Worldwide site comparison for submillimetre astronomy

Abstract

The most important limitation for ground-based submillimetre (submm) astronomy is the broad-band absorption of the total water vapour in the atmosphere above an observation site, often expressed as the Precipitable Water Vapour (PWV). A long-term statistic on the PWV is thus mandatory to characterize the quality of an existing or potential site for observational submm-astronomy. In this study we present a three-year statistic (2008-2010) of the PWV for ground-based telescope sites all around the world and for stratospheric altitudes relevant for SOFIA (Stratospheric Observatory for Far-infrared astronomy). The submm-transmission is calculated for typical PWVs using an atmospheric model. We present the absolute PWV values for each site sorted by year and time percentage. The PWV corresponding to the first decile (10%) and the quartiles (25%, 50%, 75%) are calculated and transmission curves between 150 μm and 3 mm for these values are shown. The Antarctic and South-American sites present very good conditions for submillimetre astronomy. The 350 μm and 450 μm atmospheric windows are open all year long whereas the 200 μm atmospheric window opens reasonably for 25 % of the time in Antarctica and the extremely high-altitude sites in Chile. Potential interesting new facilities are Macon in Argentinia and Summit in Greenland that show similar conditions as for example Mauna Kea (Hawaii). For SOFIA, we present in more detail transmission curves for different altitudes (11 to 14 km), PWV values, and higher frequencies (up to 5 THz). Though the atmosphere at these altitude is generally very transparent, the absorption at very high frequencies becomes more important, partly caused by minor species. In conclusion, the method presented in this paper could identify sites on Earth with a great potential for submillimetre astronomy, and guide future site testing campaigns in situ.

Accepted to A&A

References in corpus (5)

• GREAT/SOFIA atmospheric calibration
• Stability of the Submillimeter Brightness of the Atmosphere Above Mauna Kea, Chajnantor and the South Pole
• Site testing for submillimetre astronomy at Dome C, Antarctica
• The Optical/Infrared Astronomical Quality of High Atacama Sites. I. Preliminary Results of Optical Seeing
• Millimeter and sub-millimeter atmospheric performance at Dome C combining radiosoundings and ATM synthetic spectra

Cited by in corpus (9)

• Observations of the first electromagnetic counterpart to a gravitational wave source by the TOROS collaboration
• Evaluation of New Submillimeter VLBI Sites for the Event Horizon Telescope
• Global Distribution of Water Vapor and Cloud Cover--Sites for High Performance THz Applications
• 3.5-Year Monitoring of 225 GHz Opacity at the Summit of Greenland
• GW150914: First search for the electromagnetic counterpart of a gravitational-wave event by the TOROS collaboration
• First-generation Science Cases for Ground-based Terahertz Telescopes
• Corral Framework: Trustworthy and Fully Functional Data Intensive Parallel Astronomical Pipelines
• SABOCA 350-micron and LABOCA 870-micron dust continuum imaging of IRAS 05399-0121: mapping the dust properties of a pre- and protostellar core system
• TOROS Optical follow-up of the Advanced LIGO-VIRGO O2 second observational campaign