Discovery of a 0.02 Hz QPO feature in the transient X-ray pulsar KS 1947+300

摘要: We report the discovery of quasi-periodic oscillations (QPOs) at 0.02 Hz in a transient highmass X-ray binary pulsar KS 1947+300 using RXTE Proportional Counter Array (PCA). The QPOs were detected during 2001 May–June, end long outburst. This is ninth accretion-powered high magnetic field which have been detected, and QPO frequency this source lowest class sources. unusual feature that though outburst lasted for more than 100 days, only last few days when intensity had decayed to 1.6 per cent peak intensity. rms value large, ∼15.4 ± 1.0 with slight positive correlation energy. detection strong pulsations low luminosity level suggests strength neutron star not as was predicted earlier on basis between spin-up torque luminosity.