ASCA Discovery of an X-ray Pulsar in the Error Box of SGR1900+14
  We present a 2 - 10 keV ASCA observation of the field around the soft gamma repeater SGR1900+14. One quiescent X-ray source was detected in this observation, and it was in the SGR error box. In 2 - 10 keV X-rays, its spectrum may be fit by a power law with index -2.2, and its unabsorbed flux is 9.6 x 10^-12 erg cm^-2 s^-1. We also find a clear 5.16 s period. The properties of the three well-studied soft gamma repeaters are remarkably similar to one another, and provide evidence that all of them are associated with young, strongly magnetized neutron stars in supernova remnants. 
K. Hurley, P. Li, C. Kouveliotou, T. Murakami, M. Ando, T. Strohmayer,   J. van Paradijs, F. Vrba, C. Luginbuhl, A. Yoshida,...