We present here the results of a time series analysis of the X-ray transient GRO J1719--24 (Nova Oph 1993) observed with the Burst And Transient Source Experiment (BATSE) onboard the Compton Gamma-Ray Observatory (CGRO). Our analysis covers the entire 80 day outburst, between 25 September and 14 December, 1993. We have analyzed an average of 35 source-on time intervals per day, each 512 bins of 1.024 seconds long between 20 - 100 keV. In total, about 1.5 * 10(6) seconds of data were selected during the outburst of GRO J1719--24. The corresponding FFT Power Density Spectra (PDS) cover the frequency range between 0.002 - 0.5 Hz. During the rise of the source, the PDS show a significant broad peak, indicative of quasi-periodic oscillations (QPO) in the time series. The centroid frequency of the QPO increased from ~ 45 mHz to ~ 80 mHz during the first week of the outburst and then increased gradually, but more slowly, to about ~ 120 mHz. The QPO are present in the PDS during the whole outburst of GRO J1719--24.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1994