Letter to the Editor

Disk-jet connection in Cygnus X-3

¹ Tata Institute of Fundamental Research, Mumbai 400005, India
² ISRO Satellite Center, Bangalore 560017, India

Corresponding author: M. Choudhury, manojulu@tifr.res.in

Received: 19 November 2001
Accepted: 16 January 2002

Abstract

We present the results of a detailed correlation study between the soft X-ray, hard X-ray, and radio emission (obtained from , BATSE, and GBI observations, respectively) of the bright radio emitting Galactic X-ray binary Cygnus X-3. We detect a very strong positive correlation between the soft X-ray and radio emission during the low-hard and minor flaring periods of the source, and an anti-correlation between the soft and hard X-ray emissions. We present statistical arguments to suggest that the anti-correlation between the radio and hard X-ray emission, reported earlier, is primarily due to their correlation and anti-correlation, respectively, with the soft X-ray emission. We make a wide band X-ray spectral study using the pointed RXTE observations and detect a pivotal behaviour in the X-ray spectrum. We argue that this X-ray spectral pivoting is responsible for the anti-correlation between the soft and hard X-ray emissions. The strong correlation between the soft X-ray and radio emission suggests a close link between the accreting mechanism, plasma cloud surrounding the compact object and the radio emission.