EFFECTIVE INNER RADIUS OF TILTED BLACK HOLE ACCRETION DISKS
- Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424 (United States)
One of the primary means of determining the spin a of an astrophysical black hole is by actually measuring the inner radius r {sub in} of a surrounding accretion disk and using that to infer a. By comparing a number of different estimates of r {sub in} from simulations of tilted accretion disks with differing black hole spins, we show that such a procedure can give quite wrong answers. Over the range 0 <= a/M <= 0.9, we find that, for moderately thick disks (H/r approx 0.2) with modest tilt (15 deg.), r {sub in} is nearly independent of spin. This result is likely dependent on tilt, such that for larger tilts, it may even be that r {sub in} would increase with increasing spin. In the opposite limit, we confirm through numerical simulations of untilted disks that, in the limit of zero tilt, r {sub in} recovers approximately the expected dependence on a.
- OSTI ID:
- 21385094
- Journal Information:
- Astrophysical Journal (Online), Vol. 706, Issue 2; Other Information: DOI: 10.1088/0004-637X/706/2/L246; ISSN 1538-4357
- Country of Publication:
- United States
- Language:
- English
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