Black hole systems, composed of a black hole, accretion disk, and collimated outflow, are studied here. Three active galactic nucleus (AGN) samples including 753 AGNs and 102 measurements of four ...stellar-mass galactic black holes (GBHs) are studied. Applying the theoretical considerations described by Daly, general expressions for the black hole spin function and accretion disk magnetic field strength are presented and applied to obtain the black hole spin function, spin, and accretion disk magnetic field strength in dimensionless and physical units for each source. Relatively high spin values are obtained; spin functions indicate typical spin values of about 0.6-1 for the sources. The distributions of accretion disk magnetic field strengths for the three AGN samples are quite broad and have mean values of about 104 G, while those for individual GBHs have mean values of about 108 G. Good agreement is found between spin values obtained here and published values obtained with well-established methods; comparisons for one GBH and six AGNs indicate that similar spin values are obtained with independent methods. Black hole spin and disk magnetic field strength demographics are obtained and indicate that black hole spin functions and spins are similar for all of the source types studied, including GBHs and different categories of AGNs. The method applied here does not depend on any specific accretion disk emission model and does not depend on a specific model that relates jet beam power to compact radio luminosity; hence, the results obtained here can be used to constrain and study these models.
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.
ABSTRACT
Mass accretion rates in dimensionless and physical units, and efficiency factors describing the total radiant luminosity of the disc and the beam power of the outflow are obtained and ...studied here for samples of black hole systems with outflows. Four samples of sources including 576 LINERs, 100 classical double (FRII) radio sources, 80 relatively local AGN, and 103 measurements of four stellar mass X-ray binary systems, referred to as Galactic Black Holes (GBHs), are included in the study. All of the sources have highly collimated outflows leading to compact radio emission or powerful extended (FRII) radio emission. The properties of each of the full samples are explored, as are those of the four individual GBH, and sub-types of the FRII and local AGN samples. Source types and sub-types that have high, medium, and low values of accretion rates and efficiency factors are identified and studied. A new efficiency factor that describes the relative impact of black hole spin and mass accretion rate on the beam power is defined and studied, and is found to provide a new and interesting diagnostic. Mass accretion rates for 13 sources and efficiency factors for 6 sources are compared with values obtained independently, and indicate that similar values are obtained with independent methods. The mass accretion rates and efficiency factors obtained here substantially increase the number of values available, and improve our understanding of their relationship to source types. The redshift dependence of quantities is presented and the impact on the results is discussed.
Relationships between beam power and accretion disc luminosity are studied for a sample of 55 high excitation radio galaxies (HERG), 13 low excitation radio galaxies (LERG), and 29 radio loud quasars ...(RLQ) with powerful outflows. The ratio of beam power to disc luminosity tends to be high for LERG, low for RLQ, and spans the full range of values for HERG. Writing general expressions for the disc luminosity and beam power and applying the empirically determined relationships allows a function that parametrizes the spins of the holes to be estimated. Interestingly, one of the solutions that is consistent with the data has a functional form that is remarkably similar to that expected in the generalized Blandford–Znajek model with a magnetic field that is similar in form to that expected in magnetically arrested disk (MAD) and advection-dominated accretion flow (ADAF) models. Values of the spin function, obtained independent of specific outflow models, suggest that spin and active galactic nucleus type are not related for these types of sources. The spin function can be used to solve for black hole spin in the context of particular outflow models, and one example is provided.
Studies of black hole spin and other parameters as a function of redshift provide information about the physical state and merger and accretion histories of the systems. One way that black hole spin ...may be estimated is through observations of extended radio sources. These sources, powered by outflows from an AGN, allow the beam power and total outflow energy to be studied. In a broad class of models, the beam power of the outflow is related to the spin of the black hole. This relationship is used to estimate black hole spins for 55 radio sources. The samples studied include 7 FR II quasars and 19 FR II radio galaxies with redshifts between 0.056 and 1.79, and 29 radio sources associated with CD galaxies with redshifts between 0.0035 and 0.291. The FR II sources studied have estimated spin values of between about 0.2 and 1; there is a range of values at a given redshift, and the values tend to increase with increasing redshift. Results obtained for FR II quasars are very similar to those obtained for FR II galaxies. A broader range of spin values are obtained for the sample of radio sources associated with CD galaxies studied. The fraction of the spin energy extracted per outflow event is estimated and ranges from about 0.03 to 0.5 for FR II sources and 0.002 to about 1 for radio sources associated with CD galaxies; the data are consistent with this fraction being independent of redshift though the uncertainties are large. The results obtained are consistent with those predicted by numerical simulations that track the merger and accretion history of AGN, supporting the idea that, for AGN with powerful large-scale outflows, beam power is directly related to black hole spin.
A Fundamental Line of Black Hole Activity Daly, Ruth A.; Stout, Douglas A.; Mysliwiec, Jeremy N.
The Astrophysical journal,
08/2018, Letnik:
863, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Black hole systems with outflows are characterized by intrinsic physical quantities such as the outflow beam power, Lj, the bolometric accretion disk luminosity, Lbol, and black hole mass or ...Eddington luminosity, LEdd. When these systems produce compact radio emission and X-ray emission, they can be placed on the fundamental plane (FP), an empirical relationship between compact radio luminosity, X-ray luminosity, and black hole mass. We consider a fundamental line (FL) of black hole activity written in terms of dimensionless intrinsic physical quantities: log(Lj/LEdd) = A log(Lbol/LEdd) + B or equivalently log(Lj/Lbol) = (A − 1) log(Lbol/LEdd) + B, and show that the FP may be written in the form of the FL. The FL has a smaller dispersion than the FP, suggesting the FP derives from the FL. Disk-dominated and jet-dominated systems have consistent best-fit FL parameters that suggest they are governed by the same physics. There are sharp cutoffs at Lbol/LEdd 1 and Lj/LEdd 0.2, and no indication of a strong break as . Consistent values of A are obtained for numerous samples, including FRII sources, LINERS, AGNs with compact radio emission, and Galactic black holes, which indicate a weighted mean value of A 0.45 0.01. The results suggest that a common physical mechanism related to the dimensionless bolometric luminosity of the disk controls the jet power relative to the disk power. The beam power Lj can be obtained by combining FP best-fit parameters and compact radio luminosity for sources that fall on the FP.
Beam power is a fundamental parameter that describes, in part, the state of a supermassive black hole system. Determining the beam powers of powerful classical double radio sources requires ...substantial observing time, so it would be useful to determine the relationship between beam power and radio power so that radio power could be used as a proxy for beam power. A sample of 31 powerful classical double radio sources with previously determined beam and radio powers is studied; the sources have redshifts between about 0.056 and 1.8. It is found that the relationship between beam power, L
j
, and radio power, P, is well described by log L
j
≈ 0.84(±0.14)log P+ 2.15(±0.07), where both L
j
and P are in units of 1044 erg s−1. This indicates that beam power is converted to radio power with an efficiency of about 0.7 per cent. The ratio of beam power to radio power is studied as a function of redshift; there is no significant evidence for redshift evolution of this ratio over the redshift range studied. The relationship is consistent with empirical results obtained by Cavagnolo et al. for radio sources in gas-rich environments, which are primarily Fanaroff-Riley type I sources, and with the theoretical predictions of Willott et al.
ABSTRACT
Six archival Chandra observations are matched with eight sets of radio data and studied in the context of the outflow method to measure and study the spin properties of $\rm {Sgr ~A^{*}}$. ...Three radio and X-ray data sets obtained simultaneously, or partially simultaneously, are identified as preferred for the purpose of measuring the spin properties of $\rm {Sgr ~A^{*}}$. Similar results are obtained with other data sets. Results obtained with the preferred data sets are combined and indicate weighted mean values of the spin function of $F = 0.62 \pm 0.10$ and dimensionless spin angular momentum of $a_* = 0.90 \pm 0.06$. The spin function translates into measurements of the black hole rotational mass, Mrot, irreducible mass, Mirr, and spin mass–energy available for extraction, Mspin, relative to the total black hole dynamical mass, Mdyn. Weighted mean values of (Mrot/Mdyn) = (0.53 ± 0.06), (Mirr/Mdyn) = (0.85 ± 0.04), (Mspin/Mdyn) = (0.15 ± 0.04), Mrot = (2.2 ± 0.3) × 106 M⊙, Mirr = (3.5 ± 0.2) × 106 M⊙, and Mspin = (6.2 ± 1.6) × 105 M⊙ are obtained; of course (Mrot/Mirr) = (0.62 ± 0.10) since (Mrot/Mirr) = F. Values obtained for $\rm {Sgr ~A^{*}}$ are compared with those obtained for M87 based on the published spin function, which indicate that M87 carries substantially more rotational energy and spin mass–energy relative to the total (i.e. dynamical) black hole mass, the irreducible black hole mass, and in absolute terms.
Bounds on Black Hole Spins Daly, Ruth A
The Astrophysical journal,
05/2009, Letnik:
696, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Beam powers and black hole masses of 48 extended radio sources are combined to obtain lower bounds on the spins and magnetic field strengths of supermassive black holes. This is done in the context ...of the models of Blandford & Znajek (the 'BZ' model) and Meier; a parameterization for bounds in the context of other models is suggested. The bounds obtained for very powerful classical double radio sources in the BZ model are consistent with black hole spins of order unity for sources at high redshift. The black hole spins are largest for the highest redshift sources and decrease for sources at lower redshift; the sources studied have redshifts between zero and two. Lower-power radio sources associated with central dominant galaxies may have black hole spins that are significantly less than one. Combining this analysis with other results suggests that the maximum values of black hole spin associated with powerful radio galaxies decline from values of order unity at a redshift of 2 to values of order 0.7 at a redshift of zero, falling roughly as , while lower power radio sources have spin values that range from about 0.1 to 0.8. These black hole spin values decrease if the data are considered in the context of the Meier model rather than the BZ model.
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