Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Magnetic Ribbon Model for Star-Forming Filaments   We develop a magnetic ribbon model for molecular cloud filaments. These
result from turbulent compression in a molecular cloud in which the background
magnetic field sets a preferred direction. We argue that this is a natural
model for filaments and is based on the interplay between turbulence, strong
magnetic fields, and gravitationally-driven ambipolar diffusion, rather than
pure gravity and thermal pressure. An analytic model for the formation of
magnetic ribbons that is based on numerical simulations is used to derive a
lateral width of a magnetic ribbon. This differs from the thickness along the
magnetic field direction, which is essentially the Jeans scale. We use our
model to calculate a synthetic observed relation between apparent width in
projection versus observed column density. The relationship is relatively flat,
similar to observations, and unlike the simple expectation based on a Jeans
length argument.

21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas