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arXiv · 1710.04820

A Suzaku View of Accretion Powered X-ray Pulsar GX 1+4

Yuki Yoshida·Shunji Kitamoto·Hiroo Suzuki·Akio Hoshino·Sachindra Naik·Gaurava K. Jaisawal
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Abstract

We present results obtained from a Suzaku observation of the accretion powered X-ray pulsar GX 1+4. Broad-band continuum spectrum of the pulsar was found to be better described by a simple model consisting of a blackbody component and an exponential cutoff power-law than the previously used compTT continuum model. Though the pulse profile had a sharp dip in soft X-rays ($<$10 keV), phase-resolved spectroscopy confirmed that the dimming was not due to increase in photoelectric absorption. Phase-sliced spectral analysis showed the presence of a significant spectral modulation beyond 10 keV except for the dip phase. A search for the presence of cyclotron resonance scattering feature in the Suzaku spectra yielded a negative result. Iron K-shell (K$_α$ and K$_β$) emission lines from nearly neutral iron ions ($<$Fe III) were clearly detected in the source spectrum. A significant K$_α$ emission line from almost neutral Ni atoms was detected for the first time in this source. We estimated the iron abundance of $\sim$80 % of the solar value and Ni/Fe abundance ratio of about two times of the solar value. We searched for a iron Ly$_α$ emission line and found a significant improvement in the spectral fitting by inclusion of this line.

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Yuki Yoshida, Shunji Kitamoto, Hiroo Suzuki, Akio Hoshino, Sachindra Naik, Gaurava K. Jaisawal. 2017-10-16. A Suzaku View of Accretion Powered X-ray Pulsar GX 1+4. https://doi.org/10.3847/1538-4357%2Faa6301

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