B.J.Boyle

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Science with the SKA

• B.J.Boyle
• On behalf of the
• International SKA community

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Definition

• SKA es-kay-ay (n.) a radio telescope designed
  to address fundamental contemporary questions
  regarding the physical nature of our Universe and
  the laws underpinning it.

Fundamental science will also be done with 1
pathfinders and 10 SKA Phase 1
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Connecting Quarks with the Cosmos Eleven
Science Questions for the New CenturyUS National
Academies Board on Physics Astronomy (2003)
What Is the nature of the Dark Energy? How did
the Universe begin? Did Einstein have the last
word on gravity? What are the masses of the
neutrinos and how have they shaped the evolution
of the Universe? What is Dark Matter? How do
cosmic accelerators work and what are they
accelerating?
Are protons unstable? What are the new states of
matter at exceedingly high density and
temperature? Are there additional space-time
dimensions? How were the elements from iron to
uranium made? Is a new theory of matter and light
needed at the highest energies?
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A rich history of discovery

• Many discoveries over the past 50yr
• Pulsars
• Microwave Background
• Cosmic Evolution
• Dark Matter in galaxies
• Quasars
• Jets Superluminal motion
• Gravitational Radiation
• Aperture Synthesis

The Discovery of Pulsars
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Radio provides unique information about the
Universe
Mobile Phone
Aircraft
Digital TV
Neutral Hydrogen
FM
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Radio provides unique information about the
Universe

• Non-thermal processes quasars, pulsars, jets

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Radio provides unique information about the
Universe
Tracer for Cosmic Magnetic Fields
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Radio provides unique information about the
Universe
Penetrates dust and gas
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Square Kilometre Array

• Current radio telescopes based on pre-1980s
  technology
• Science now demands
• 1. Large increase in sensitivity ? 1km2 (50 x)
• Observe neutral hydrogen throughout the universe
• 2. Large increase in field-of-view ? 50deg2
  (200x)
• Survey entire sky
• 3. High spatial resolution ? 1mas (Already
  achieved)
• Resolve protoplanetary disks

Discovery Potential Area X f.o.v. 10000 x
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SKA Key Science Drivers

• Probing the Dark Ages
• When how were the first stars formed?

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SKA Key Science Drivers

• Probing the Dark Ages
• When how were the first stars formed?
• Cosmology and Galaxy Evolution
• Nature of Dark Energy and Dark Matter

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SKA Key Science Drivers

• Probing the Dark Ages
• When how were the first stars formed?
• Cosmology and Galaxy Evolution
• Nature of Dark Energy and Dark Matter
• Strong-field tests of General Relativity
• Was Einstein correct?

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SKA Key Science Drivers

• Probing the Dark Ages
• When how were the first stars formed?
• Cosmology and Galaxy Evolution
• Nature of Dark Energy and Dark Matter
• Strong-field tests of General Relativity
• Was Einstein correct?
• Origin Evolution of Cosmic Magnetism
• Where does magnetism come from?

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SKA Key Science Drivers

• Probing the Dark Ages
• When how were the first stars formed?
• Cosmology and Galaxy Evolution
• Nature of Dark Energy and Dark Matter
• Strong-field tests of General Relativity
• Was Einstein correct?
• Origin Evolution of Cosmic Magnetism
• Where does magnetism come from?
• Cradle of Life
• What and where are the conditions for life?

