Radio observations of massive stars in the Galactic centre: The Arches
  Cluster
  We present high-angular-resolution radio observations of the Arches cluster
in the Galactic centre, one of the most massive young clusters in the Milky
Way. The data were acquired in two epochs and at 6 and 10 GHz with the Karl G.
Jansky Very Large Array (JVLA). The rms noise reached is three to four times
better than during previous observations and we have almost doubled the number
of known radio stars in the cluster. Nine of them have spectral indices
consistent with thermal emission from ionised stellar winds, one is a confirmed
colliding wind binary (CWB), and two sources are ambiguous cases. Regarding
variability, the radio emission appears to be stable on timescales of a few to
ten years. Finally, we show that the number of radio stars can be used as a
tool for constraining the age and/or mass of a cluster and also its mass
function.
