Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic field dispersion in the neighbourhood of Bok Globules   We performed an observational study of the relation between the interstellar
magnetic field alignment and star formation in twenty (20) sky regions
containing Bok Globules. The presence of young stellar objects in the globules
is verified by a search of infrared sources with spectral energy distribution
compatible with a pre main-sequence star. The interstellar magnetic field
direction is mapped using optical polarimetry. These maps are used to estimate
the dispersion of the interstellar magnetic field direction in each region from
a Gaussian fit, sigma_B. In addition to the Gaussian dispersion, we propose a
new parameter, eta, to measure the magnetic field alignment that does not rely
on any function fitting. Statistical tests show that the dispersion of the
magnetic field direction is different in star forming globules relative to
quiescent globules. Specifically, the less organised magnetic fields occur in
regions having young stellar objects.

10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
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The categories of this paper are: eess
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga