Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Type Ia Supernovae in the First Few Days: Signatures of Helium
  Detonation versus Interaction   The mechanism for the early-phase blue and excessive emission within the
first few days, reported so far for a few type Ia supernovae (SNe Ia), has been
suggested to be interaction of the SN ejecta either with a non-degenerate
companion star or circumstellar media (CSM). Recently, another mechanism has
been suggested within the context of the He detonation-triggered SN scenario
(i.e., double detonation scenario or He-ignited violent merger), in which the
radioactive isotopes in the outermost layer of the SN ejecta produce the early
emission. In this paper, we investigate properties of the early-phase excessive
emission predicted by these different scenarios. The He detonation scenario
shows different behaviors in the early flash than the companion/CSM interaction
scenarios. Especially clear diagnostics is provided once the behaviors in the
UV and in the optical are combined. The spectra synthesized for the He
detonation scenario are characterized by the absorptions due to the He
detonation products, which especially develop in the decay phase. We further
expect a relation between the properties of the early-phase flash and those of
the maximum SN emission, in a way the brighter and slower initial flash is
accompanied by a more substantial effect of the additional absorptions (and
reddening). This relation, however, should be considered together with the
maximum luminosity of the SN, since the larger luminosity suppresses the effect
of the additional absorption. With these expected features, we address the
possible origins of the observed excessive early-phase emission for a few SNe.

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The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
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The categories of this paper are: atom-ph