Abstract Details
| Name: NAFISA AFTAB Affiliation: RAMAN RESEARCH INSTITUTE Conference ID: ASI2016_682 Title : Variability study of the High Mass X-ray binary IGR J18027–2016 with Swift–XRT Authors and Co-Authors : NAZMA ISLAM [ RAMAN RESEARCH INSTITUTE, INDIAN INSTITUTE OF SCIENCE] BISWAJIT PAUL [RAMAN RESEARCH INSTITUTE] Abstract Type : Poster Abstract Category : Stars, The Milky Way Galaxy and its neighbours Abstract : We report the results from pulsations and spectral analysis of a large number of observations of the HMXB pulsar IGR J18027–2016 with Swift–XRT, carried out at different orbital phases. We found a significant intensity variations in the system at different orbital phases, higher than the orbital intensity modulation. In some orbital phases, as seen in different XRT observations, the X-ray intensity is found to vary by a large factor, of about ∼50. In all the observations with sufficient number of source X-ray photons, pulsations have been detected around the reviously known pulse period of ∼140 sec, consistent with the source being a persistent pulsator. The pulse profiles, however, show a significant change from a double peaked pulse profiles in most cases to a singled peaked pulse profiles in some observations. The nature of the pulse profiles are found to be independent of the X-ray intensity. In some of the observations, a 6.4 keV Fe Kα emission line is detected with a high equivalent width (∼1 keV). The absorption column density is found to be large before and after the eclipse, consistent with most of it being due to the stellar wind of the companion star. Such X-ray intensity variations outside the X-ray eclipse and associated spectral properties indicates a variable accretion onto the neutron star, which could be caused by a clumpy nature of the stellar wind of the companion star. |