Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Disappearance of the Broad-Line Region in Low-Luminosity Agns   The disk-wind scenario for the broad-line region (BLR) and toroidal
obscuration in active galactic nuclei predicts the disappearance of the BLR at
low luminosities. In accordance with the model predictions, data from a nearly
complete sample of nearby AGNs show that the BLR disappears at luminosities
lower than $5\times\E{39} (M/10^7\Mo)^{2/3}$ erg s$^{-1)$, where $M$ is the
black hole mass. The radiative efficiency of accretion onto the black hole is
$\la \E{-3}$ for these sources, indicating that their accretion is
advection-dominated.

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The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con