Orbital, precessional and flaring variability of Cygnus X-1

Details Orbital, precessional and flaring variability of Cygnus X-1 Orbital, precessional and flaring variability of Cygnus X-1

1999-06-23

arxiv.org/abs/astro-ph/9906365v1

Mon.Not.Roy.Astron.Soc. 309 (1999) 1063

Astronomy and Astrophysics

Astrophysics

Accepted for publication in MNRAS, 2 figures in colour

Scientific paper

10.1046/j.1365-8711.1999.02919.x

We present the results of a 2.5-year multiwavelength monitoring programme of Cygnus X-1, making use of hard and soft X-ray data, optical spectroscopy, UBVJHK photometry and radio data. In particular we confirm that the 5.6-day orbital period is apparent in all wavebands and note the existence of a wavelength-dependence to the modulation, in the sense that higher energies reach minimum first. We also find a strong modulation at a period of 142 +/- 7 days, which we suggest is due to precession and/or radiative warping of the accretion disc. Strong modulation of the hard and soft X-ray flux at this long period may not be compatible with simple models of an optically thin accretion flow and corona in the low state. We present the basic components required for more detailed future modelling of the system - including a partially optically thick jet, quasi-continuous in the low state, the base of which acts as the Comptonising corona. In addition, we find that there are a number of flares which appear to be correlated in at least two wavebands and generally in more. We choose two of these flares to study in further detail and find that the hard and soft X-rays are well-correlated in the first and that the soft X-rays and radio are correlated in the second. In general, the optical and infrared show similar behaviour to each other but are not correlated with the X-rays or radio.

Affiliated with

Also associated with

No associations

Rating

Orbital, precessional and flaring variability of Cygnus X-1 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Orbital, precessional and flaring variability of Cygnus X-1, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Orbital, precessional and flaring variability of Cygnus X-1 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-28728