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NRAO VLA Home Page: What Is the VLA? What Is the VLA?

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NRAO VLA Home Page: What Is the VLA? What Is the VLA? NRAO VLA Home Page: What is the VLA? What is the VLA? The Very Large Array (VLA) is one of the world's premier astronomical radio observatories. The VLA consists of 27 antennas arranged in a huge Y pattern up to 36km (22 miles) across -- roughly one and a half times the size of Washington, DC. Each antenna is 25 meters (81 feet) in diameter; they are combined electronically to give the resolution of an antenna 36km (22 miles) across, with the sensitivity of a dish 130 meters (422 feet) in diameter. More photographs of the VLA History: ❍ 1972 August: approved by Congress ❍ 1973 April: construction started ❍ 1975 September 22: first antenna put in place ❍ 1976 February 18: first fringes ❍ 1981 January: entire array completed nearly one year ahead of schedule! The total cost was $78,578,000 (in 1972 dollars), roughly $1 per tax-payer at the time; the project was completed within the allotted budget. Location: Plains of San Agustin, west of Socorro, New Mexico. ❍ latitude = 34 04' 43.497" north ❍ longitude = 107 37' 03.819" west ❍ elevation = 2124 m http://www.nrao.edu/doc/vla/html/VLAintro.shtml (1 of 3) [5/26/1999 1:22:34 PM] NRAO VLA Home Page: What is the VLA? Size: Each antenna: 25m in diameter, 230 tons. The array: There are four configurations: A array, with a maximum antenna separation of 36km; B array -- 10km; C array -- 3.6km; and D array -- 1km. The telescopes are switched between these configurations every four months or so. Resolution: 0.04arcseconds The resolution of the VLA is set by the size of the array -- up to 36km (22 miles) across. At our highest frequency (43GHz) this gives a resolution of 0.04 arcseconds: sufficient to see a golf ball held by a friend 150km (100 miles) away. Of course, very few golf balls contain high-power radio transmitters... Misc. antenna information: Slew rates: 40 degrees per minute in azimuth, 20 degrees per minute in elevation Minimum elevation angle: 8 degrees above the horizon Frequency coverage: The VLA can observe at various bands between 300 and 50,000 MHz (90 to 0.7cm): Receivers Available at the VLA C X P Band L Band U Band K Band Q Band Band Band Frequency 0.30-0.34 1.34-1.73 4.5-5.0 8.0-8.8 14.4-15.4 22-24 40-50 (GHz) Wavelength 90 20 6 3.6 2 1.3 0.7 (cm) Primary beam 150 30 9 5.4 3 2 1 (arcmin) Highest resolution 6.0 1.4 0.4 0.24 0.14 0.08 0.05 (arcsec) System 150-180.K 37-75.K 44.K 34.K 110.K 160-190.K 90-140.K Temp http://www.nrao.edu/doc/vla/html/VLAintro.shtml (2 of 3) [5/26/1999 1:22:34 PM] NRAO VLA Home Page: What is the VLA? How does it work? The VLA is an interferometer; this means that it operates by multiplying the data from each pair of telescopes together to form interference patterns. The structure of those interference patterns, and how they change with time as the earth rotates, reflect the structure of radio sources on the sky: we can take these patterns and use a mathematical technique called the Fourier transform to make maps. Who uses it? The VLA is used primarily by astronomers from around the world. It's also occasionally used for atmospheric/weather studies, satellite tracking, and other miscellaneous science. If you would like to use the VLA for your research experiment, please see the instructions for submitting proposals . Who runs it? The VLA is operated by the National Radio Astronomy Observatory (NRAO), which is a facility of the National Science Foundation (NSF), operated under cooperative agreement by Associated Universities, Inc. (AUI). Can I go see it? The VLA is open to the public; follow this link for directions and other information. Pretty images from the VLA Images from the local website Alan Bridle's beautiful jets Recent results Recent press releases Highlights of this month's VLA observations VLA Home Page Last modified 20 April 1999 [email protected] http://www.nrao.edu/doc/vla/html/VLAintro.shtml (3 of 3) [5/26/1999 1:22:34 PM] Some Aerial Views of the VLA Some Aerial Views of the VLA Click on any image for a larger version. All photos are by Dave Finley, courtesy National Radio Astronomy Observatory and Associated Universities, Inc. An overall view of the VLA in its closest configuration, looking North-Northeast. Overall view of the VLA, looking South. http://www.nrao.edu/intro/vlapix/vlaviews.index.html (1 of 4) [5/26/1999 1:24:59 PM] Some Aerial Views of the VLA The North Arm of the VLA, looking South toward the center. The center of the VLA, with the antennas in close configuration. http://www.nrao.edu/intro/vlapix/vlaviews.index.html (2 of 4) [5/26/1999 1:24:59 PM] Some Aerial Views of the VLA A close-in look at the center of the VLA. The VLA, with Tres Montosas in the background. http://www.nrao.edu/intro/vlapix/vlaviews.index.html (3 of 4) [5/26/1999 1:24:59 PM] Some Aerial Views of the VLA Twilight on the VLA, looking Southwest. