Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multiple relativistic outbursts of GRS 1915+105: radio emission and
  internal shocks   We present 5-GHz MERLIN radio images of the microquasar GRS 1915+105 during
two separate outbursts in 2001 March and 2001 July, following the evolution of
the jet components as they move outwards from the core of the system. Proper
motions constrain the intrinsic jet speed to be >0.57c, but the uncertainty in
the source distance prevents an accurate determination of the jet speed. No
deceleration is observed in the jet components out to an angular separation of
about 300mas. Linear polarisation is observed in the approaching jet component,
with a gradual rotation in position angle and a decreasing fractional
polarisation with time. Our data lend support to the internal shock model
whereby the jet velocity increases leading to internal shocks in the
pre-existing outflow before the jet switches off. The compact nuclear jet is
seen to re-establish itself within two days, and is visible as core emission at
all epochs. The energetics of the source are calculated for the possible range
of distances; a minimum power of 1-10 per cent of the Eddington luminosity is
required to launch the jet.

20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph