Orbital modulation and longer term variability in the radio emission from Cygnus X-1

被引：63

作者：

Pooley, GG

Fender, RP

Brocksopp, C

机构：

[1] Univ Cambridge, Cavendish Lab, Mullard Radio Astron Observ, Cambridge CB3 0HE, England

[2] Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands

[3] Univ Amsterdam, Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands

[4] Univ Sussex, Ctr Astron, CPES, Brighton BN1 9QJ, E Sussex, England

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 1999年 / 302卷 / 01期

关键词：

stars : individual : Cyg X-1; radio continuum : stars; X-rays : stars;

D O I：

10.1046/j.1365-8711.1999.02225.x

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

20 months of observations of the radio emission at 15 GHz from Cygnus X-l, starting in 1996 October, show variations at the binary period of 5.6 d, but with a phase offset from those at Xray wavelengths. There are also longer term variations on a time-scale of 150 d, which are only loosely related to the soft X-ray flux. The source was in the hard/low X-ray state throughout this period. The mean 15-GHz flux density is 13 mJy, the radio spectrum is flat and the semiamplitude of the orbital modulation is about 2 mJy. We discuss the possible origins of the modulation and the relationship to the soft X-ray emission.

引用

页码：L1 / L5

页数：5