Nice article.

This one is part of the proof of the "always equatorial" position of an accretion disc & jet system of a black hole.

The "always equatorial" model is the one that explains the long term persistence in direction of the bipolar jets in giant elliptical and cD galaxies such as M87 and NGC 5128.

The measurement of spin also lends credence to the observation of drag & spin discs (also equatorial orientatiion) produced by supermassive slowly precessing black holes caused by the ferocious magnetic field produced by the combination of the hawking radiation effect, the temperature of the event horizon (planck temperature), and the very rapid spin of the black hole.

Article also gave a sideline effect which was an accurate measurement of the mass of the black hole in NGC 1365 (2 billion solar masses) which is relatively small as giant elliptical radio galaxies go,(by comparison M84 in the virgo cluster is 2.5 billion solar masses, and also hosts an equatorial drag & spin disc & bipolar jets).

Have a nice day: Ag