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.. http://www.nrao.edu/intro/vlapix/vlaviews.index.html (4 of 4) [5/26/1999 1:24:59 PM] NRAO Very Large Array Images Images from the Very Large Array ● The Extra-galactic Radio Source Cygnus A ( 235k): ● The Supernova Remnant Cas A ( 369k): http://www.nrao.edu/doc/vla/html/VLA-images.shtml (1 of 2) [5/26/1999 1:25:33 PM] NRAO Very Large Array Images ● The Arc at the Galactic Center ( 235k): Last modified 28 November 1995 [email protected] http://www.nrao.edu/doc/vla/html/VLA-images.shtml (2 of 2) [5/26/1999 1:25:33 PM] Alan Bridle's Image Gallery Images of Radio Galaxies and Quasars Images on this page are thumbnails, linked to larger (30-80k) versions Radio Galaxies | 3C31 | 3C219 | 3C272.1 | 3C288 | 3C353 | Quasars | Index & description | | 3C175 | 3C204 | 3C215 | 3C263 | 3C334 | 3C351 | Images at Other WWW Sites Go back to: ● Alan Bridle's Home Page ● NRAO Charlottesville Home Page ● NRAO VLA Home Page ● AstroWeb Home Page HTML 3.2 last updated: 1998 August 25, 14:46 EDT http://www.cv.nrao.edu/~abridle/images.htm [5/26/1999 1:26:05 PM] NRAO Recent Press Releases National Radio Astronomy Observatory Recent Press Releases 1999: ● Superfast Cosmic Jet "Hits the Wall" ● Astronomers Discover Rotating Disk Around Young, Massive Star ● "Movie Star" Acting Strangely, Astronomers Find ● Astronomers Discover Spectacular Structure in Distant Galaxy 1998: ● Nearby Quasars Result From Galactic Encounters, VLA Studies Indicate ● New Mexico Fiber-Optic Link Marks Giant Leap Toward Future of Radio Astronomy ● Astronomers Surprised to Find Elongated Radio-Emitting Region at Center of Milky Way ● Possible Analog for Early Solar System Disk Found ● Cosmic Flasher Reveals All ● Background Information: Magnetars, Soft Gamma-Ray Repeaters and the Most Powerful Magnetic Fields in the Universe ● VLA Reveals Surprising Pair of Potential Planetary Systems ● VLA Observations Confirm Origin of Gamma Ray Bursts in Short-Lived Stars ● Background Information: Deciphering Gamma Ray Burst Physics With Radio Telescopes ● Strange, Bursting Star System Has Astronomers Scrambling ● VLA Shows "Boiling" in Atmosphere of Betelgeuse 1997: ● Radio Observations Provide New Clues to Gamma Ray Fireball ● Astronomers Make First Images With Space Radio Telescope http://www.aoc.nrao.edu/doc/pr/pr.html (1 of 3) [5/26/1999 1:26:20 PM] NRAO Recent Press Releases ● Radio Astronomers Reveal "Bizarre" Behavior of Gamma Ray Burster ● Curved Radio Jet in Center of Nearby Galaxy Complicates Picture of Active Galactic Nuclei ● VLBA Gives Researchers Unprecedented Look at Workings of Distant Star ● Very Large Array Detects Radio Emission from Gamma-Ray Burst ● "Axis of Universe" Not Seen in Data, Astronomers Say ● Launch Will Create a Radio Telescope Larger than Earth ● New Observations Deepen Mystery Surrounding Water Masers in Elliptical Galaxy ● "Microquasar" Discoveries Win Prize for Astronomers ● Extraordinary Cosmic Laboratory Helps Unravel Mysteries of a Galaxy's Powerful Central "Engine" 1996: ● New Technologies Promise Dramatic Increase In Capabilities of the Very Large Array ● NRAO 12-Meter Radio Telescope Detects Molecular Emission from Comet Hyakutake ● Middle-School Students to Make Optical Observations During VLA Radar Study of Comet Hyakutake ● Research Teams Will Use Very Large Array To Study Close-Passing Comet ● Detecting Extrasolar Planets With Millimeter-Wave Observatories ● New Galaxies From Old? VLA Observations Strengthen the Case 1995: ● Astronomers Make "Movie" of Radio Images Showing Supernova Explosion ● VLA Will Receive Galileo Probe Signals To Measure Jupiter's Winds ● Emerging Picture of Black Hole in Double-Star System Promises Exciting Yield of New Physics Data ● VLBA Tracks Ejected Material From Mysterious X-Ray Nova ● Tremendous Mass Concentration in Strange Galaxy Revealed by VLBA 1994: ● Superluminal Motion Found In Milky Way ● NRAO Makes Available VLA Sky Survey Maps For additional information, please contact Dave Finley http://www.aoc.nrao.edu/doc/pr/pr.html (2 of 3) [5/26/1999 1:26:20 PM] NRAO Recent Press Releases [email protected] http://www.aoc.nrao.edu/doc/pr/pr.html (3 of 3) [5/26/1999 1:26:20 PM] NRAO Very Large Array Home Page NRAO Very Large Array What is the VLA? What's New at the VLA? ● Important notices and announcements ● Current and upcoming configurations ● Proposal deadlines ● Current schedule, newsletter, test minutes, memos, and software ● Press releases The VLA Expansion Project Contact People Using the VLA ● Asking for time ● Preparing for observations ● Phase Monitor ● Visiting the VLA ● After the observations ● Publications Documentation
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