chautauqua 2007 ulvestad

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, 2007

The Very Large Array (VLA) : 

The Very Large Array (VLA)

Very Long Baseline Array (VLBA) : 

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

Robert C. Byrd Green Bank Telescope : 

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

Atacama Large Millimeter Array : 

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

Green Bank Interferometer: 

Green Bank Interferometer

Starting the VLADirt, Dirt, and More Dirt: 

Starting the VLA Dirt, Dirt, and More Dirt

The VLA Last Summer: 

The VLA Last Summer

Dedication Ceremony: 1980: 

Dedication Ceremony: 1980

The Long VLA Railroad System: 

The Long VLA Railroad System

Traffic Jam, VLA Style: 

Traffic Jam, VLA Style

VLA Synthesized Aperture: 

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

Synthesized Aperture—1 hour: 

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

Synthesized Aperture—10 hours: 

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

Radio Galaxy Cygnus A: Pre-VLA: 

Radio Galaxy Cygnus A: Pre-VLA

Cygnus A Imaged by the VLA: 

Cygnus A Imaged by the VLA

Gravitational Lenses: 

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

VLA as a Telemetry Receiver: 

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

Cataclysmic Explosions in Distant Galaxies: 

Cataclysmic Explosions in Distant Galaxies

Center of our Galaxy: 

Center of our Galaxy

Betelgeuse ( Orionis): 

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

Mercury: A Hot Planet with Ice: 

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

Doubling the Observing Frequency: 

Doubling the Observing Frequency Antenna 11 surface, before and after

The Most Distant Quasar: 

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

The Pie Town Link: 

The Pie Town Link Commercial fiber link to Pie Town VLBA antenna First VLA experience with fiber data transmission

Maintaining the Infrastructure: 

Maintaining the Infrastructure Azimuth bearings now replaced on 11 VLA antennas

More Than 2000 Antenna Moves: 

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

Observations in October 2004: 

Observations in October 2004

23 Minutes of Observing: 

23 Minutes of Observing

The Expanded VLA (EVLA): 

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 improved only incrementally from 1980 through 2005 The Expanded VLA will keep the instrument at the forefront for another 20 years Using modern electronics technology to build a “new” telescope on the infrastructure of the old VLA

EVLA Project: 

EVLA Project Increase bandwidth by factor of almost 100, and sensitivity by a factor of 10

EVLA Frequency Coverage: 

EVLA Frequency Coverage Continuous frequency coverage from 1 GHz to 50 GHz Detect CO at almost any redshift

EVLA Correlator: 

EVLA Correlator Many times more spectral coverage

EVLA New Capabilities Timescale: 

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

EVLA Primary Science: 

EVLA 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

First 28 Years of VLA Observations: 

First 28 Years of VLA Observations

VLA: The Adventure Continues : 

VLA: The Adventure Continues