Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Oblique Shock Breakout from a Uniform Density Medium   The emergence of a shock from a medium with a free surface is an important
process in various astrophysical phenomena. It generates the first light
associated with explosions like supernovae and Gamma Ray Bursts. Most previous
works considered planar or spherical geometries, where the shock front is
parallel to the surface, and emerges simultaneously from all points. Here we
study the hydrodynamics of an oblique planar shock breaking out from the planar
surface of a uniform density ideal gas with adiabatic index $\gamma$. We obtain
an analytic solution to the flow as a function of the angle between the plane
of the shock and the surface $\beta$. We find steady state solutions (in a
frame moving with the intersection point of the shock and the surface) up to
some critical angle ($\beta_{max}=63.4$ degress for $\gamma=5/3$ and
$\beta_{max}=69.3$ degrees for $\gamma=4/3$). We show how this analytic
solution can be used in more complicated geometries where the shock is not
planar, giving the exact profile of the outermost breakout ejecta. We apply our
analytical results to a few realistic problems, such as underwater explosions,
detonation under the surface of an asteroid, or off center detonations in a
uniform sphere.

16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th