X-RAY VARIABILITY AND 1MHZ OSCILLATIONS IN TT ARIETIS


Baykal A., Esendemir A., Kızıloğlu Ü., Alpar M. A. , Ögelman H., ERCAN N., ...Daha Fazla

ASTRONOMY & ASTROPHYSICS, cilt.299, ss.421-426, 1995 (SCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 299 Konu: 2
  • Basım Tarihi: 1995
  • Dergi Adı: ASTRONOMY & ASTROPHYSICS
  • Sayfa Sayıları: ss.421-426

Özet

Using the archival ROSAT observation of TT Ari, Xray energy spectra in different orbital phases and power spectra of the intensity time series are presented. Spectral fits show that the source gets brighter during the observation. The orbital modulation of the X-ray counting rate and bremsstrahlung temperature suggests that soft X-ray emission peaks in the orbital phase interval 0.75-0.90, when an outer disk hot spot is near the line of sight. This correlates with the orbital modulation of C IV(lambda 1549) absorption (Robinson and Cordova 1993). Timing analysis indicates that while the source gets brighter, the frequency of the 1mHz oscillation is not correlated with X-ray intensity. This implies that in the X-rays from TT Ari, the beat frequency model is not appropriate for explaining the changes in the 1mHz oscillations.