Transcript Radio Astronomy Projects

Astronomy Beyond 2009
Large Radio Astronomy Projects
Ron Ekers, CSIRO
IYA Closing Ceremony, Padua, Italy
10 Jan 2010
Outline
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From Galileo to Jansky
Astronomy at radio wave lengths
Impact of new technology
Science Opportunities
– Examples of a few key experiments with some of the proposed facilities
 Future Facilities
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EVLA
ATA, GMRT
ALMA
LOFAR, MWA
Focal Plane Arrays
» Parkes, Arecibo, ASKAP, Apertif (cm
» SPT… (mm)
– SKA
10 Jan 2010
R D Ekers
2
Galileo Galilei – 1609
 Galileo builds a telescope and he sees the moons of
Jupiter.
“Four planets, never seen since the beginning of the World
right up to our day”
3
Galileo’s discoveries
 Used an instrument built for other purposes
 Unexpected discoveries
– Except for phases of Venus
 But directly relevant to current theories of the Sun centered
model of the Universe
– Copernicus, Kepler
 Galileo had no doubt that Copernicus and Kepler were
right, yet he continued to search for evidence in favour of
this model in the hope of converting the establishment,
which still clung to the traditional view of an Earth-centred
universe.
10 Jan 2010
R D Ekers
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323 years later
 Mankind had its next new view of the Universe
 The discovery of a new kind of telescope opens a
new window on the Universe using radio waves
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Karl Jansky
Bell Telephone Laboratory 1932
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Discoveries made with new
instruments
 Used a telescope built for other purposes
– Communications
 Completely unexpected discovery
 No existing theoretical framework
– Required a universe with non-thermal phenomena
10 Jan 2010
R D Ekers
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The 4 Nobel prizes in
Radio Astronomy
 Cosmic Microwave Background (1965)
– Nobel prize to Penzias and Wilson
 CMB spectrum & anisotropy (1989)
– COBE satellite
– John Mather & George Smoot
 Discovery of pulsars (1967)
– radio pulsations from neutron stars
– Tony Hewish (Jocelyn Bell)
 & Aperture synthesis (1967)
– Martin Ryle
 Verification of Einstein's prediction of gravitational radiation
– 1993 Noble prize to Taylor and Hulse
Discoveries made with new
instruments: CMB discovery
 Unexpected discovery
 Used a telescope built for other purposes
– Communications
 Directly relevant to existing models of a big
bang expanding Universe
– Dicke, Novikov, Gamov
– These models had not been accepted by the
(steady state) establishment
10 Jan 2010
R D Ekers
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Radio Telescope Sensitivity
5
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Exponential increase
Jansky 1931 - the beginning
Reber
Log Relative Sensitivity
4
3
in sensitivity x 105
since 1940 !
Dwingeloo
Jodrell Bank
Parkes
2
» 3 year doubling time for
sensitivity
Bonn
1
WSRT
Arecibo
0
AT
VLA
GMRT
1hT
GBT
-1
-2
SKA
-3
1940
1950
29 Sep 2008
1960
1970
1980
Date
1990
2000
2010
R D Ekers
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Radio Telescope Sensitivity
5
 Exponential increase in
Reber
Log Relative Sensitivity
4
3
sensitivity x 105 since
1940 !
Dwingeloo
Jodrell Bank
Parkes
2

Bonn
1
WSRT
Arecibo
0
AT
VLA
GMRT
1hT
GBT
-1
» Eg Arecibo upgrade
» Parkes upgrade
» Exponential growth needs
-2
SKA
-3
1940
Upgrades can’t sustain
an exponential increase
1950
29 Sep 2008
1960
1970
1980
Date
1990
2000
new technology
2010
R D Ekers
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Commercial Drivers for
Technology
 The advances described by Moore’s Law are directly
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applicable to radio telescope design
MMIC (large scale integrated circuit) technology allows
cheap duplication of complex circuits
– Driven by eg mobile radio communications technology
 Optical fibre communications
 Cheap mass storage
 The R&D needed at radio wavelengths is directly relevant
to the broader S&T research priorities in most countries
RDE OECD Munich 2004
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New Parameter Space
 Wide FOV
– Feed arrays
 Sensitivity
– Collecting area
 Wide bandwidth
– Signal processing
 Very high angular resolution
– Wide band communications links
 Interference mitigation
29 Sep 2008
R D Ekers
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ALMA
 ALMA
– Transformational
science at mm
wavelengths
 Born in late 1980’s
– 20 year realisation
 Technology shift
from single dish to
an array
10 Jan 2009
R D Ekers
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ALMA
First Fringes: 12 Nov 2009
12 Nov 2009
ESO
16
VLA 1980
E-VLA 2010
VLA
New Mexico
Time Magazine’s Opinion
Square km telescope:
the concept
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Array with a very large number of elements
Square km of collecting area
Frequency range 0.03 - 20GHz
Sensitivity 100 x VLA
Resolution 0.1” – 0.001”
Multibeam (at lower frequencies)
12 July, 1999
R. Ekers - Square Km Array
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Square Km Array
16 feb 2006
R D Ekers
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Achieving the vision International Collaboration?
 To build facilities which no single nation can afford
 Coordination
– Avoiding wasteful competition
 Broader knowledge base, cross fertilisation
 Wealth creation
 IAU Large Telescope WG
– Initiated after the SKA resolution and discussion at the den
Hague GA in 1994
 OECD Global Science Forum
10 Jan 2010
24
o
15 Mpc at z = 2
SKA’s 1 field-of-view
29 Sep 2008
SKA 20 cm
and x100
possible!
SKA 6cm
HST
ALMA
R D Ekers
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SKA Key Science Drivers
ORIGINS
 Probing the Dark Ages
When & how were the first stars formed?
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Cosmology and Galaxy Evolution
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Atrobiology
Galaxies, Dark Energy and Dark Matter
What are the conditions for life and where can it be
found?
FUNDAMENTAL FORCES
 Strong-field tests of General Relativity
Was Einstein correct?
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Origin & Evolution of Cosmic Magnetism
Where does magnetism come from?
plus The Exploration of the Unknown
(Special Session 5)
Science with the Square
Kilometre Array
(2004, eds. C. Carilli &
S. Rawlings, New
Astron. Rev., 48)
Possible telescope configurations
Communications links + power
Dense aperture arrays
Receptors in stations
along spiral arms
Central
Processing
Facility
40 stations
5-200 km
40 remote stations
200 to >3000 km
Station
1500 dishes (15m diameter) in central ~5 km
1500 dishes from 5 km to 3000+ km
Sparse aperture arrays
Multi-pixels at mid-frequencies with a
dense aperture array
EMBRACE
SKADS
2-PAD
LOFAR IN A NUTSHELL – 1
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Frequency range
 10 - 80 MHz & 110 - 240 MHz
 Two orders of mag. improvement in
resolution and sensitivity
•
Baselines:
 ~ 100 km (NL) Initially – “Phase 1”
 ~ 1000 km (EU) Ultimately – “Phase 2”

2 km core (40% of area) + 45 stations
•
Novel Aspects:
– Most versatile of planned LF arrays
– Element/ stations with phased arrays
• ~ 17000 dipoles
• Electronic pointing
• Many simultaneous beams
– Supercomputer as correlator
– RFI mitigation
– Prototype for SKA technology
– Multidisciplinary sensor array
• e.g. Geophones and infrasound
– How does gas extraction effect earth crust?
Southern Africa
Dish construction building
First KAT7 antenna
Support base
Proposed SKA Timeline
2006 2007 2008 2009
Demonstrator
developments
Site bid
2011
SKA Pathfinder
construction
Technology selection
2020
2013
SKA Construction
2070+
Full SKA operational
Site ranking
SKA production
readiness review
Nov 2009
R. Schilizzi
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ASKAP
A few Key Science
Experiments
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Pulsars as
Gravitational Wave Detectors
Millisecond pulsars act as
arms of huge detector:
Pulsars LISA Advanced
LIGO
SKA
Pulsar Timing Array:
Look for global spatial
pattern in timing residuals! • Complementary in Frequency!
2004
Kramer - Leiden retreat (updated)
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Enhanced SETI Searching
SKA
ATA
Phoenix
Giordano Bruno
(1548-1600)
the universe is infinite,
composed of many worlds
and animated by common
life
Epoch of reionization
Avery Meiksen
29 Sep 2008
R D Ekers
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High Redshift HI Experiments
 Bebbington (1985); Uson; et alia
 Current generation:
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PAST 21CMA (Pen, Peterson, Wang: China) $$
LOFAR (de Bruyn et alia: The Netherlands) $$$
MWA (Lonsdale, Hewitt et alia: WA) $$
PAPER (Backer, Bradley: NRAO GBWA?) $$
CORE (Ekers, Subramanian, Chippendale: WA) $
 Next generation:
– SKA (International) $$$$$
5 Aug 2005
Don Backer
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CMB acoustic peaks
29 Sep 2008
R D Ekers
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Simulation of
Evolution of Acoustic Oscillations
TIME
29 Sep 2008
R D Ekers
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The excitement of these powerful new instruments is
not in the old questions they will answer
.
but in the new questions they will raise.
Nov 2009
K. I. Kellermann
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