Investigation of quasi-periodic noise features in X-Persei

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: ZEYNEP ACUNER

Danışman: ALTAN BAYKAL

Özet:

In this thesis, timing and spectral properties of the Be type X-ray binary XPersei based on Rossi X-Ray Timing Explorer (RXTE) have been presented. Results of the power spectral analysis of RTXE data show QPO features detected between ⇠ 0.1-0.4 Hz which are reported for the first time. Another significant property of X-Per’s power spectra is the time dependent excess that can be observed between 0.01-0.08 Hz throughout the observations. These power excesses are interpreted as an inherent feature of source’s accretion. Besides this, hardness properties of the source have been carefully examined, which gives an insight to the QPO generation process. It has been concluded that QPO generation is most efficient during time intervals with soft photon abundance where highest QPO frequencies are observed (3-7/7-10 keV). Although X-Per’s general accretion pattern is that of wind accretion which matches with the predictions of Quasi-Spherical Acretion Theory, these investigations also imply the existence of an accretion disk that exists throughout the RXTE observations around the pulsar 4U 0352+309. Values estimated for inner Keplerian radius and magnetic field hence the magnetospheric radius clearly indicate that the accretion disk and the magnetic field closely interact which can be considered as the source of aperiodic variability.