Speaker
Ms
Pragati Pradhan
(St. Joseph's College, Darjeeling, India & North Bengal University, Siliguri, India)
Description
We present a broadband spectral analysis of classical HMXBs (supergiant and
Be/X-ray binaries) and Supergiant Fast X-ray Transients (SFXTs) using data
from XIS and PIN instruments onboard Suzaku. After fitting the X-ray spectra
of 36 sources with a single model: a powerlaw and a high energy cutoff (where
required), we studied the correlation between various spectral parameters.
We present the following results: (i) We find a linear correlation between
the cyclotron line energy and the cutoff energy as is previously reported in
literature using RXTE and Ginga data (for cyclotron line energy less than
35 keV). Using Suzaku obervations, though, we find that there is more than
one slope of variation between the two quantities. (ii) The variation of cutoff
energy with luminosity indicate that NS-HMXBs seem to be divided into
two classes following two different trends. This division is not on the basis
of different beaming mechanism, as can be studied from the pattern of their
pulse profiles. These two groups, notably, show two different patterns when
the variation of their photonindex is studied against their cutoff energies. (iii)
As seen for LMXBs, we note an anticorrelation between the spectral index and
luminosity. (iv) Unlike previous works, we do not see anticorrelation between
the X-ray luminosity and the equivalent width of Kα lines (Baldwin effect).
(vi) The equivalent width and the iron Kα line flux is smaller in SFXTs than
in classical NS-HMXBs.
| Collaboration | Raman Research Institute, Bangalore, India & ISDC, University of Geneva, Switzerland |
|---|
Author
Ms
Pragati Pradhan
(St. Joseph's College, Darjeeling, India & North Bengal University, Siliguri, India)
Co-authors
Dr
Bikash Paul
(North Bengal University, Raja Rammohanpur, District Darjeeling-734013, West Bengal, India)
Dr
Biswajit Paul
(Raman Research Institute, Sadashivnagar, Bangalore-560080, India)
Dr
Enrico Bozzo
(ISDC, University of Geneva, Chemin d’Ecogia 16, Versoix, 1290, Switzerland)
