Study of two pulsars with the Indian X-ray Astronomy Experiment

Abstract

The X-ray pulsars Cep X-4 and 4U 1907+09 were observed with the Indian X-ray Astronomy Experiment (IXAE). Observations of Cep-X4 were made during the declining phase of its latest 30 days outburst in 1997, July-August. The X-ray pulse profiles obtained during IXAE observations show inter-pulse dominated double-peak pulse. The second X-ray pulsar 4U 1907+09 with a period of 440s was observed in August 1996 and again in June 1998. The X-ray profile shows a double-peak pulse shape. The P obtained from these two observations indicate that the pulsar is in monotonically spin-down phase, at the rate of 0.23 s yr-1.