The Atacama Large Millimeter/submillimeter Array (ALMA) is currently being constructed at the 5000 m Chajnantor plateau in the Chilean Andes. ALMA has been designed and is being built to deliver transformational science in the millimeter and submillimeter regime for many years to come. We briefly describe the project status and timeline. We discuss which niches in millimeter/ submillimeter astronomy will remain open for a possible facility in Antarctica.

Star formation is the fundamental cosmic process that determines the evolution of ordinary baryonic matter in the Universe. Because stars form from cold, dense, and obscured cores in interstellar molecular clouds, star formation investigations require observations in the infrared to radio wavelength portions of the electromagnetic spectrum. The high elevations and dry conditions at sites on the Antarctic plateau provide the darkest sky and best transparency available from any ground-based location. I present an overview of unique observational opportunities in the general area of star and planet formation studies from Antarctica. A 2 to 3 meter diameter mid-IR telescope optimized for wide-field imaging provides the most exciting near-term opportunities for a program of star formation studies.

The early stages of the star formation process are closely related to the condition of the parent interstellar medium, in particular to the heating/cooling balance, which itself is a function of ambient conditions. Important questions such as dust abundance, size distribution, temperature distribution, fraction of molecular gas, fraction of dense gas, gas surface density and total amount of gas and dust require separation of metallicity and radiation effects. The Magellanic Clouds provide an ideal laboratory to carry out such studies almost under “controlled conditions”. Although they are prominent targets for space observatories (Spitzer, Herschel), an important role remains for large groundbased facilities, such as a 25 m class sub-millimeter telescope on Dome C. Large-scale mapping at high resolution should be carried out both in the continuum and in various lines, fully complementing other groundbased and spacebased observing programs.

Over the last decade observations at submillimetre (submm) wavelengths, with their unique ability to trace molecular gas and dust, have attained a central role in our exploration of nearby as well as distant galaxies. Even so, due to the limited sensitivity and angular resolution of current submm single-dish telescopes only the most luminous objects have been uncovered at high redshifts, with interferometric follow-up observations succeeding in resolving the dust and gas reservoirs at ~0.3-1'' resolution in only a few cases. The coming years will witness a drastic improvement in the current situation, thanks to the arrival of a new suite of powerful submm telescopes (single-dish and interferometers) with an order of magnitude improvement in sensitivity and resolution. In this overview I outline some of the major scientific advances that we expect to make with these ground-breaking facilities.

COCHISE is a 2.6 meter millimetric telescope, mainly devoted to cosmological observations, located at Concordia. In this paper we report on the installation phases and preliminary operations performed with this instrument. At present, COCHISE is the largest telescope located at Concordia, for that reason it represents a pathfinder for future telescopes.

We present model calculations of the atmospheric transmission for DOME C in Antarctica for frequencies up to 10 THz (30 μm) using the forward model MOLIERE-5. Measurements of precipitable water vapor (pwv), obtained by the SUMMIT radiometer installed at the Concordia station during 2008 and working at a wavelength of 200 μm, are translated into atmospheric transmission using MOLIERE. Quartiles of transmission, calculated from 200 μm data are extrapolated to 350 μm and compared to the CCAT (Cornell-Caltech Atacama Telescope) site in Chile. It turns out that for 25% of the time at DOME C (CCAT), the transmission is around 20% (5%) at 200 μm. This corresponds to a pwv of 0.18 mm for DOME C. At 350 μm, for 50% of time at DOME C (CCAT) the transmission is around 55% (25%). This corresponds to a pwv of 0.22 mm for DOME C. These results show that DOME C is one of the best observing sites on Earth for submm-astronomy with respect to high atmospheric transmission over long time periods.

We present preliminary results of the measurements of sky transparency conducted at Dome C during the winter 2008. Using MOLIERE modeling, we estimate a low precipitable water vapour content above Concordia station, which is very promising for future submillimetre wave observations on the Antarctic Plateau.

As science makes progress, proposing new discoveries every day, it is more and more interesting for the astronomical world to perform sub-millimeter observations from very suitable terrestrial sites, due to the purity of the air as well as to other environmental factors. A site with these characteristics has been identified in the area of the DOME C in the South Pole.
The problems, both technical and logistic, that the installation of a radio antenna in the South Pole requires, are easily understandable.
Proceeding at the same rate as the progress of science, also the technological and industrial capacities improve, so that the problems that the realization of a sub-millimiter Observatory in the South Pole implies, can be overcome.
This is a summary of a Preliminary Feasibility Study of the AST (Antarctic Sub-millimeter Telescope) Radioantenna that is intended to be installed at Dome C.

We summarize the current discussions towards astronomical time-series observations at Dome C and emphasize some near-future projects. We define time-series as the continuous process of data taking that takes advantage of the unique time windows and observing conditions at Dome C. We emphasize that most of the current approaches to time-series astrophysics require a dedicated flux collector. In addition, some specific scientific topics may proceed with significant fractions of time on multi-purpose facilities. We consider only on those ideas and projects that were presented at least once during the various ARENA workshops and conferences. Topics of solar science are not considered in detail here.

So as to prepare future observations of terrestrial extrasolar planets liable to shelter life, we attempt to detect the life on the Earth seen as a dot. We use the Moon Earthshine, in which any place reflects the totality of the enlightened part of Earth facing the Moon. Observing from OHP and from ESO, we detected terrestrial chlorophyll in the near infrared, the so-called Vegetation Red Edge, and this detection is larger when forests are present than when an ocean is mainly visible from the Moon. Only if observations are made from a high latitude location, and at some moments in the year, Earthshine can be observed during a large part of the day. During these long observing windows, different “landscapes" are facing the Moon. So the Earthshine corresponding to various parts of our Earth could be studied. Preliminary testing observations have been made at Concordia since the first winterover campaign and the LUCAS experiment has been set up.

