Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A unified picture for low-luminosity and long gamma-ray bursts based on
  the extended progenitor of llgrb 060218/SN 2006aj   The relation between long gamma-ray bursts (LGRBs) and low-luminosity GRBs
(llgrbs) is a long standing puzzle -- on the one hand their high energy
emission properties are fundamentally different, implying a different gamma-ray
source, yet both are associated with similar supernovae of the same peculiar
type (broad-line Ic), pointing at a similar progenitor and a similar explosion
mechanism. Here we analyze the multi-wavelength data of the particularly
well-observed SN 2006aj, associated with llgrb 060218, finding that its
progenitor star is sheathed in an extended ($>100R_\odot$), low-mass ($\sim
0.01M_\odot$) envelope. This progenitor structure implies that the gamma-ray
emission in this llgrb is generated by a mildly relativistic shock breakout. It
also suggests a unified picture for llgrbs and LGRBs, where the key difference
is the existence of an extended low-mass envelope in llgrbs and its absence in
LGRBs. The same engine, which launches a relativistic jet, can drive the two
explosions, but, while in LGRBs the ultra-relativistic jet emerges from the
bare progenitor star and produces the observed gamma-rays, in llgrbs the
extended envelope smothers the jet and prevents the generation of a large
gamma-ray luminosity. Instead, the jet deposits all its energy in the envelope,
driving a mildly relativistic shock that upon breakout produces a llgrb. In
addition for giving a unified view of the two phenomena, this model provides a
natural explanation to many observed properties of llgrbs. It also implies that
llgrbs are a viable source of the observed extra-galactic diffuse neutrino flux
and that they are promising sources for future gravitational wave detectors.

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The categories of this paper are: physics
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The categories of this paper are: nucl-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: math
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
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The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org