Rossi X-ray Timing Explorer discovery of coherent millisecond pulsations during an X-ray burst from KS 1731-260

被引:101
作者
Smith, DA [1 ]
Morgan, EH [1 ]
Bradt, H [1 ]
机构
[1] MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA
基金
美国国家航空航天局;
关键词
X-rays; bursts; stars;
D O I
10.1086/310604
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
A highly coherent 523.92 +/- 0.05 Hz periodic X-ray signal has been observed during a type I X-ray burst from the low-mass X-ray binary system KS 1731-260 with the Proportional Counter Array on Rossi X-Ray Timing Explorer. The spectral evolution of the burst indicates photospheric-radius expansion and contraction. The 524 Hz signal occurred at the end of the contraction phase, lasted for similar to 2 s, was highly coherent (Q greater than or similar to 900), and had a pulse fraction (ratio of sinusoidal amplitude to mean count rate) of 6.2% +/- 0.6%. KS 1731-260 is one of only three systems that have exhibited high-coherence millisecond oscillations during X-ray bursts and the first reported in which the pulsations are associated with photospheric contraction. These coherent signals may be interpreted as a direct indication of the neutron star spin.
引用
收藏
页码:L137 / L140
页数:4
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