Abstract Details
| Name: Neal Thomas Affiliation: Christ (Deemed to be University), Bengaluru Conference ID: ASI2019_237 Title : Comprehensive spectral and temporal variability studies of Scorpius X-1 using RXTE data Authors and Co-Authors : Neal Titus Thomas, Shivappa B. Gudennavar, Bubbly S. G., Ranjeev Misra, Abstract Type : Poster Abstract Category : Stars, ISM and Galaxy Abstract : Neutron star low mass X-ray binaries (NS-LMXBs) are comprised of a weakly magnetized neutron star as the compact object and a donor star having mass ~ 1 - 2 M☉. They are traditionally divided into two main categories based on their correlated spectral and timing properties and the pattern they trace out in the colour-colour diagram: the so-called Z sources which are further classified as Cyg-like and Sco-like Z sources; and Atoll sources. The exact nature of the physical mechanisms that drive the Z and Atoll type of patterns are not known. Although increased mass accretion rate is thought to be one of the causes, it is yet to be established firmly. One such NS-LMXB is Scorpius X-1; which is the first identified X-ray extrasolar source and the brightest persistent X-ray source in the sky. It is a prototype of Sco-like Z sources and shows a distinct flaring along with strong and frequent increases in X-ray intensity. In addition to this, Scorpius X-1 exhibits a strong hard tail in its X-ray spectrum, which for a long time was considered to be a unique signature of black hole systems. The origin of this tail remains unclear and needs to be investigated further. The power density spectrum of Scorpius X-1 shows several aperiodic features like QPOs and noise. Several attempts have been made to explain their origin, however, consensus regarding it has not been reached. In order to study the long-term variability of the source, we have carried out comprehensive spectral and temporal variability studies on about six hundred observations spanning from January 1996 to December 2012 obtained from the publicly available archival data of Rossi X-ray Timing Explorer (RXTE) mission. These results will be presented. |