Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Binary Black Holes at the Core of Galaxy Clusters   In this paper we push forward and exploit an analogy between the morphologies
of the X-ray cavities observed in some galaxy clusters, and the optically
deficient point-symmetric bubbles occurring in some planetary nebulae (PNe).
Point-symmetric PNe are thought to be shaped by stellar binary interactions;
namely, the presence of a companion to the PN's progenitor star is required. We
suggest that similar point-symmetric structures in the X-ray cavities of galaxy
clusters might be associated with the presence of massive binary black holes. A
systematic cataloguing of high-resolution images of the diffuse X-ray emission
at the core of galaxy clusters might contribute to individuate massive binary
black holes.

3
The categories of this paper are: physics
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th