Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Protostar in the massive Infrared Dark Cloud IRDC18223-3   At the onset of high-mass star formation, accreting protostars are deeply
embedded in massive cores made of gas and dust. Their spectral energy
distribution is still dominated by the cold dust and rises steeply from near-to
far-infrared wavelengths. The young massive star-forming region IRDC18223-3 is
a prototypical Infrared-Dark-Cloud with a compact mm continuum core that shows
no protostellar emission below 8mum. However, based on outflow tracers, early
star formation activity was previously inferred for this region. Here, we
present recent Spitzer observations from the MIPSGAL survey that identify the
central protostellar object for the first time at 24 and 70mum. Combining the
mid- to far-infrared data with previous mm continuum observations and the upper
limits below 8mum, one can infer physical properties of the central source. At
least two components with constant gas mass M and dust temperature T are
necessary: one cold component (~15K and ~576M_sun) that contains most of the
mass and luminosity, and one warmer component (>=51K and >=0.01M_sun) to
explain the 24mum data. The integrated luminosity of ~177L_sun can be used to
constrain additional parameters of the embedded protostar from the turbulent
core accretion model for massive star formation. The data of IRDC18223-3 are
consistent with a massive gas core harboring a low-mass protostellar seed of
still less than half a solar mass with high accretion rates of the order
10^-4M_sun/yr. In the framework of this model, the embedded protostar is
destined to become a massive star at the end of its formation processes.

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The categories of this paper are: econ
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: nlin
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg