Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Progenitor of the New COMPTEL/ROSAT Supernova Remnant in Vela   We show that (1) the newly discovered supernova remnant (SNR), GRO
J0852--4642/RX J0852.0--4622, was created by a core-collapse supernova of a
massive star, and (2) the same supernova event which produced the $^{44}$Ti
detected by COMPTEL from this source is probably also responsible for a large
fraction of the observed $^{26}$Al emission in the Vela region detected by the
same instrument. The first conclusion is based on the fact that the remnant is
currently expanding too slowly given its young age for it to be caused by a
Type Ia supernova. If the current SNR shell expansion speed is greater than
3000 km/s, a $15 M_\odot$ Type II supernova with a moderate kinetic energy
exploding at about 150 pc away is favored. If the SNR expansion speed is lower
than 2000 km s$^{-1}$, as derived naively from the X-ray data, a much more
energetic supernova is required to have occurred at $\sim250$ pc away in a
dense environment at the edge of the Gum nebula. This progenitor has a
preferred ejecta mass of $\le10 M_\odot$ and therefore, it is probably a Type
Ib or Type Ic supernova. However, the required high ambient density of $n_H \ge
100 cm^{-3}$ in this scenario is difficult to reconcile with the regional CO
data. A combination of our estimates of the age/energetics of the new SNR and
the almost perfect positional coincidence of the new SNR with the centroid of
the COMPTEL $ ^{26}$Al emission feature of the Vela region strongly favors a
causal connection. If confirmed, this will be the first case where both
$^{44}$Ti and $^{26}$Al are detected from the same young SNR and together they
can be used to select preferred theoretical core-collapse supernova models.

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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: stat
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an