Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modelling the jet power in elliptical galaxies: support for rapidly
  spinning black holes   Recently, Allen et al. measured a tight correlation between the Bondi
accretion rates and jet powers of the nuclei of nearby X-ray luminous
elliptical galaxies. We employ two models of jet powering to understand the
above correlation and derive constraints on the spin and accretion rate of the
central black holes. The first is the Blandford-Znajek model, in which the spin
energy of the hole is extracted as jet power; the second model is an hybrid
version of the Blandford-Payne and Blandford-Znajek processes, in which the
outflow is generated in the inner parts of the accretion disk. We assume
advection-dominated accretion flows (ADAF) and account for general relativistic
effects. Our modelling implies that for typical values of the disk viscosity
parameter alpha~0.01-1 the tight correlation implies the narrow range of spins
j~0.7-1 and accretion rates Mdot(R_ms)~(0.01-1) Mdot_Bondi. Our results provide
support for the "spin paradigm" scenario and suggest that the central black
holes in the cores of clusters of galaxies must be rapidly rotating in order to
drive radio jets powerful enough to quench the cooling flows.

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The categories of this paper are: funct-an
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess