K. Koyama, M. Kawada, H. Kunieda, Y. Tawara, Y. Takeuchi, and S. Yamauchi

Abstract

The discovery by the Ginga satellite of four X-ray pulsars and three hard X-ray sources in the Galactic plane at Galactic latitude roughly 30 deg and a distance of about 10 kpc (the '5-kpc arm') is reported. This finding indicates that the 5-kpc arm has been the site of vigorous formation of X-ray pulsars, and that in general their distribution might be expected to be nonuniform.