Dome C

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Astronomy from Antarctica
John W.V. Storey
Image Seth White
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Outline

• Orientation
• Dispelling the myths
• What makes a good observing site
• Optical/IR
• Terahertz
• But wait theres more
• The future

Image Patrik Kaufmann
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Outline

• Orientation
• Dispelling the myths
• What makes a good observing site
• Optical/IR
• Terahertz
• But wait theres more
• The future

Image Patrik Kaufmann
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Antarctica is very large

• USGS image

Geosciences Australia image
roughly twice the area of Australia.
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Contour map of Antarctica
Mount Kosciusko 2,228 m

• USGS image

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Potential observatory sites

• Dome A

• South Pole

• Vostok

• Average elevation of Antarctica 2300 m
• Average elevation of Asia 800 m

• Dome C

• USGS image

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Outline

• Orientation
• Dispelling the myths
• What makes a good observing site
• Optical/IR
• Terahertz
• But wait theres more
• The future

Image Patrik Kaufmann
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Top four myths about Antarctica

1. Its completely inaccessible
2. Your telescope will blow away
3. The conditions make it impossible to work
4. The violent snow storms will bury your telescope

Image Paolo Calisse
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Myth 1 Its completely inaccessible...
3.9 hrs
Dome C
Image Australian Antarctic Division
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Image John Storey
Already, Christchurch to South Pole...
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Image Michael Burton
...is faster than Sydney to Bremen...
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Image Michael Burton
...and the luggage allowance is 20 tonnes.
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In fact, isnt there a song called boats...
Image John Storey
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...and trains...
Image Karim Agabi
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...and planes...
Image John Storey
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...and things?
Image Geanpiero Venturi
Image Karim Agabi
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Myth 2 Your telescope will blow away...
http//www.geocities.com/
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Average wind speeds
Site Wind speed (m/s) Reference
Dome C (1984 1995) 2.7 Meyer Storey
South Pole 5.5 Mefford
Paranal 6.6 Hainaut
La Silla 4.6 Hainaut
La Palma 6.6 IAC
Mauna Loa 4.4 Barnes
Maidanak 2.1 Ehgamberdiev et al 2003
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Image John Storey
Myth 3 The conditions make it impossible to
work....
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Pressure altitude 3600 m Temperature -30oC
Image Karim Agabi
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Image Patrik Kaufmann
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Myth 4 The violent snow storms will bury the
telescope...
Image courtesy Keck Observatory, Mauna Kea.
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January 2003
November 2003
Dome C
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Prevailing wind
Annual precipitation 35 g/cm2 ie, 40 mm/year of
ice.
Image Karim Agabi
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Outline

• Orientation
• Dispelling the myths
• What makes a good observing site
• Optical/IR
• Terahertz
• But wait theres more
• The future

Image Patrik Kaufmann
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What makes a good observing site?
Low surface wind Low wind throughout
atmosphere No high level turbulence Low seismic
activity Very accessible Continuous observing
possible Stable climate
Clear High Dry Cold Clean Dark Low precipitation
Image Anna Moore
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Optical/Infrared
Image Karim Agabi
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Icecam
COBBER
The two experiments require no heat, run on a
lithium battery pack, and send data out via the
ARGOS satellite network.
Image John Storey
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ICECAM
Calibration LED
First winter-time stellar observations from Dome C
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ICECAM
Winter-time 2001 at Dome C data look encouraging!
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Aircraft contrails across Europe
http//www.eso.org/gen-fac/pubs/astclim/contrails/
NOAA-AVHRR-trail.jpg
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Summary of the global oceanic aerosol pattern
detected by polar-orbiting satellites between
July 1989 and June 1991

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Image Eric Fossat
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The infrared sky is extremely dark

• Kdark sky spectral brightness
• 220 ?Jy. arcsec-2 (mean)
• 120 ?Jy. arcsec-2 (median)
• This is 1-2 orders of magnitude lower than found
  at typical mid-latitude sites

