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Radio-Millimeter-Submillimeter
The next generation of radio telescopes beyond ALMA will exploit phased-array technology and
a new generation of fast digital correlators to make possible radio telescope arrays with thousands of
linked antennae, with collecting areas approaching a square kilometer, and extending up to thousands of
kilometers. Retrofitting existing telescopes with focal plane arrays, will (and already has) enabled gains
of orders of magnitude in mapping speed. The most ambitious of these projects, the SKA, was co-ranked
as the highest priority large facility (with the E-ELT) for the coming decade in the European Astronet
Decadal Survey, and it has strong additional support from Australia and South Africa, the candidate sites
for the SKA.
The SKA project encompasses the development of the next generation radio capability to operate
in the meter to centimeter wavelength range. SKA technology development was a key part of the RMS
program endorsed by the AANM report; significant NSF funding ($12M) became available only in 2007.
As noted in the report of the AUI Committee on the Future of U.S. Radio Astronomy 8 and as defined in
the report of the RMS panel, the SKA concept is likely to be fulfilled by separate facilities delivering
huge increases in collecting area via different technical approaches appropriate to three separate
wavelength ranges, referred to as SKA-low (1-3 meters wavelength), SKA-mid (3-100 cm wavelength)
and SKA-high (0.6-3.0 cm wavelength). Concept and technology development for the SKA is being
undertaken by the international SKA consortium including some 55 institutions in 19 countries. Many of
the areas of technology development recommended in the RMS report are crucial steps along the road to
achievement of the SKA.
The dramatic increase in scientific capability delivered by SKA is directly reflected in the scope,
complexity, and technical challenge of SKA concept development. At the present time, the detailed path
to construction of any of the three SKA facilities is not clear. However, continued steady development of
technology will lead to the next generation of radio facilities.
The HERA program, a project that was highly ranked by the RMS-PPP and included by the
committee in its list of compelling cases for a competed mid-scale program at NSF, provides a
development pathway for the SKA-low facility. Progress on development of the SKA-mid pathfinder
instruments, the Allen Telescope Array in the U.S., the MeerKAT in South Africa and the ASKAP in
Australia, and in new instruments and new observing modes on the existing facilities operated by NRAO
and NAIC will provide crucial insight into the optimal path towards a full SKA-mid. It is natural for the
U.S. to build on its long successful heritage with the EVLA, GBT and VLBA in further developing the
capabilities leading towards the SKA-high. It is primarily through technology development, that the U.S.
can remain an active partner in the concept development of the next generation meter-to-centimeter
wavelength radio facilities through the international SKA collaboration.
Particle Astrophysics and Gravitation
Design efforts in the U.S. and in Europe for the next generation TeV Cherenkov telescope, AGIS
and CTA respectively, are underway and follow a recent worldwide explosion of activity in gamma-ray
astrophysics, with the U.S.-led Fermi Gamma-ray Space Telescope (FGST) in space and a host of TeV
Cherenkov telescopes on the ground (VERITAS, HESS, MAGIC, Milagro, CANGAROO and HEGRA).
The proposed new instruments would increase sensitivity and field of view by an order of magnitude. As
the two designs have similarities and complementarity (including the location of VERITAS and HESS in
different hemispheres), opportunities for collaboration exist and discussions are underway. This is yet
another example in which common scientific interests, current capability, and design complementarity
make collaboration not only a means of reducing cost to each partner, but a way of creating a more
capable observatory.
8 Report is available at http://www.aui.edu/pr.phpid=20081003. Accessed May 2010.
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