Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic Energy of the Intergalactic Medium from Galactic Black Holes   A quantitative analysis of two radio source samples having opposite extremes
of ambient gas density leads to important new conclusions about the magnetic
energy in the IGM. We conclude that giant sources in rarefied IGM environments,
which contain magnetic energies E_B ~ 10^60-61 ergs, can be viewed as important
"calorimeters" of the minimum energy a black hole (BH) accretion disk system
injects into the IGM. In contrast to the radiation energy released by BH
accretion, most of the magnetic energy is "trapped" initially in a volume, up
to ~10^73 cm^3, around the host galaxy. But since these large, Mpc scale radio
lobes are still overpressured after the AGN phase, their subsequent expansion
and diffusion will magnetize a large fraction of the entire IGM. This suggests
that the energy stored in intergalactic magnetic fields will have a major, as
yet underestimated effect on the evolution of subsequently forming galaxies.
Comparison with the second sample, consisting of sources within 150 kpc of rich
cluster cores, shows that the minimum magnetic energy E_B can be a strongly
variable fraction of the inferred accretion energy E_acc, and that it depends
on the ambient IGM environment. AGNs inject significant energy as PdV work on
the thermal ICM gas, and their magnetic energy, even ignoring the contribution
from stellar and starburst outflows, is sufficient to account for that recently
found beyond the inner cores of galaxy clusters. Other loss processes in the
course of the lobe expansion are considered. We conclude that the aggregate IGM
magnetic energy derived purely from galactic black holes since the first epoch
of significant galaxy BH formation is sufficiently large that it will have an
important influence on the process of both galaxy and visible structure
formation on scales up to ~ 1Mpc.

1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn