Scientific rationale

Submillimetre (submm) astronomy is the prime technique to unveil the birth and early evolution of a broad range of astrophysical objects of the “cold Universe”. Submm continuum observations are particularly powerful to measure the luminosities, temperatures and masses of cold dust emitting objects. Examples of such objects include star-forming clouds in our Galaxy, prestellar cores and deeply embedded protostars, proto-planetary disks around young stars, as well as nearby starburst galaxies and dust-enshrouded high-redshift galaxies in the early Universe.

 A major obstacle to carry out submm observations from ground is the atmosphere. Astronomical observations in the FIR/submm/THz spectral bands (e.g. 200, 350, 450 µm) can only be achieved from cold, dry and stable sites with ground-based telescopes or from space to overcome the atmosphere opacity and instability that are mainly due to water vapour absorption and fluctuations in the low atmosphere. Chile currently offers the best accessible (all-year long) sites on Earth, where the precipitable water vapour (PWV) content is often less than 1 mm. Chile hosts the European facilities for submm/mm astronomy such as ESO VLT, APEX and the Chajnantor plateau (5100m) will be the ALMA site. However, THz/submm are only possible with PWV drops below 0.5 mm, which occurs less than 25% of wintertime at the ALMA site. At longer term, and particularly if global warming severely restricts the 200-350-450-µm windows on Chilean sites, Antarctica conditions with less than 0.2 mm PWV, could offer an exciting and unique alternative for ground-based THz/submm astronomy. This is an attractive opportunity for the 200-µm windows, especially, which are normally explored with Space telescopes (e.g. Herschel).

Objective

The workshop will be entitled "Submillimetre/TeraHertz/Far-infrared Astronomy from Antarctica: Toward a large single-dish telescope at Dome C ?" and will be a *science driven* meeting. It will be organised within the framework of ARENA under the activity: NA5.2, New windows in
the FIR/submm (150-500 microns).

Which science? As a primary goal, the workshop will identify unique scientific cases for which submm/THz observations with large (ground-based) telescopes are essential to make a big step in understanding the cold Universe (proto-planetary disk, star formation, high-redshift proto-galaxies and cosmology).

Which instrument and telescope? The workshop will therefore aim to discuss the possibility and the feasibility of installing a large (>10 m) single-dish antenna at Dome C and whether this telescope should be a dedicated instrument or an international facility. Logistics and cost vs. benefit in comparison with Chajnantor site will also be discussed.

Is Dome C the best site? Present knowledge of the atmospheric transmission in the FIR/submm windows and future site testing campaigns will be presented.

Conclusions 
of the workshop will define a roadmap for submm astronomy at Dome C. An ARENA report will then be prepared with all the participants.