Lawrence et al, PASA (2002)
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South Pole is 20 100 times darker than Siding
Spring
Phillips et al 1999
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SPIREX, the South Pole Infrared Explorer, was a
60 cm telescope with 1024 x 1024 InSb detector
array. SPIREX demonstrated the viability of IR
astronomy from Antarctica. SPIREX was a
collaboration between CARA, Ohio State
University, NOAO, Rochester I.T. and UNSW.
Image UNSW
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SPIREX image of star- formation in NGC6334
Burton et al, Astrophysical Journal, 542, 359,
(2000)
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Mid-infrared Comparison between South Pole and
other sites
Chamberlain et al 2000
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http//www.lightpollution.it/dmsp/
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Not good for astronomy
This would be a good place
Image NASA
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The Jet Stream
Dome C
South Pole
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Wind profiles
Mauna Kea
Dome C
Dome A
Balloon data (Aristidi et al, 2004)
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The effect of eliminating high-altitude turbulence
Turbulent layer high ? narrow field
Turbulent layer low ? wide field
10 100 times improvement in isoplanatic angle,
scintillation noise, and astrometric error.
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The effect of reducing high-altitude wind
Turbulent layer moves slowly

• Phase coherence times increased
• Required adaptive optics bandwidth decreases

10 100 times improvement in sensitivity of
interferometers and Adaptive Optics sensors.
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SODAR
Data Travouillon et al 2003
Image Geanpiero Venturi
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Peak Ground Acceleration up to 5m/s² 10
probability of exceedance in 50 years
South Pole is 30dB seismically quieter than Mauna
Kea
Source http//www.seismo.ethz.ch/GSHAP/
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• See less of sky
• Less dark time
• Ecliptic always low
• Aurorae
• Physical isolation in winter
• Diamond dust

The real disadvantages
Image Karim Agabi
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Terahertz astronomy
Image Seth White
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Water Vapour South Pole
Winter average PWV 250 ?m
(Chamberlin, 2000 Stark et al, 2001)
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Quartiles of PWV at three Sites
At each site, the year is divided into the best
and worst 6 -month periods. Bars show quartiles
of the PWV distribution at each site.
Lane, ASP Conference Series 141, 1998
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Sky Noise and opacity measurements at 350µm from
three sites
Peterson, Radford et al (in press).
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The AST/RO telescope has performed unique science
at South Pole for over a decade.
SPT, the South Pole Telescope, will be a 10m
diameter terahertz telescope.
Image AST/RO group
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Outline

• Orientation
• Dispelling the myths
• What makes a good observing site
• Optical/IR
• Terahertz
• But wait theres more
• The future

Image Patrik Kaufmann
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Cosmic Microwave Background studies tell us about
the early Universe.
Image NASA
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Experiments such as DASI and Boomerang, have
produced spectacular results.
Image DASI group
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Image Boomerang group
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These folk are astronomers, too.
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(No Transcript)
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Image http//icecube.wisc.edu
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Outline

• Orientation
• Dispelling the myths
• What makes a good observing site
• Optical/IR
• Terahertz
• But wait theres more
• The future

Image Patrik Kaufmann
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The French/Italian Concordia Station may be
open year-round from 2005.
Image Karim Agabi
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Site testing will be undertaken at Dome A, with
automated facilities
Image Camillo Calvaresi
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Image Geanpiero Venturi
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If we have to keep stopping to take pictures,
well never get to Dome A!
Image John Storey
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Vulcan South a search for planets around other
stars
Image Seth White
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Finding Planets via Transits
HD209458 observed with the Hubble Telescope

• Planet transit detection requires
• Continuous Observation
• Precision Photometry

? South Pole!
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Interferometry
Beam Combiner
Fringe
Delay Line
Image James Lloyd
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PILOT Pathfinder for an International Large
Optical Telescope.
A 2-metre optical/infrared telescope for Dome C.
EOST
Image Anglo-Australian Observatory
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Astronomers ultimately propose to construct
Extremely Large Telescopes of up to 100 metres
diameter.
Image European Southern Observatory
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It is fitting and beautiful that Antarctica, the
last place on our own earth to be fully explored,
turns out to be the best place from which to
discover new earths.
Image David A. Hardy
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Acknowledgements
IPEV - Institut Paul Emile Victor ARC -
Australian Research Council NSF- National
Science Foundation AAD - Australian Antarctic
Division
JACARA - Joint Australian Centre for
Astrophysical Research in Antarctica Italian
Programma Nazionale di Ricerche in
Antartide CARA - Center for Astrophysical
Research in Antarctica