• Low frequency quasi-periodic oscillations in the hard x-ray emission from cygnus x-1

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      https://www.ias.ac.in/article/fulltext/joaa/019/01-02/0055-0061

    • Keywords

       

      X-rays: stars; stars: individual Cygnus Xl

    • Abstract

       

      The observations of the black hole binary Cygnus X-l were made in the energy band of 20–100keV with a balloon-borne Xenon-filled multiwire proportional counter telescope on 5th April 1992. Timing analysis of the data revealed the presence of Quasi-Periodic Oscillations (QPO) in the hard X-ray emission from the source. The QPO feature in the power density spectrum is broad with a peak at a frequency of 0.06 Hz. This result is compared with similar reports of QPOs in Cyg X-l in soft and hard X-rays. Short time scale random intensity variations in the X-ray light curve are described with a shot noise model.

    • Author Affiliations

       

      B. Paul1 P. C. Agrawal1 A. R. Rao1

      1. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai - 400 005, India
    • Dates

       
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