Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Compressible flow in front of an axisymmetric blunt object: analytic
  approximation and astrophysical implications   Compressible flows around blunt objects have diverse applications, but
current analytic treatments are inaccurate and limited to narrow parameter
regimes. We show that the gas-dynamic flow in front of an axisymmetric blunt
body is accurately derived analytically using a low order expansion of the
perpendicular gradients in terms of the parallel velocity. This reproduces both
subsonic and supersonic flows measured and simulated for a sphere, including
the transonic regime and the bow shock properties. Some astrophysical
implications are outlined, in particular for planets in the solar wind and for
clumps and bubbles in the intergalactic medium. The bow shock standoff distance
normalized by the obstacle curvature is $\sim 2/(3g)$ in the strong shock
limit, where $g$ is the compression ratio. For a subsonic Mach number $M$
approaching unity, the thickness $\delta$ of an initially weak, draped magnetic
layer is a few times larger than in the incompressible limit, with
amplification $\sim ({1+1.3M^{2.6}})/({3\delta})$.

7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
16
The categories of this paper are: stat