Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variable accretion and emission from the stellar winds in the Galactic
  centre   We present numerical simulations of stellar wind dynamics in the central
parsec of the Galactic centre, studying in particular the accretion of gas on
to Sgr A*, the super-massive black hole. Unlike our previous work, here we use
state-of-the-art observational data on orbits and wind properties of individual
wind-producing stars. Since wind velocities were revised upwards and non-zero
eccentricities were considered, our new simulations show fewer clumps of cold
gas and no conspicuous disc-like structure. The accretion rate is dominated by
a few close `slow wind stars' v_w < 750 km/s, and is consistent with the Bondi
estimate, but variable on time-scales of tens to hundreds of years. This
variability is due to the stochastic in-fall of cold clumps of gas, as in
earlier simulations, and to the eccentric orbits of stars. The present models
fail to explain the high luminosity of Sgr A* a few hundred years ago implied
by Integral observations, but we argue that the accretion of a cold clump with
a small impact parameter could have caused it. Finally, we show the possibility
of constraining the total mass-loss rate of the `slow wind stars' using near
infra-red observations of gas in the central few arcseconds.

34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph