The low or retrograde spin of the first extragalactic microquasar: implications for Blandford-Znajek powering of jets

Understand

Transitions to high mass accretion rates in black hole X-ray binaries are associated with the ejection of powerful, relativistically-moving jets.

• The mechanism powering such events is thought to be linked to tapping of the angular momentum (spin) of the black hole, the rate of accretion through the disc or some combination of the two.
• We can attempt to discriminate between these possibilities by comparing proxies for jet power with spin estimates.
• Due to the small number of sources reaching Eddington rates and have therefore been suggested to act as 'standard candles', there has been much recent debate as to whether a significant correlation exists between jet power and spin.