Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spacecraft observations and analytic theory of crescent-shaped electron
  distributions in asymmetric magnetic reconnection   Supported by a kinetic simulation, we derive an exclusion energy parameter
$\cal{E}_X$ providing a lower kinetic energy bound for an electron to cross
from one inflow region to the other during magnetic reconnection. As by a
Maxwell Demon, only high energy electrons are permitted to cross the inner
reconnection region, setting the electron distribution function observed along
the low density side separatrix during asymmetric reconnection. The analytic
model accounts for the two distinct flavors of crescent-shaped electron
distributions observed by spacecraft in a thin boundary layer along the low
density separatrix.

22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
1
The categories of this paper are: cs
19
The categories of this paper are: eess
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph