We present the discovery of 163.65 Hz X-ray pulsations from IGR J17062-6143 in the only observation obtained from the source with the Rossi X-ray Timing Explorer. This detection makes IGR J17062-6143 the lowest-frequency accreting millisecond X-ray pulsar presently known. The pulsations are detected in the 2 - 12 keV band with an overall significance of 4.3 sigma, and an observed pulsed amplitude of 5.54 +- 0.67 % (in this band). Both dynamic power spectral and coherent phase timing analysis indicate that the pulsation frequency is decreasing during the 1.2 ks observation in a manner consistent with orbital motion of the neutron star. Because the observation interval is short, we cannot precisely measure the orbital period; however, periods shorter than 17 minutes are excluded at 90 % confidence. For the range of acceptable circular orbits the inferred binary mass function substantially overlaps the observed range for the AMXP population as a whole.
@article{arxiv.1702.05449,
title = {IGR J17062-6143 is an Accreting Millisecond X-ray Pulsar},
author = {Tod E. Strohmayer and Laurens Keek},
journal= {arXiv preprint arXiv:1702.05449},
year = {2017}
}
Comments
9 pages, 5 figures, published in The Astrophysical Journal Letters