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Probing the Dark Ages
COSMIC HISTORY OF THE UNIVERSE
The Dark Ages Era of the Universe from 300 000 -
1 000 000 000 yr after the Big Bang during which
the first stars and galaxies formed
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Probing the Dark Ages
SKA Role Detect and image hydrogen in the dark
ages - shed light on the physics of the formation
of the first objects in the Universe
COSMIC HISTORY OF THE UNIVERSE
18.3
16.1
14.5
13.2
12.1
11.2
10.4
9.8
9.2
8.7
8.3
7.9
7.5
7.2
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The Nature of Dark Energy
Route to Dark Energy Cosmic Ripples
established at time of Microwave Background
provide characteristic length scales in
distribution of galaxies on the sky
The Composition of the Universe
(3.5 HYDROGEN)
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The Nature of Dark Energy
Route to Dark Energy Super-accurate measurements
of this length scale at various look back times
can discriminate between models for dark energy
The Composition of the Universe
(3.5 HYDROGEN)
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The Nature of Dark Energy
SKA Role Locate and measure spatial distribution
of 109 galaxies via their hydrogen emission
The Composition of the Universe
(3.5 HYDROGEN)
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The Nature of Dark Energy
Sloan Digital Sky Survey
500 000 galaxies
Low accuracy 30 limits of Dark Energy
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The Nature of Dark Energy
1 000 000 000 galaxies
SKA
SKA will provide highest accuracy measurement of
Dark Energy proposed
First complete history of dominant baryonic
component of the Universe
30 000 Million Light Years
was ??
High accuracy 1 limits on dark energy
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Was Einstein Right?
Pulsars Collapsed stars with extreme physical
properties
Most accurate clocks known 10-9sec
High Gravity Field 200000xSun
Pulsars Cosmic Lighthouses
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Was Einstein Right?
SKA role Identify and time pulsars with
nano-second accuracy
SKA will find 20 000 pulsars in our Galaxy
Clocks
Gravity
Sensitive gravity wave detector
Test GR around Black Holes
Surpass all proposed tests
Complementary to Adv. LIGO/LISA
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The Origin of Cosmic Magnetism

• Four fundamental forces in Nature
• strong, weak forces role in astrophysics well
  understood
• gravity complete theory
• lots of future observations to test this
• (electro-)magnetism complete theory
• permeates time space
• role origin largely unknown

Magnetic Fields shape cosmic structures
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The Origin of Cosmic Magnetism
Magnetic Fields role in star formation?

• Magnetic fields are crucial in
• galaxy star formation
• turbulence gas motions
• acceleration propagation of cosmic rays
• Fundamental unsolved problem
• Top-down or bottom-up process
• Exotic origin (phase transitions, strings)?
• standard plasma physics (turbulence,
  instabilities)

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The Origin of Cosmic Magnetism

• Radio observations provide a unique probe of
  cosmic magnetic field
• Synchrotron emission, Polarization
• SKA will provide first detailed 3D picture of
  cosmic magnetic field
• Polarization studies of 100 000 000 sources
• 10000 x improvement

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The Cradle of Life

• Test conditions for life elsewhere in the
  Universe
• Image proto-planetary disks
• Search for Extraterrestial intelligence

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The Cradle of Life
SKA Role Movies of proto-planetary disks in
formation
milliarcsec resolution
cm??
Theoretical Simulation
Probe the Habitable zone in disks
Composition of building blocks of disks
Complementary to (and surpasses) ALMA/ELT
Complements ALMA
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The Cradle of Life
The Search for Extraterrestial Intelligence Airpo
rt radars _at_ 100 l.y. 500 stars Ionospheric radar
_at_5000 l.y. 600 000 000 stars
SKA 1000-fold improvement
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Connecting Quarks with the Cosmos Eleven
Science Questions for the New CenturyUS National
Academies Board on Physics Astronomy (2003)
What Is the nature of the Dark Energy? How did
the Universe begin? Did Einstein have the last
word on gravity? What are the masses of the
neutrinos and how have they shaped the evolution
of the Universe? What is Dark Matter? How do
cosmic accelerators work and what are they
accelerating?
Are protons unstable? What are the new states of
matter at exceedingly high density and
temperature? Are there additional space-time
dimensions? How were the elements from iron to
uranium made? Is a new theory of matter and light
needed at the highest energies?
?
?
?
?
?
?
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Exploration of the Unknown

• Unplanned discoveries
• Pulsars
• Microwave Background
• Cosmic Evolution
• Dark Matter in galaxies
• Quasars
• Jets Superluminal motion

SKA Discovery Potential 10000 x existing radio
telescopes
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Exploration of the Unknown

• Design Strategies
• Flexibility
• Area, Field-of-view
• Time resolution buffering
• Frequency coverage
• Upgradability
• Multiple simultaneous use

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Telescope Productivity
Roy, Puxley and Crabtree 2005
Major Ground-Based Facilities
Radio Telescope VLA
Number of papers
Optical Telescopes
Age of Telescope (yrs)
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SKA science book
Science with the Square Kilometre Array,
eds C.Carilli, S.Rawlings, New Astronomy
Reviews, Vol.48, Elsevier, Dec. 2004
www.skatelescope.org