SAX J1808.4-3658: high resolution spectroscopy and decrease of pulsed fraction at low energies
Abstract
XMM-Newton observed the accreting millisecond pulsar SAX J1808.4-3658 during its 2008 outburst. We present timing and spectral analyses of this observation, in particular the first pulse profile study below 2 keV, and the high-resolution spectral analysis of this source during the outburst. Combined spectral and pulse profile analyses suggest the presence of a strong unpulsed source below 2 keV that strongly reduces the pulsed fraction and a hard pulsed component that generates markedly double peaked profiles at higher energies. We also studied the high-resolution grating spectrum of SAX J1808.4-3658, and found several absorption edges and Oxygen absorption lines with whom we infer, in a model independent way, the interstellar column densities of several elements in the direction of SAX J1808.4-3658.
Keywords
Cite
@article{arxiv.0903.3210,
title = {SAX J1808.4-3658: high resolution spectroscopy and decrease of pulsed fraction at low energies},
author = {Alessandro Patruno and Nanda Rea and Diego Altamirano and Manuel Linares and R. Wijnands and M. van der Klis},
journal= {arXiv preprint arXiv:0903.3210},
year = {2009}
}
Comments
MNRAS Letters, accepted