Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The polarisation of afterglow emission reveals GRB jet structure   We numerically compute light and polarisation curves of gamma-ray burst
afterglows for various configurations of the jet luminosity structure and for
different dynamical evolutions. We especially consider the standard homogeneous
``top hat'' jet and the ``universal structured jet'' with power-law wings. We
also investigate a possible more physical variation of the ``top hat'' model:
the ``Gaussian jet''. The polarisation curves for the last two jet types are
shown here for the first time together with the computation of X-ray and radio
polarised fluxes. We show that the lightcurves of the total flux from these
configurations are very similar to each other, and therefore only very high
quality data could allow us to pin down the underlying jet structure. We
demonstrate instead that polarisation curves are a powerful means to solve the
jet structure, since the predicted behaviour of polarisation and its position
angle at times around the jet break are very different if not opposite. We
conclude that the afterglow polarisation measurements provide clear footprints
of any outflow energy distribution (unlike the lightcurves of the total flux)
and the joint analysis of the total and polarised flux should reveal GRBs jet
structure.

9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci