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Low Hanging Fruit in The New Radio Sky or Radio Surveys and Transients with the Allen Telescope Array or The Same Road Twice. Geoffrey Bower, UC Berkeley. ATA-42 Operational Soon. ATA FiGSS F ive G Hz S ky S urvey. 5 GHz Counterpart to Sloan Digital Sky Survey
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Low Hanging Fruit inThe New Radio SkyorRadio Surveys and Transients with the Allen Telescope ArrayorThe Same Road Twice Geoffrey Bower, UC Berkeley
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 • 6 calendar months to complete with ATA-42 • Extendable in area and sensitivity
FiGSS Science • Detect 250,000 Sources • Cross with NVSS: 1.4-5 GHz Spectral Indices • Separate star burst galaxies from AGN • Arp 220 detectable to z=0.16 (0.3, 0.5) • Cross with SDSS, SWIRE, COSMOS • Galaxy evolution • Obscured star-formation and AGN science • AGN activity census • Radio continuum-star formation relations • Polarization & Rotation Measure (103 --106 rad m-2) for all objects • Identify hidden or depolarized nonthermal sources: jets, SNe remnants • Dense probe of ISM B-field • Galactic foregrounds for CMB and EOR • Community property • Virtual Observatory catalog • Survey sample lists • NVSS+FIRST produced more than 1000 refereed citations • Gravitational lens source list • Flat spectrum, compact objects • Geometry of the Universe (ala CLASS project) • Transient detection
FiGSS Layer Cake Transients & Steady Sources 10 Sq. Deg. 0.3 mJy Daily Overlap COSMOS 100 Sq. Deg. 1 mJy Every 10 Days Overlap with SWIRE 10,000 Sq. Deg. 3 mJy Every 100 Days Overlap with SDSS/FIRST/NVSS
Radio Transient Source Counts FiGGS Orphan Afterglows RSNe Tidal Flares IDV ???
Transients Discovered in the VLA Archives • VLA calibration check observations • 1983-2003 • ~1000 weekly epochs • 1.4, 5, 8.4 GHz • 40 uJy rms/epoch • Effective surveyed area at 600 microJy ~10 sq degrees 10 Transients Discovered (□◊Δ) Very Deep, Multi-λ Images: 2.6 uJy rms
The Same Road Twice:Conclusions for Legacy Science • The radio astronomy landscape is changing • ATA is coming soon (also LOFAR, LWA, etc.) • Complementarity & synergy of efforts is critical • ATA has powerful survey capability • Commensal RA & SETI • FiGSS: simultaneous survey for transient and stationary sources • Archival data are a powerful legacy product