A low-magnetic-field Soft Gamma Repeater
Abstract
Soft gamma repeaters and anomalous x-ray pulsars form a rapidly increasing group of x-ray sources exhibiting sporadic emission of short bursts. They are believed to be magnetars, i.e. neutron stars powered by extreme magnetic fields, B~10^{14}-10^{15} Gauss. We report on a soft gamma repeater with low magnetic field, SGR 0418+5729, recently detected after it emitted bursts similar to those of magnetars. X-ray observations show that its dipolar magnetic field cannot be greater than 7.5x10^{12} Gauss, well in the range of ordinary radio pulsars, implying that a high surface dipolar magnetic field is not necessarily required for magnetar-like activity. The magnetar population may thus include objects with a wider range of B-field strengths, ages and evolutionary stages than observed so far.
Cite
@article{arxiv.1010.2781,
title = {A low-magnetic-field Soft Gamma Repeater},
author = {N. Rea and P. Esposito and R. Turolla and G. L. Israel and S. Zane and L. Stella and S. Mereghetti and A. Tiengo and D. Gotz and E. Gogus and C. Kouveliotou},
journal= {arXiv preprint arXiv:1010.2781},
year = {2015}
}
Comments
Accepted by Science. First published on-line in ScienceXpress on 2010 October 14th: http://www.sciencexpress.org