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The VLA: Past Glories and Future Discoveries

The VLA: Past Glories and Future Discoveries. Jim Ulvestad (VLA/VLBA Director) National Radio Astronomy Observatory July 12, 2006. The Very Large Array (VLA). Very Long Baseline Array (VLBA). 1993 dedication Operated from Socorro 10 25-m antennas Highest resolution imager in astronomy

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The VLA: Past Glories and Future Discoveries

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  1. The VLA: Past Glories and Future Discoveries Jim Ulvestad (VLA/VLBA Director) National Radio Astronomy Observatory July 12, 2006

  2. The Very Large Array (VLA)

  3. Very Long Baseline Array (VLBA) • 1993 dedication • Operated from Socorro • 10 25-m antennas • Highest resolution imager in astronomy • sub-milliarcsec

  4. Robert C. Byrd Green Bank Telescope • 2000 dedication • Operated from West Virginia • 100 x 110m, novel offset design • Now operating at frequencies up to 43 GHz

  5. Atacama Large Millimeter Array • Joint project of North America and Europe (plus Japan) • Up to 64 12m antennas • Will operate up to 850 GHz (0.35 mm wavelength) • At 5000 meters (16,500 feet) elevation

  6. Green Bank Interferometer

  7. Starting the VLADirt, Dirt, and More Dirt

  8. The VLA Last Monday

  9. Dedication Ceremony: 1980

  10. The Long VLA Railroad System

  11. Traffic Jam, VLA Style

  12. VLA Synthesized Aperture • Synthesized aperture in a few minutes, as “seen” by the radio source • Composed of 351 pairs of antennas

  13. Synthesized Aperture—1 hour • Synthesized aperture after 1 hr of Earth rotation • Each pair “fills in” more of the aperture

  14. Synthesized Aperture—10 hours • Synthesized aperture after 10 hrs of Earth rotation • Aperture is “filled in” • Very high fidelity imaging

  15. Radio Galaxy Cygnus A: Pre-VLA

  16. Cygnus A Imaged by the VLA

  17. Gravitational Lenses The first Einstein ring, discovered by the VLA An intervening galaxy “lenses” a background quasar into a ring

  18. VLA as a Telemetry Receiver • New receiving system (8.4 GHz) installed for 1989 Voyager 2 Neptune encounter • Doubled the data rate possible from NASA’s Deep Space Network alone

  19. Cataclysmic Explosions in Distant Galaxies

  20. Center of our Galaxy

  21. Betelgeuse ( Orionis) Red supergiant in Orion Star contains a very bright radio-emitting corona Caused by convection and mass loss in star’s atmosphere

  22. Mercury: A Hot Planet with Ice Radar transmitted by NASA tracking station is reflected and received by VLA Red dot at top is water ice in shaded crater at North Pole

  23. Doubling the Observing Frequency • Antenna 11 surface, before and after

  24. The Most Distant Quasar Walter et al. 2003 • Optical Image • VLA image of CO from the first known star formation • Redshifted to 46 GHz • Artist’s conception of disk of molecules and dust

  25. The Pie Town Link • Commercial fiber link to Pie Town VLBA antenna • Demonstrator for EVLA Phase 2

  26. Maintaining the Infrastructure • Azimuth bearings now replaced on 11 VLA antennas

  27. More Than 2000 Antenna Moves • Reconfigure antennas 7 times every 16 months • Replace 4000 railroad ties per year

  28. Observations in October 2004

  29. 23 Minutes of Observing

  30. The Expanded VLA (EVLA) More than 700 astronomers use the VLA every year … However, most of the electronic equipment dates back to the late 1970s The VLA has produced more published science than any other telescope on the face of the Earth However, its capabilities have improved only incrementally over the last 20 years The Expanded VLA will keep the instrument at the forefront for another 20+ years

  31. EVLA Phase 1 • Increase bandwidth by factor of over 100, and sensitivity by a factor of 10

  32. EVLA Phase 1 • Continuous frequency coverage from 1 GHz to 50 GHz • Detect CO at almost any redshift

  33. EVLA Phase 1 • Many times more spectral coverage

  34. EVLA New Capabilities Timescale • The old correlator will be employed until the new correlator achieves full capability • User availability in 2010 • Full band tuning available sooner

  35. EVLA-1 Primary Science • The Magnetic Universe: From the Sun to the intergalactic medium • The Transient Universe: From stellar black holes to gamma-ray bursts • The Obscured Universe: From planetary atmospheres to active galaxies • The Evolving Universe: From nearby star formation to the earliest galaxies

  36. EVLA Phase 2 • New Mexico Array • Add 8 new 25m antennas, along with 2 VLBA antennas • Baselines up to 350 km • Resolution better than 0.01 arcsec • Proposal declined by NSF

  37. 28 Years of VLA Observations

  38. VLA: The Adventure Continues

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