Future Radio Synoptic Surveys

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Future Radio Synoptic Surveys

• Geoffrey C Bower
• (UC Berkeley)

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Square Kilometer ArrayThe Global Radio
Wavelength Observatory

• Originally Hydrogen telescope
• Detect H I emission from Milky Way-like galaxy at
  z 1
• SKA science much broader
• Multi-wavelength, multi-messenger
• On-going technical development
• International involvement

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SKA Key Science

• International working group
• Strong-field Tests of Gravity with Pulsars and
  Black Holes
• Galaxy Evolution, Cosmology, Dark Energy (see
  Henning talk)
• Emerging from the Dark Ages (see Backer talk)
• The Cradle of Life/Astrobiology
• The Origin and Evolution of Cosmic Magnetism
• Exploration of the Unknown

Science with the Square Kilometre Array (2004,
eds. C. Carilli S. Rawlings, New Astron. Rev.,
48)
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A New Era for Radio Astronomy
Karoo Array Telescope (meerKAT, ZA)
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A New Era for Radio Astronomy

• Meter-wavelength instruments
• Epoch of Reionization, Transients, Ionospheric
  Science
• Sparse arrays
• All Sky Monitors

Karoo Array Telescope (meerKAT, ZA)
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A New Era for Radio Astronomy
Karoo Array Telescope (meerKAT, ZA)

• Large-NumberSmall-Diameter Arrays
• Galaxy Assembly Evolution, Gravitational
  Physics, Dynamic Radio Sky,

• Novel antenna construction methods
• Wide-band feeds

• Field of view expansion
• Signal transmission
• Processing and data management

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A New Era for Radio Astronomy

• Existing facilities
• Epoch of Reionization, Galaxy Assembly
  Evolution, Gravitational physics, Dynamic Radio
  Sky,
• Wide band feeds
• Field of view expansion
• Signal transmission
• Processing and data management

Karoo Array Telescope (meerKAT, ZA)
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Next Generation Radio Telescopes

• Design Principles

• Characteristics

• Trade steel for silicon
• ?LNSD
• Digital hardware is an operating cost
• Upgrade backend processors frequently following
  Moores Law
• Commensal observing
• Do multiple projects simultaneously in different
  instruments

• Wide field of view
• Flexible signal processing
• Broad frequency coverage

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Commensal Survey Science
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Transient Science is Exploding
New Phenomena
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MM Wavelength T Tauri Outburst in Orion Nebula
Star GMR-A
BIMA A configuration images
D389 pc /- 5 lt0.1 mas/epoch
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Unknown Radio Transientsfrom VLA Archival Survey
VLA 5 GHz
Keck G,R
Bower et al 2007
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Characterization of the Time Domain

• Transient Event Rates

• Wide Open Parameter Space

ATA 24 Hours
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The Allen Telescope Array

• 42 x 6.1m dishes
• Expansion goal of 350
• Very wide FOV
• Flexible Signal Processing
• Project of UC Berkeley RAL SETI Institute
• Funded through private/public partnership
• Key Science Surveys
• Transients
• Extragalactic Hydrogen
• Galactic Spectroscopy
• Pulsar Timing
• SETI

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ATA is a Powerful Survey Telescope

• LNSD gives very high survey speed i.e., wide
  field of view
• Flexible digital electronics enables exploration
  of broad range of timescales and angular scales
• Commensal observing

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ATA FiGSS Five GHz Sky Survey

• 5 GHz Counterpart to Sloan Digital Sky Survey
• Overlap with NVSS, FIRST SDSS
• 104 Square degrees
• Arcminute resolution
• Highest Frequency Deep, Large Radio Survey
• 0.6 mJy rms
• Factor of 10 more sensitive than GB6
• 2 Smaller, deeper fields
• 10 sq deg repeated every day
• 100 sq deg repeated every 10 days
• 6 calendar months to complete with ATA-42
• Extendable in area and sensitivity

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FiGSS Science

• Detect 250,000 Sources
• Virtual Observatory catalog
• Survey sample lists
• NVSSFIRST produced more than 1000 refereed
  citations
• Cross with NVSS 1.4-5 GHz Spectral Indices
• Separate star burst galaxies from AGN
• Arp 220 detectable to z0.16 (0.3, 0.5)
• Cross with SDSS, SWIRE, COSMOS
• Galaxy evolution
• Obscured star-formation and AGN
• AGN activity census
• Radio continuum-star formation relations
• Highest redshift AGN
• Polarization Rotation Measure for all objects
• Dense probe of ISM B-field
• Galactic foregrounds for CMB and EOR
• Gravitational lens source list
• ? Geometry of the Universe (ala CLASS project)
• Transient detection

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Radio Transient Source Counts
FiGGS
10 deg2
100 deg2


10000 deg2
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FiGSS Known Unknowns

• Exploration of the nonthermal Universe is
  uniquely radio domain
• High Energy Astrophysics
• Black holes, neutron stars, magnetic fields,
  accretion and outflows
• Tidal Disruption of Stars by SMBHs
• Orphan Gamma-ray Burst Afterglows
• Radio Supernova Rate
• Flare Star Statistics
• The Unknown
• Follow-up is key for classification
• Approved Gemini Swift programs for optical
  X-ray follow-up
• Will implement VOEvent for rapid notification

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ATATS ATA 20 CM Survey
Precursor to FiGSS 800 square degrees 350
pointings In 10 hours gt10 epochs
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ATA Flys Eye Experiment
Flys Eye Team Bower, Werthimer, van Leeuwen,
Cordes (Cornell) ATA Team Andrew Siemion,
Peter McMahon, Jason Manley, Griffin Foster,
Mark Wagner
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Early Results

• Concept --- October 07
• Technical solution identified --- Nov 07
• Hardware installation on 2122 December 2007
• 1600 Hz readout
• 208 MHz bandwidth
• 128 spectral channels
• 44 signal paths
• S_rms 15 Jy
• Omega_ATA 400 Omega_PMB

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Flys Eye Campaign

• 600 hours of observing
• February, March and April 2008
• 13 TB of data
• 50,000 CPU-hour to process

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Other Transient Searches

• The Whole Sky, Everyday
• Targeted searches (1 msec to 1 year) of
• Galactic Center
• Andromeda Galaxy
• Virgo Cluster
• Simultaneous searches with other wide field of
  view telescopes

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Radio Transient Network

• Follow-up Telescopes

• Radio Survey Telescopes

Optical/High Energy Survey Telescopes
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Did Einstein Have the Last Word on Gravity?
Fundamental Physics Dark Energy GR BHs Strong
Force

• Gmn Lgmn 8pGTmn/c4
• Relativistic binaries probe
• Equivalence principle
• Strong-field tests of gravity
• Only neutron star-neutron star binaries known
• Black hole-neutron star binaries?

PSR J0737?3039
Kramer et al.
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SKA Gravitational Wave Detector
Fundamental Physics Dark Energy GR BH Strong
Force

• Test masses on lever arm
• Pulsar Timing Array freely-falling millisecond
  pulsars
• LIGO suspended mirrors
• LISA freely-falling masses in spacecraft

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Summary

• Transient parameter space is wide open
• New discoveries indicate rich phenomena
• New telescopes, correlators, DSP, real time
  imaging will significantly extend our reach into
  time-domain parameter space