Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The population of black widow pulsars   We consider the population of black widow pulsars (BWPs). The large majority
of these are members of globular clusters. For minimum companion masses < 0.1
Msun, adiabatic evolution and consequent mass loss under gravitational
radiation appear to provide a coherent explanation of all observable
properties. We suggest that the group of BWPs with minimum companion masses >
0.1 Msun are systems relaxing to equilibrium after a relatively recent capture
event. We point out that all binary millisecond pulsars (MSPs) with orbital
periods P < 10 h are BWPs (our line of sight allows us to see the eclipses in
10 out of 16 cases). This implies that recycled MSPs emit either in a wide fan
beam or a pencil beam close to the spin plane. Simple evolutionary ideas favour
a fan beam.

23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas