The Fuelling of Star Formation in Primordial Galaxies

A central cornerstone of our model of galaxy formation is how typical galaxies acquire their gas and the mechanisms by which the gas fuels star formation in these galaxies. Newly forming galaxies are usually so far away that the light we detect from them has taken several billion years to reach us, so that we are essentially peering into the most distant corners of the Universe and into the past, when the Universe was very young and just starting to form stars and galaxies. The light from these baby galaxies is also typically very faint as they are so far away; but in rare instances, a system's light can be magnified and stretched artificially by intervening matter by a process called gravitational lensing. A handful of normal galaxies in formation which have been gravitationally lensed in this way have been found serendipitously by sky surveys.

This project will allow us to dissect the gas distribution in one of these very distant star-forming galaxies on unprecedentedly small scales of ~0.02'' for such a distant galaxy (corresponding to a physical scale of about 200 pc; for reference, our Milky Way Galaxy is about 30 kpc across). These observations will be among the first that the new Atacama Large Millimeter Array (ALMA) will perform in its ``early science'' mode, and provide a showcase of the facility's capabilities. ALMA is an array of 66 telescopes situated in the Atacama desert in Chile that will collect and combine the radio waves from our astronomical source to construct images that are comparable to those that would be obtained with a hypothetical giant telescope 14 km in diameter!

The combination of ALMA's unique sensitivity and spatial resolution applied to this highly magnified system will allow us to address questions which are science drivers of the ALMA and facilities of the future: yielding insights into the kinematics of the interstellar medium in a normal, young galaxy seen 12 billion years ago.

Astronomical research has a long history as an ambassadorial science, with an
established reputation for engaging the public, and capturing the imagination
of the young. The recent success of public engagement television shows such as the BBC's "Stargazing Live" are clear evidence of this. Often, news of breakthrough astronomical results are the first 'taste' of real scientific
research that school pupils are exposed to. This can be incredibly beneficial
for inspiring and encouraging primary and secondary school students to enrol
in mathematics and physics in higher education - subjects of vital importance
to the economy, since they underpin every aspect of industry. In addition, the
health of the future scientific research climate in the UK depends on a steady
stream of highly motivated young people to study at the PhD level and to
participate in post-doctoral research. The standing of the UK's scientific
research profile on the international scene is intimately linked with the
economic well-being of the country, and so policy makers will have a vested
interest in my outreach strategy.

Therefore, aside from the extragalactic astronomical research community who
will be interested in (and use) the results generated and analysis performed
during my project, the main beneficiaries of my proposed research would be the
general public. My project contains several elements that will capture the
imagination, and I will convey these in press releases, public talks and
presentations and the like (see Pathways To Impact). For example, the public
will find it particularly interesting that we will be mapping the raw material
for star formation in a galaxy that exists just a few billion years after the
Big Bang. The public will also be fascinated by the technological developments
that allow us to perform such observations - namely the powerful ALMA
interferometer; I will include this in my outreach. The public will benefit by
being educated in this emerging area of research, and in the longer term, this
engagement will benefit the society for the reasons given above.

Finally, the UK is heavily invested in ALMA via the European Southern
Observatory, and, given the importance of explaining how tax payer's money is
spent and used (especially in the present economic climate) conveying the
scientific results in a way that is understandable by the layperson, performs
the dual role of educating and inspiring the public, whilst satisfying the
need to be transparent and financially accountable.

This project will deliver results on a timescale of 1-2 years, with clear and
achievable goals culminating in several academic publications and data
products; these will immediately be available to the scientific community in
the full spirit of open access and collaboration. Public engagement activities
will necessarily be on an equivalent timescale, with press releases (etc.)
timed to coincide with publication.