Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic flux stabilizing thin accretion disks   We calculate the minimal amount of large-scale poloidal magnetic field that
has to thread the inner, radiation-over-gas pressure dominated region of a thin
disk for its thermal stability. Such a net field amplifies the magnetization of
the saturated turbulent state and makes it locally stable. For a $10 M_\odot$
black hole the minimal magnetic flux is $10^{24}(\dot M/\dot M_{\rm
Edd})^{20/21}\,\rm G\cdot cm^{2}$. This amount is compared with the amount of
uniform magnetic flux that can be provided by the companion star -- estimated
to be in the range $10^{22}-10^{24}\,\rm G\cdot cm^2$. If accretion rate is
large enough, the companion is not able to provide the required amount and such
a system, if still sub-Eddington, must be thermally unstable. The peculiar
variability of GRS 1915+105, an X-ray binary with the exceptionally high BH
mass and near-Eddington luminosity, may result from the shortage of large scale
poloidal field of uniform polarity.

22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol