Three Radio Astronomy Futures:

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• Three Radio Astronomy Futures
• ALMA, EVLA, SKA

Mark T. Adams Assistant Director, EPO National
Radio Astronomy Observatory http//www.nrao.edu
Osher Lifelong Learning Institute University of
Virginia 18 September 2008
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Electromagnetic Spectrum
The Domain of Radio Astronomy Wavelength 15
meters to 0.3 millimeter Frequency 20 MHz
to 1.0 THz 1 THz 1,000 GHz 1,000,000 MHz
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Green Bank Telescope

• Dedicated in 2000 in Green Bank, WV
• Located in National Radio Quiet Zone
• 100 x 110m dish 2 acres of collecting area
• Weighs 17M lbs largest moving structure on land
• Studies pulsars, complex molecules, neutral
  hydrogen

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Very Large Array

• Built in 197s, Dedicated in1980
• 27 antennas in a reconfigurable array

Studies Black holes, proto-planetary disks around
young stars, Galactic Center, cosmology
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Very Long Baseline Array

• Operated from Socorro, NM
• Ten antennas
• Hawaii to the Caribbean
• Highest resolution astronomical telescope
• Dedicated 1993

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NRAO Technology Center

• Radio Astronomy technology signal processing
  push state-of-the-art
• NTC scientists, engineers, Technicians perform
  the required Research Development

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The Invisible UniverseWhy Do Radio Astronomy?

• Radio complements other wavelengths

H o r s e h e a d N e b u l a
Optical Infrared Radio
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The Invisible UniverseHydrogen
Optical image of M81 Group (DSS)
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The Invisible UniverseCenter of our Galaxy
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Expanded Very Large Array
http//www.aoc.nrao.edu/evla
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Expanded Very Large Array

• Leverages the VLA to Enable the Next-Generation
  cm-wavelength Telescope
• builds on existing infrastructure 27 antennas,
  Track, facilities, people
• An International Collaboration United States,
  Canada, and Mexico
• Implements state-of-the-art technology
• Correlator
• wideband receivers 1 - 50 GHz
• fiber-optic data transmission system
• digital electronics
• Software

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EVLA Science Themes
Magnetic Universe
Measure the strength and structure of the cosmic
magnetic field
Obscured Universe
Sgr A
Image young stars massive black holes in dust
enshrouded environments
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EVLA Correlator

• WIDAR Wideband Interferometric Digital
  Architecture
• WIDAR is an Innovative method for digital
  correlation of very wideband signals from a radio
  interferometer
• 40 x 1015 Ops / sec

invented by Brent Carlson Peter Dewdney at
Dominion Radio Astrophysical Observatory
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Atacama Large Millimeter/submillimeter Array
http//www.alma.nrao.edu http//www.alma.cl
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ALMA Science Schedule

• Key Science
• Cosmic Origins Planets, Stars, Galaxies
• The Cold Universe
• Timeline
• 1995 site testing in Chile Begins
• 1998 Design Development Start
• 2007 First ALMA Antennas Arrive in Chile
• 2010 First Science
• 2013 ALMA Fully Operational

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ALMA Location

• mm / sub-mm radiation is blocked by water in the
  atmosphere
• MM / sub-mm telescopes must be located at very
  dry, high altitude sites
• Chajnantor plain in northern chile (Atacama
  Desert ) is the best

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Altiplano de ChajnantorRegion II, Chile
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ALMA Antennas in Chile
3 Melco Antennas
VertexRSI
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ALMA Transporter
Concept
Reality Sep 07
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Square Kilometre Array

• 1994 Community begins to Consider A Next-Gen
  Radio Telescope With A Square Kilometre (250
  Acres) of Collecting Area
• Scientific Objectives
• Technology
• Cost

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Square Kilometre Array

• Key Science Projects
• Cradle of Life
• Gravity Tests Using Pulsars Black Holes
• Origin Evolution of Cosmic Magnetism
• Galaxy Evolution Cosmology
• Probing the Dark Ages

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Square Kilometre Arraynew technology
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Square Kilometre Array

• Pathfinder Technology development projects
  underway in United States, Europe, South Africa,
  Australia
• Likely To Be 3 Separate SKA Telescope Systems
• SKA-Hi, SKA-Mid, SKA-Low
• Construction Cost 1- 2B USD for Each
• EVLA COMPLETE in 2012 SKA PATHFINDER
• SKA Fully Realized Operational 2025
• http//www.skatelescope.org

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Radio Astronomy discoveries Cosmic Microwave
Background Quasars Pulsars Gravitational
Lenses Dark Matter Masers Gravitational
Waves First Extra-solar PlanetsStay Tuned for
the EVLA, ALMA, SKA the Scientific frontiers
they will open