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

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 ($<$10 keV), phase-resolved spectroscopy confirmed that the dimming was not due to increase in photoelectric absorption. Phase-sliced spectral analysis showed the presence of a significant spectral modulation beyond 10 keV except for the dip phase. A search for the presence of cyclotron resonance scattering feature in the Suzaku spectra yielded a negative result. Iron K-shell (K${}_{\alpha }$ and K${}_{\beta }$) emission lines from nearly neutral iron ions ($<$Fe III) were clearly detected in the source spectrum. A significant K${}_{\alpha }$ emission line from almost neutral Ni atoms was detected for the first time in this source. We estimated the iron abundance of $\sim$80 % of the solar value and Ni/Fe abundance ratio of about two times of the solar value. We searched for a iron Ly${}_{\alpha }$ emission line and found a significant improvement in the spectral fitting by inclusion of this line.

19 pages, 12 figures, 4 tables

References in corpus (4)

• Hard X-ray emission from the Galactic ridge
• The hard X-ray emission of X Per
• A Comparison of the Variability of the Symbiotic X-ray Binaries GX 1+4, 4U 1954+31, and 4U 1700+24 from Swift/BAT and RXTE/ASM Observations
• INTEGRAL observation of the accreting pulsar GX 1+4

Cited by in corpus (4)

• Understanding the spectral and timing behavior of a newly discovered transient X-ray pulsar Swift J0243.6+6124
• Comprehensive broadband study of accreting neutron stars with Suzaku: Is there a bi-modality in the X-ray spectrum?
• The Intensity Modulation of Fluorescent Line by a Finite Light Speed Effect in Accretion-Powered X-ray Pulsars
• Studies of Cepheus X-4 during 2018 outburst observed with AstroSat