Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Major Mergers of Galaxy Haloes: Cuspy or Cored Inner Density Profile?   We present the results from a series of collisionless N-body simulations of
major mergers of galaxy dark matter haloes with density profiles having either
inner cusps or cores. Our simulations range from 2x10^5 to 10^7 particles,
allowing us to probe the phase-space distribution of dark matter particles in
the innermost regions (less than 0.005 virial radii) of cold dark matter
haloes, a subject of much recent debate. We find that a major merger of two
cored haloes yields a cored halo and does not result in a cuspy profile seen in
many cosmological simulations. This result is unchanged if we consider mergers
with parent mass ratios of 3:1 instead of 1:1. Mergers of a cuspy halo with
either a cored halo or a second cuspy halo of equal mass, on the other hand,
produce cuspy haloes with a slightly reduced inner logarithmic slope. Cuspy
haloes, once formed, therefore appear resilient to major mergers. We find the
velocity structure of the remnants to be mildly anisotropic, with a Maxwellian
velocity distribution near the centre but not in the outer portions of the
final haloes. Violent relaxation is effective only during the early phase of
mergers, with phase mixing likely to be the dominant relaxation process at late
times.

8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph