gravitational radiation: constraints from high energy observations of magnetar candidates, Silvia Zane, Roberto Turolla, Dany Page (editors), Isolated Neutron Stars: From the Surface to the Interior, page 119,This signal could be detected with Advanced LIGO-class detectors up to the distance of the Virgo cluster, where ≥ 1 yr−1magnetars are expected to form.
2008, W. Becker, F, Haberl, J Trümper, 14: Pulsars and Isolated Neutron Stars, Joachim E. Trümper, Günther Hasinger (editors), The Universe in X-Rays, page 193,The radio-silent neutron stars include anomalous X-ray pulsars (AXPs), soft gamma-ray repeaters (SGRs), and “quiescent†neutron star candidates in SNRs. There is growing evidence that AXPs and SGRs are indeed magnetars (see 109 for a review).
2011, Yukikatsu Terada, Tadayasu Dotani, The International X-ray Observatiry and other X-ray missions, expectations for pulsar physics, Nanda Rea, Diego F. Torres (editors), High-Energy Emission from Pulsars and Their Systems: Proceedings of the First Session of the Sant Cugat Forum on Astrophysics, page 576,One of most mysterious features of magnetars is their X-ray luminosities, which always exceed the rotational energy loss. Thus, the energy source of the radiation of magnetars is a mysterious question.
