Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Star formation in Perseus: II. SEDs, classification and lifetimes   Working with the submillimetre continuum map of the Perseus molecular cloud
(Hatchell et al. 2005), we aimed to determine the evolutionary stage of each
submm core in Perseus, and investigate the lifetimes of these phases. We
compile spectral energy distributions (SEDs) from 2MASS, Spitzer IRAC,
Michelle, IRAS, SCUBA and Bolocam data. Sources are classified
starless/protostellar on the basis of infrared and/or outflow detections and
Class I/Class 0 on the basis of Tbol, Lbol/Lsmm and F_{3.6}/F_{850}. In order
to investigate the dependence of these evolutionary indicators on mass, we
construct radiative transfer models of Class 0 sources. Of the submm cores,
56/103 (54%) are confirmed protostars on the basis of infrared emission or
molecular outflows. Of these, 22 are classified Class 1 on the basis of three
evolutionary indicators, 34 are Class 0, and the remaining 47 are assumed
starless. Perseus contains a much greater fraction of Class 0 sources than
either Taurus or Rho Oph. Comparing the protostellar with the T Tauri
population, the lifetime of the protostellar phase in Perseus is 0.25-0.67 Myr
(95% confidence limits). The relative lifetime of the Class 0 and Class 1
phases are similar. We find that for the same source geometry but different
masses, evolutionary indicators such as Tbol vary their value. It is therefore
not always appropriate to use a fixed threshold to separate Class 0 and Class I
sources. More modelling is required to determine the observational
characteristics of the Class 0/Class I boundary over a range of masses.

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The categories of this paper are: plasm-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
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The categories of this paper are: supr-con
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The categories of this paper are: nlin
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The categories of this paper are: chem-ph
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The categories of this paper are: physics
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin