Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Injection and Acceleration of Electrons at A Strong Shock: Radio and
  X-ray Study of Young Supernova 2011dh   In this paper, we develop a model for the radio and X-ray emissions from Type
IIb Supernova (SN IIb) 2011dh in the first 100 days after the explosion, and
investigate a spectrum of relativistic electrons accelerated at a strong shock
wave. The widely-accepted theory of the particle acceleration, so-called
diffusive shock acceleration (DSA) or Fermi mechanism, requires seed electrons
with modest energy with gamma ~ 1 - 100, and little is known about this
pre-acceleration mechanism: We derive the energy distribution of relativistic
electrons in this pre-accelerated energy regime. We find that the efficiency of
the electron acceleration must be low, i.e., epsilon_e <~ 0.01 as compared to
the conventionally assumed value of epsilon_e ~ 0.1. Furthermore, independently
from the low value of epsilon_e, we find that the X-ray luminosity cannot be
attributed to any emission mechanisms suggested so far as long as these
electrons follow the conventionally-assumed single power-law distribution. A
consistent view between the radio and X-ray can only be obtained if the
pre-acceleration injection spectrum peaks at gamma ~ 20-30 and then only a
fraction of these electrons eventually experience the DSA-like acceleration
toward the higher energy -- then the radio and X-ray properties are explained
through the synchrotron and inverse Compton mechanisms, respectively. Our
findings support the idea that the pre-acceleration of the electrons is coupled
with the generation/amplification of the magnetic field.

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The categories of this paper are: dg-ga
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int