Antarctic site promises to open a new window on the cosmos December 12, 2016 Please Register or Log in to view the hidden image! Equipment deployed at Dome A in Antartica, a site as high as Maunakea and 10 times drier, showed that it would be an ideal location for astronomy at terahertz radio frequencies. Credit: Xue-Fei Gong/Purple Mountain Observatory Antarctica might be one of the most inhospitable regions on the planet, but it is a mecca for astronomers. Its cold, dry air enables observations that can't be done elsewhere on Earth. The South Pole has hosted telescopes for decades. Now, researchers are eyeing a new location - Dome A, which offers a unique opportunity to study the universe at little-explored terahertz radio frequencies. Read more at: http://phys.org/news/2016-12-antarctic-site-window-cosmos.html#jCp extract: As a reward for these herculean efforts, scientists can access a type of light known as terahertz radiation, which has frequencies higher than 1 trillion hertz (1,000 times greater than the frequency used by cell phones). This radiation comes from cold clouds of interstellar gas and dust. By studying it, we can gain new insights into the origins of stars and galaxies. Read more at: http://phys.org/news/2016-12-antarctic-site-window-cosmos.html#jCp
http://www.nature.com/articles/s41550-016-0001 Terahertz and far-infrared windows opened at Dome A in Antarctica Abstract The terahertz and far-infrared band, ranging from approximately 0.3 THz to 15 THz (1 mm to 20 μm), is important for astrophysics as it hosts the peak of the thermal radiation of the cold component of the Universe as well as many spectral lines that trace the cycle of interstellar matter1–8. However, water vapour makes the terrestrial atmosphere opaque to this frequency band over nearly all of the Earth’s surface9. Early radiometric measurements10 below 1 THz at Dome A (80° 22′ S, 77° 21′ E), the highest point of the cold and dry Antarctic ice sheet, suggest that this site may offer the best possible access for ground-based astronomical observations in the terahertz and far-infrared band. To fully assess the site conditions and to address the uncertainties in radiative transfer modelling of the atmosphere, we carried out measurements of atmospheric radiation from Dome A with a Fourier transform spectrometer, spanning the entire water vapour pure rotation band from 20 μm to 350 μm. Our measurements reveal substantial transmission in atmospheric windows throughout the whole band. By combining our broadband spectra with data on the atmospheric state over Dome A, we set new constraints on the spectral absorption of water vapour at upper tropospheric temperatures, which is important for accurate modelling of the terrestrial climate. We find that current spectral models significantly underestimate the H2O continuum absorption. more at link....
