Suzaku Observation of the Anomalous X-ray Pulsar CXOU J164710.2--455216

TL;DR

This paper reports Suzaku observations of the anomalous X-ray pulsar CXOU J164710.2-455216, revealing its pulse period, spectral components, and phase-resolved flux variations, contributing detailed timing and spectral analysis of this source.

Contribution

The study provides the first detailed timing and spectral analysis of CXOU J164710.2-455216 using Suzaku, including pulse profile, phase-resolved spectroscopy, and blackbody component characterization.

Findings

Detected pulse period of 10.61063 s with 3-peaked profile.

Spectra fitted with two blackbody components at 0.61 keV and 1.22 keV.

Observed flux of 2.6 x 10^{-11} erg/cm^2/s in 1-10 keV band.

Abstract

Suzaku TOO observation of the anomalous X-ray pulsar CXOU J164710.2-455216 was performed on 2006 September 23--24 for a net exposure of 38.8 ks. During the observation, the XIS was operated in 1/8 window option to achieve a time resolution of 1 s. Pulsations are clearly detected in the XIS light curves with a barycenter corrected pulse period of 10.61063(2) s. The XIS pulse profile shows 3 peaks of different amplitudes with RMS fractional amplitude of ~11% in 0.2--6.0 keV energy band. Though the source was observed with the HXD of Suzaku, the data is highly contaminated by the nearby bright X-ray source GX 340+0 which was in the HXD field of view. The 1-10 keV XIS spectra are well fitted by two blackbody components. The temperatures of two blackbody components are found to be 0.61+/-0.01 keV and 1.22+/-0.06 keV and the value of the absorption column density is 1.73+/-0.03 x 10^{22} atoms cm^{-2}. The observed source flux in 1-10 keV energy range is calculated to be 2.6 x 10^{-11} ergs cm^{-2} s^{-1} with significant contribution from the soft blackbody component (kT = 0.61 keV). Pulse phase resolved spectroscopy of XIS data shows that the flux of the soft blackbody component consists of three narrow peaks, whereas the flux of the other component shows a single peak over the pulse period of the AXP. The blackbody radii changes between 2.2-2.7 km and 0.28-0.38 km (assuming the source distance to be 5 kpc) over pulse phases for the soft and hard components, respectively. The details of the results obtained from the timing and spectral analysis is presented.