Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Coronal outflow dominated accretion discs: a new possibility for low
  luminosity black holes?   The spectral energy distributions of galactic black holes in the low/hard
state and of low-luminosity AGN possess many common features, the most
prominent being: compact, flat (or inverted) spectrum radio cores with high
brightness temperatures; excess red and infrared emission, often correlated
with the radio flux; an extremely weak (or absent) quasi-thermal hump and a
hard X-ray power-law with high energy cut-off. These sources are thought to be
accreting at low rates and advection (or convection) dominated accretion flows
are usually considered the best candidates to explain them. Here we present an
alternative possibility, involving strong, unbound, magnetic coronae generated
by geometrically thin, optically thick accretion discs at low accretion rates.
First we show that, if angular momentum transport in the disc is due to
magnetic turbulent stresses, the magnetic energy density and effective viscous
stresses inside the disc are proportional to the geometric mean of the total
(gas plus radiation) and gas pressure. Therefore the corona is less powerful in
a radiation pressure dominated disc, and the relative fraction of the power
liberated in the corona increases as the accretion rate decreases. Furthermore,
we discuss reasons why energetically dominant coronae are ideal sites for
launching powerful jets/outflows, both MHD and thermally driven. In analysing
the spectral properties of such coronal outflow dominated accretion discs, we
reach the important conclusion that if the jet/outflow is, as is likely,
radiatively inefficient, then so is the source overall, even without advection
of energy into the black hole being relevant for the dynamics of the accretion
flow.

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The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom