IOP Publishing Ltd.;Philadelphia: The American Astronomical Society
摘要:
摘要： ABSTRACT We report our measurements for the orbital and spin parameters of X 1822-371 using its X-ray partial eclipsing profile and pulsar timing from data collected by the Rossi X-ray Timing Explorer (RXTE). Four more X-ray eclipse times obtained by the RXTE 2011 observations were combined with historical records to trace the evolution of the orbital period. We found that a cubic ephemeris likely better describes the evolution of the X-ray eclipse times during a time span of about 34 years with a marginal second order derivative of s−1. Using the pulse arrival time delay technique, the orbital and spin parameters were obtained from RXTE observations from 1998 to 2011. The detected pulse periods show that the neutron star in X 1822-371 is continuously spun-up with a rate of s s−1. Although the evolution of the epoch of the mean longitude l = π/2 (i.e., Tπ/2) gives an orbital period derivative value consistent with that obtained from the quadratic ephemeris evaluated from the X-ray eclipse, the detected Tπ/2 values are significantly and systematically earlier than the corresponding expected X-ray eclipse times by 90 11 s. This deviation is probably caused by asymmetric X-ray emissions. We also attempted to constrain the mass and radius of the neutron star using the spin period change rate and concluded that the intrinsic luminosity of X 1822-371 is likely more than 1038 erg s−1. 其他題名： APJ 其他題名： Astrophys. J 出版者： Philadelphia: The American Astronomical Society 出版日期： 2016-11-01 出處： The Astrophysical journal, 2016-11, Vol.831 (1), p.29 資源來源： Institute of Physics Journals 版權： 2016. The American Astronomical Society. All rights reserved. 版權： Copyright IOP Publishing Nov 01, 2016 識別號： ISSN: 0004-637X 識別號： EISSN: 1538-4357 識別號： DOI: 10.3847/0004-637X/831/1/29