ASTEP South is an Antarctic Search for Transiting ExoPlanets in the South pole field, from the Concordia station, Dome C, Antarctica. The instrument consists of a thermalized 10 cm refractor observing a fixed 3.88° × 3.88° field of view to perform photometry of several thousand stars at visible wavelengths (700–900 nm). The first winter campaign in 2008 led to the retrieval of nearly 1600 hours of data. We derive the fraction of photometric nights by measuring the number of detectable stars in the field. The method is sensitive to the presence of small cirrus clouds which are invisible to the naked eye. The fraction of night-time for which at least 50% of the stars are detected is 74% from June to September 2008. Most of the lost time (18.5% out of 26%) is due to periods of bad weather conditions lasting for a few days (“white outs”). Extended periods of clear weather exist. For example, between July 10 and August 10, 2008, the total fraction of time (day+night) for which photometric observations were possible was 60%. This confirms the very high quality of Dome C for nearly continuous photometric observations during the Antarctic winter.

ICE-T (International Concordia Explorer Telescope) is a double 60 cm f/1.1 photometric robotic telescope, on a parallactic mount, which will operate at Dome C, in the long Antarctic night, aiming to investigate exoplanets and activity of the hosting stars. Antarctic Plateau site is well known to be one of the best in the world for observations because of sky transparency in all wavelengths and low scintillation noise. Due to the extremely harsh environmental conditions (the lowest average temperature is –80°C) the criteria adopted for an optimal design are really challenging. Here we present the strategies we have adopted so far to fulfill the mechanical and optical requirements.

SIAMOIS is a ground-based asteroseismology project, to pursue velocity measurements from the Dome C Concordia station in Antarctica. Dome C appears to be the ideal place for ground-based asteroseismic observations as it is capable of delivering a duty cycle as high as 87% during the three-month long polar night. This high duty cycle, a crucial point for asteroseismology, is comparable to the best space-borne observations.
We present the quality of the SIAMOIS project, that yields to its selection as top priority by the working group of ARENA dedicated to “Time series observations from Dome C”. We show that, after CoRoT, SIAMOIS proposes a large scientific case, that extends the pioneering work and great discoveries of CoRoT. We depict a few important ingredients of the project: full automation, space-like philosophy, and compatibility with the current facilities at the Concordia station. SIAMOIS has no real competitor before at least 2016/2017, and can be considered as a pathfinder for many important issues concerning astronomical observations at Dome C.

We summarize the results of the Cosmic Microwave Background (CMB) working group of the ARENA project. The focus has been on precision measurements of CMB polarization (looking for the echoes of cosmological inflation) and high angular resolution CMB measurements (looking for Sunyaev Zeldovich effect in distant clusters of Galaxies, to probe the evolution of the Universe, Dark Matter and Dark Energy). For both projects the Dome C site represents the best choice worldwide.

The quest for the B-modes in the CMB polarization is one of the main challenges of modern cosmology as it would allow to give sharp constraints on the inflationary period. One of the main challenges of B modes detection is the treatment of systematic errors. Comparison of observations subject to different systematics is crucial. Interferometers offer such an alternative to imagers. However, to obtain the required sensitivity, a very large number of baselines is needed, which is extremely difficult to achieve with heterodyne interferometry. Bolometric interferometry copes with this problem using a new technique: the interference pattern produced by a few hundred horns is imaged on a bolometer array, and a time modulation of phase shifts insures the separation of visibilities while coherently adding redundant ones. The QUBIC collaboration proposes to build such an instrument.

For submillimeter astronomy, particularly at 200$\,\mu$m, the ARENA working group has proposed a 25 m telescope at the Concordia station on Dome C. Issues related to this suggestion are reviewed.

The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) has recently conducted an extragalactic submillimetric survey of the Chandra Deep Field South region of unprecedented size, depth, and angular resolution in three wavebands centered at 250, 350, and 500 µm. BLAST wavelengths are chosen to study the Cosmic Infrared Background near its peak at 200 µm. We find that most of the CIB at these wavelengths is contributed by galaxies detected at 24 µm by the MIPS instrument on Spitzer, and that the source counts distribution shows a population with strongly evolving density and luminosity. These results anticipate what can be expected from the surveys that will be conducted with the SPIRE instrument on the Herschel space observatory.

The science case for FIR/Submm surveys of the extragalactic sky that might be carried out with a large sub-millimetric telescope on a very dry site is briefly reviewed. Some of the main questions concerning the formation and evolution of galaxies, making up the Cosmological IR Background, and the formation of Active Galactic Nuclei and quasars are outlined and opportunities to exploit such a unique facility are discussed. The synergy of simultaneous sub- millimetric and far-IR surveys will be discussed.

The excellent observing conditions at Concordia station offer an outstanding opportunity to carry out sensitive FIR/SMM surveys of the extragalactic sky in order to resolve the Cosmic Background at these wavelengths. We outline the main standing questions about the formation and evolution of galaxies making up the FIR/SMM Cosmic Background and discuss how single-dish observations with either a 12-m or a 25-m antenna at Concordia would help in answering them.

Cosmic Microwave Background observations became the tool to probe the the first events of cosmic history. After WMAP data releases, galactic and extragalactic foregrounds are perceived as the main limiting uncertainity for the near-future search for the B-mode polarization inprints from the inflationary era, either through satellites or ground-based experiments like Brain at Dome-C. A combination of technology, scanning strategy and above all, accurate knowledge of polarized foregrounds will be necessary for an optimal mapping of B-mode CMB Polarization. In addition, the search for a better understanding of the galactic foregrounds will provide unprecedented knowledge on the Milky Way structure and star formation.