Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First evidence of external disc photoevaporation in a low mass star
  forming region: the case of IM Lup   We model the radiatively driven flow from IM Lup -- a large protoplanetary
disc expected to be irradiated by only a weak external radiation field (at
least 10$^4$ times lower than the UV field irradiating the Orion Nebula Cluster
proplyds). We find that material at large radii ($>400$AU) in this disc is
sufficiently weakly gravitationally bound that significant mass loss can be
induced. Given the estimated values of the disc mass and accretion rate, the
viscous timescale is long ($\sim10$Myr) so the main evolutionary behaviour for
the first Myr of the disc's lifetime is truncation of the disc by
photoevaporation, with only modest changes effected by viscosity. We also
produce approximate synthetic observations of our models, finding substantial
emission from the flow which can explain the CO halo observed about IM Lup out
to $\geq1000$AU. Solutions that are consistent with the extent of the observed
CO emission generally imply that IM Lup is still in the process of having its
disc outer radius truncated. We conclude that IM Lup is subject to substantial
external photoevaporation, which raises the more general possibility that
external irradiation of the largest discs can be of significant importance even
in low mass star forming regions.

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The categories of this paper are: q-bio
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The categories of this paper are: nlin
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
2
The categories of this paper are: math
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org