Table of Contents
Physics Research International
Volume 2014, Article ID 375624, 8 pages
Research Article

Can SGRs/AXPs Originate from Neutron Star Binaries?

1Institute of Astronomy, National Tsing Hua University, Hsinchu 30013, Taiwan
2Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan

Received 11 June 2014; Revised 28 July 2014; Accepted 3 August 2014; Published 21 August 2014

Academic Editor: Israel Felner

Copyright © 2014 Joan Jing Wang and Hsiang-Kuang Chang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are two groups of enigmatic objects, which have been extensively investigated in past few decades. Based on the ample information about their timing behaviors, spectra, and variability properties, it was proposed that SGRs/AXPs are isolated neutron stars (NSs) with extremely strong magnetic fields, the so-called magnetars. Nonetheless, some alternative models are probably equally convincing such as those proposing that they are accreting NSs with a fall-back disk or rotation-powered magnetized and massive white dwarfs. The nature and nurture of SGRs/AXPs remain controversial. In this paper, we propose that SGRs/AXPs can, alternatively, originate from normal NSs in binary systems, which resorts to the reexplosion of normal NS induced by instant contraction of the massive star envelope in a Thorne-Żytkow object (TZO). The spin-period clustering is due to either the brake of a slowly rotating envelope or the frictional drag during the common-envelope phase.