A 10-m Diameter Submillimeter-wave Telescope for the South Pole

1. A 10-m Diameter Submillimeter-wave Telescope for the South Pole Antony A. Stark A report to the Decadal Survey Committee of the National Academy of Sciences

2. Single-dish sub-mm in the next decade • Large focal-plane arrays will dramatically increase data rates of wide-field single dish sub-mm telescopes. • Fast, large-area surveys will enhance the effectiveness of interferometric arrays like MMA and SMA. • South Pole is the best site for a new single-dish telescope. 2

3. Unique capabilities of SP 10m Possible Key Projects • Deep (~ 1 mJy) large scale (many square degree) studies of Cosmic Far-Infrared Background Radiation • detection of thousands of protogalaxies • Studies of Cosmic Microwave Background Radiation at arcminute scales and high frequency (90 - 300 GHz) • Zel’dovich-Sunyaev velocity effect in distant clusters (z~1) • Survey of deeply embedded cloud cores throughout the Galaxy • Polarization studies of extended objects 3

4. Image sizes of sub-mm telescopes ~104 seconds ~102 seconds

5. SP 10m—New Opportunities • New optical design enables full exploitation of focal-plane arrays • shaped optics can increase field of view 20X • Superior sky noise and transparency enables deep observations in 350 m and 450 m windows • 200 m window [NII]

6. Site Testing • PWV at Pole is exceptionally small, stable and well-understood • Sub-mm skydips show South Pole best among all observatory sites • Reduced sky noise 7

7. Not usable Usable

8. Feasibility of Operations at Pole • AST/RO and VIPER have operated in winter • AST/RO acquired astronomical data 85% of time in winter 1998 • evolution to a full user-facility instrument • VIPER measured acoustic peak of CMBR during winter • Logistical requirements of 10m well within capacity of Modernized South Pole Station 9

9. AST/RO observations of NGC 6334

10. Phase A Design • Off-axis design provides low background, large flexible detector space • Choice of offset angles makes aberrations as small as on-axis • Proven primary mirror technology—carbon fiber reinforced truss with metal nodes, machined aluminum panels • titanium nodes? • Design will be refined and critiqued in Phase B

11. Model of SP 10m and SPSM

12. Budget • Proposed to NSF Office of Polar Programs as user-facility instrument • Total Capital Cost: $24.7M (1998), including logistical support and instrumentation • some costs already funded as part of South Pole redevelopment • International Partners (MPIfR, It. Ant., Leiden, UK) • Annual operating budget $5.6M (2008) • includes logistical costs routinely covered by U.S. Antarctic program • This is ~1/2 of current expenditure on Antarctic Astronomy 12

13. South Pole 10m • Best sub-mm sky • routine observations in 450 m and 350 m windows • 200 m window • exceptionally low sky noise • Arcminute-scale CMBR at high frequency, velocity S-Z effect • Effective use of large sub-mm focal plane arrays • Wide-field, fast, deep surveys for protogalaxies, cloud cores • Support and funding by U.S. Antarctic Program • If and only if there is a strong positive recommendation by astronomers