Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can magnetar spin-down power extended emission in some short GRBs?   Extended emission gamma-ray bursts are a subset of the `short' class of burst
which exhibit an early time rebrightening of gamma emission in their light
curves. This extended emission arises just after the initial emission spike,
and can persist for up to hundreds of seconds after trigger. When their light
curves are overlaid, our sample of 14 extended emission bursts show a
remarkable uniformity in their evolution, strongly suggesting a common central
engine powering the emission. One potential central engine capable of this is a
highly magnetized, rapidly rotating neutron star, known as a magnetar.
Magnetars can be formed by two compact objects coallescing, a scenario which is
one of the leading progenitor models for short bursts in general. Assuming a
magnetar is formed, we gain a value for the magnetic field and late time spin
period for 9 of the extended emission bursts by fitting the magnetic dipole
spin-down model of Zhang & Meszaros (2001). Assuming the magnetic field is
constant, and the observed energy release during extended emission is entirely
due to the spin-down of this magnetar, we then derive the spin period at birth
for the sample. We find all birth spin periods are in good agreement with those
predicted for a newly born magnetar.

1
The categories of this paper are: cs
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci