ASKAP HI imaging of the galaxy group IC 1459
  We present HI imaging of the galaxy group IC 1459 carried out with six
antennas of the Australian SKA Pathfinder equipped with phased-array feeds. We
detect and resolve HI in eleven galaxies down to a column density of
$\sim10^{20}$ cm$^{-2}$ inside a ~6 deg$^2$ field and with a resolution of ~1
arcmin on the sky and ~8 km/s in velocity. We present HI images, velocity
fields and integrated spectra of all detections, and highlight the discovery of
three HI clouds -- two in the proximity of the galaxy IC 5270 and one close to
NGC 7418. Each cloud has an HI mass of $10^9$ M$_\odot$ and accounts for ~15%
of the HI associated with its host galaxy. Available images at ultraviolet,
optical and infrared wavelengths do not reveal any clear stellar counterpart of
any of the clouds, suggesting that they are not gas-rich dwarf neighbours of IC
5270 and NGC 7418. Using Parkes data we find evidence of additional extended,
low-column-density HI emission around IC 5270, indicating that the clouds are
the tip of the iceberg of a larger system of gas surrounding this galaxy. This
result adds to the body of evidence on the presence of intra-group gas within
the IC 1459 group. Altogether, the HI found outside galaxies in this group
amounts to several times $10^9$ M$_\odot$, at least 10% of the HI contained
inside galaxies. This suggests a substantial flow of gas in and out of galaxies
during the several billion years of the group's evolution.
