Abstract Details
| Name: Neal Titus Thomas Affiliation: Christ University Conference ID: ASI2018_1624 Title : Spectro-Timing analysis of neutron star low mass X-ray binaries Authors and Co-Authors : Shivappa B. Gudennavar Christ University Abstract Type : Poster Abstract Category : Stars,ISM and the Galaxy Abstract : Weakly magnetized neutron stars in low mass X-ray binaries (which have mass of the companion star ~1 - 2 M☉), show two patterns of X-ray timing and spectral behaviour. (Hasinger and van der Klis, 1989). 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 source and atoll sources which have ‘banana’ and ‘island’ states. However, analysis of certain atoll sources (Aql X-1, 4U 1608-522 and 4U 1705-44) for over a period of 5 years show that some atoll sources that vary by the widest range in X-ray intensity trace a Z pattern in the CD (Muno et al, 2002). Certain other sources like 4U 1820-303 and 4U 1728-34 trace only certain features of the Z track and others like GX-13+1 exhibits both Z and atoll properties. The neutron star transient XTE J1701-462 during, its outburst was seen to move through all the subclasses (Lin et al, 2008). In addition to these, neutron star low mass X-ray binaries also show secular shifts in their colour-colour diagrams (Fridriksson et al, 2015). The exact nature of these deviation of sources from the standard subclasses is not well understood and the physical processes that drive the spectral variability is not well known, although increased mass accretion rate is thought to be one of the causes, it is yet to be established. We intend to identify sources like the ones mentioned above, which do not strictly conform to the Z or atoll subclasses and investigate their spectral and timing properties to establish the physical processes that distinguish the Z and atoll sources and the parameters on which this classification is dependent. We plan to work with data from the publicly available data from the Rossi X-ray Timing Explorer’s (RXTE) RXTE’s Proportional Counter Array (PCA) and High Energy X-ray Timing Experiment (HEXTE) and with AstroSat’s Large Array X-ray Proportional Counter (LAXPC) and Soft X-ray Telescope (SXT). The tools that we would use for extracting spectra, applying background corrections and generating light curves are: HeaSOFT 6.22.1, Xspec and LAXPC. |