No evidence for black hole spin powering of jets in X-ray binaries

• Published in: Monthly notices of the Royal Astronomical Society 2010-08, Vol.406 (3), p.1425-1434
• Main Authors: Fender, R. P., Gallo, E., Russell, D.
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics; Black holes; Double stars; Earth, ocean, space; Exact sciences and technology; ISM: jets and outflows; X-ray astronomy
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2010.16754.x

In this paper, we consider the reported measurements of black hole spin for black hole X-ray binaries and compare them against the measurements of jet power and speed across all accretion states in these systems. We find no evidence for any correlation between the properties of the jets and the reported spin measurements. These constraints are strongest in the hard X-ray state, which is associated with a continuous powerful jet. We are led to conclude that one or more of the following is correct: (i) the calculated jet power and speed measurements are wrong, (ii) the reported spin measurements are wrong and (iii) there is no strong dependence of the jet properties on the black hole spin. In addition to this lack of observational evidence for a relation between the black hole spin and jet properties in stellar mass black holes, we highlight the fact that there appear to be at least three different ways in which the jet power and/or radiative efficiency from a black hole X-ray binary may vary, two of which are certainly independent of spin because they occur in the same source on relatively short time-scales and the third which does not correlate with any reported measurements of black hole spin. We briefly discuss how these findings may impact upon interpretations of populations of active galactic nuclei in the context of black hole spin and merger history.