A Possible Magnetar Nature for IGR J16358-4726
Abstract
We present detailed spectral and timing analysis of the hard x-ray transient IGR J16358-4726 using multi-satellite archival observations. A study of the source flux time history over 6 years, suggests that lower luminosity transient outbursts can be occuring in intervals of at most 1 year. Joint spectral fits of the higher luminosity outburst using simultaneous Chandra/ACIS and INTEGRAL/ISGRI data reveal a spectrum well described by an absorbed power law model with a high energy cut-off plus an Fe line. We detected the 1.6 hour pulsations initially reported using Chandra/ACIS also in the INTEGRAL/ISGRI light curve and in subsequent XMM-Newton observations. Using the INTEGRAL data we identified a spin up of 94 s (dP/dt = 1.6E-4), which strongly points to a neutron star nature for IGR J16358-4726. Assuming that the spin up is due to disc accretion, we estimate that the source magnetic field ranges between 10^13 - 10^15 G, depending on its distance, possibly supporting a magnetar nature for IGR J16358-4726.
Keywords
Cite
@article{arxiv.astro-ph/0610768,
title = {A Possible Magnetar Nature for IGR J16358-4726},
author = {S. K. Patel and J. Zurita and M. Del Santo and M. Finger and C. Kouveliotou and D. Eichler and E. Gogus and P. Ubertini and R. Walter and P. Woods and C. A. Wilson and S. Wachter and A. Bazzano},
journal= {arXiv preprint arXiv:astro-ph/0610768},
year = {2008}
}
Comments
Accepted for publication in ApJ, 34 pgs, 14 figures, 4 tables