http://arxiv.org/abs/1509.01041
We present timing and spectral analysis of \emph{Swift}$-$XRT and \emph{RXTE}$-$PCA observations of the X-ray pulsar SWIFT J0513.4–6547 during its outburst in 2009 and its rebrightening in 2014. From 2009 observations, short term spin-up rate of the source was found to have about half of the value measured by Coe et al. From 2014 observations, short term spin-down rate of the source was measured to be about two orders of smaller than the average spin-down rate between 2009 and 2014. Pulse profiles of the source were found to contain double peaks, called primary and secondary. It was found that hardness ratios of the source correlate with the X-ray luminosity up to where 3-10 keV X-ray luminosity is $8.4\times 10^{36}$ erg s$^{-1}$. For higher luminosities, hardness ratios were found to be consistent with being constant. Pulsed fractions were found to be correlated with the source flux. Overall \emph{Swift}$-$XRT and \emph{RXTE}$-$PCA energy spectrum of the source fit equally well to a model consisting of blackbody and power law, and a model consisting of a power law with high energy cut-off. From the pulse phase resolved spectra and pulse phased resolved hardness ratios obtained using \emph{RXTE}$-$PCA, it was shown that spectrum is softer between primary and secondary peaks.
S. Sahiner, M. Serim, A. Baykal, et. al.
Fri, 4 Sep 15
20/58
Comments: 17 pages, 10 figures; submitted to MNRAS