Robust supermassive black hole spin mass-energy characteristics: a new method and results

• Published in: Monthly notices of the Royal Astronomical Society Vol. 517; no. 4; pp. 5144 - 5159
• Main Author: Daly, Ruth A
• Format: Journal Article
• Language: English
• Published: 09.11.2022
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stac2976

ABSTRACT The rotational properties of astrophysical black holes are fundamental quantities that characterize the black holes. A new method to empirically determine the spin mass-energy characteristics of astrophysical black holes is presented and applied here. Results are obtained for a sample of 100 supermassive black holes with collimated dual outflows and redshifts between about 0 and 2. An analysis indicates that about two-thirds of the black holes are maximally spinning, while one-third have a broad distribution of spin values; it is shown that the same distributions describe the quantity ${(M_{\rm rot}/M_{\rm irr})}$. The new method is applied to obtain the black hole spin mass-energy, ${M_{\rm {spin}}}$, available for extraction relative to: the maximum possible value, the irreducible black hole mass, and the total black hole mass, ${M_{\rm {dyn}}}$. The total energy removed from the black hole system and deposited into the circumgalactic medium via dual outflows over the entire outflow lifetime of the source, ${E_{\rm {T}}}$, is studied relative to ${M_{\rm {dyn}}}$ and relative to the spin energy available per black hole, ${E_{\rm spin}/(M_{\odot }c^2)}$. The mean value of ${{\rm Log}(E_{\rm T}/M_{\rm dyn})}$ is about (−2.47 ± 0.27). Several explanations of this and related results are discussed. For example, the energy input to the ambient gas from the outflow could turn-off the accretion, or the impact of the black hole mass-loss on the system could destabilize and terminate the outflow. The small values and restricted range of values of ${{\rm Log}(E_{\rm T}/M_{\rm dyn})}$ and ${{{\rm Log}}}(E_{\rm T}/E_{\rm spin})}$ could suggest that these are fundamental properties of the primary process responsible for producing the dual collimated outflows.