Emonts et al. (2014) present a CO(1-0) survey for cold molecular gas in a
representative sample of 13 high-z radio galaxies (HzRGs) at 1.4 < z < 2.8,
using the Australia Telescope Compact Array (ATCA). They detect CO(1-0)
emission associated with five sources: MRC 0114-211, MRC 0152-209,
MRC 0156-252, MRC 1138-262 (Spiderweb Galaxy) and MRC 2048-272. Intriguingly,
in all five sources the CO(1-0) emission is found up to tens of kpc from the
host galaxy. In several cases the CO(1-0) traces a large reservoir of cold
gas at the tip of the radio source, which suggests that jet-induced feedback
can trigger the formation of cold molecular gas in the halo environment of
high-z radio galaxies. These results show that the compact hybrid array
configurations of the ATCA are sensitive to tracing the most widespread and
possibly diffuse molecular gas in the Early Universe, something that cannot
be efficiently done by any other radio telescope. The image shows CO(1-0)
emission (in blue) spread across the inter-galactic medium of the massive
Spiderweb Galaxy at z=2.16 (high-resolution follow-up, as shown by the
line-profile on the top-right, is in progress).
ATNF
Science Highlights from refereed publications during 2014.
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