Exceptional terahertz transparency and stability above Dome A, Antarctica

• Published in: Publications of the Astronomical Society of the Pacific
• Main Authors: Yang, Huigen, Kulesa, Craig A., Walker, Christopher K., Tothill, Nicholas F. H. (R17058), Yang, Ji, Ashley, Michael C. B., Cui, Xiangqun, Feng, Longlong, Lawrence, Jon S., Luong-Van, Daniel M., McCaughrean, Mark J., Storey, John W., Wang, Lifan, Zhou, Xu, Zhu, Zhenxi
• Format: Article in Journal/Newspaper
• Language: English
• Published: U.S., University of Chicago Press 2010
• Subjects: 020102 - Astronomical and Space Instrumentation; Antarctic; Austral; The Antarctic; Antarc*; Antarctica
• Online Access: http://handle.uws.edu.au:8081/1959.7/557623; https://doi.org/10.1086/652276

We present the first direct measurements of the terahertz atmospheric transmission above Dome A, the highest point on the Antarctic plateau at an elevation of 4.1 km. The best-quartile atmospheric transmission during the Austral winter is 80% at a frequency of 661 GHz (453 μm), corresponding to a precipitable water vapor column of 0.1 mm. Daily averages as low as 0.025 mm were observed. The Antarctic atmosphere is very stable, and excellent observing conditions generally persist for many days at a time. The exceptional conditions over the high Antarctic plateau open new far-infrared spectral windows to ground-based observation. These windows contain important spectral-line diagnostics of star formation and the interstellar medium which would otherwise only be accessible to airborne or space telescopes.