Global telescope array links successfully with GBT

May 9, 2014 by Charles E. Blue

For the first time, the National Science Foundation's Green Bank Telescope (GBT) was successfully linked with a network of millimeter-wavelength telescopes, giving a powerful boost to an observatory known as the Global Millimeter VLBI Array. (VLBI stands for Very Long Baseline Interferometry, a technique that allows many widely spaced radio antennas to function as a single telescope.)

An international team of astronomers used this supercharged array to peer into the center of the giant elliptical galaxy M87, which is famous among astronomers for its prominent jet of energetic particles that stream away from its central black hole.

The 100-meter GBT is the world's largest fully steerable radio and the largest single-dish telescope capable of millimeter-wavelength observations. It joined in this international observation to help test two theories of how black holes accelerate material into jets. If the results reveal a change in shape near the base of the jets, from parabolic to conical, then it's believed that they are powered by two separate forces: the magnetic field in the accretion disk and the centrifugal force of the material in the . If the shape of the jets is more uniform, then the particles are likely accelerated by the high pressure the material experiences when it falls into the black hole.

The Global Millimeter VLBI Array normally consists of 13 stations spread across the globe from the United States (including the NRAO's Very Long Baseline Array), to six stations located in Europe. The GBT provides seven times the signal of the next biggest participating telescope. During its inaugural observation, the GBT was selected as the reference antenna because it provided the best and most stable signal. "The addition of the GBT to the GMVA will allow scientists from all around the world to study weaker objects and image material closer to in the center of galaxies," said NRAO astronomer Toney Minter.

Explore further: For the first time, astronomers have measured the radius of a black hole

More information: public.nrao.edu/telescopes/gbt

Related Stories

Massive outburst in neighbor galaxy surprises astronomers

January 7, 2013

(Phys.org)—The surprising discovery of a massive outburst in a neighboring galaxy is giving astronomers a tantalizing look at what likely is a powerful belch by a gorging black hole at the galaxy's center. The scientists ...

Hidden details revealed in nearby starburst galaxy

December 9, 2013

Using the new, high-frequency capabilities of the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT), astronomers have captured never-before-seen details of the nearby starburst galaxy M82. These new ...

Recommended for you

Ceres image: The lonely mountain

August 25, 2015

NASA's Dawn spacecraft spotted this tall, conical mountain on Ceres from a distance of 915 miles (1,470 kilometers).

Dawn spacecraft sends sharper scenes from Ceres

August 25, 2015

The closest-yet views of Ceres, delivered by NASA's Dawn spacecraft, show the small world's features in unprecedented detail, including Ceres' tall, conical mountain; crater formation features and narrow, braided fractures.

New Horizons team selects potential Kuiper Belt flyby target

August 29, 2015

NASA has selected the potential next destination for the New Horizons mission to visit after its historic July 14 flyby of the Pluto system. The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 that orbits ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.