Virginia Tech’s latest and largest array radio telescope project is located in the New Mexico desert. There, Virginia Tech researchers have teamed with counterparts from the University of New Mexico to operate 258 dual-polarized dipole antennas that combine to form a massive array radio telescope tasked with cracking the mysteries behind the universe’s beginning.
Heading the Long Wavelength Array (LWA1) project for Virginia Tech is Steve Ellingson, associate professor of ECE. Chris Wolfe of Chesterfield, Va., a doctoral student in ECE, designed part of the telescope and is developing an upgrade as part of his dissertation.
The roughly $10 million LWA1 is located on the Plains of San Agustin, which is also home to the National Radio Astronomy Observatory’s Very Large Array. “LWA1 is among the world’s most powerful telescopes operating at frequencies between 10 megahertz and 88 megahertz,” Ellingson said. The antennas are tent-shaped, with four wing-like sides attached to a vertical pole and a box on top that points skyward.
The telescope’s digital beamforming mode allows simultaneous observation in four independent directions, making it possible for four astronomers to use the telescope at the same time. In addition, LWA1 simultaneously produces high-sensitivity images of the entire sky every five seconds, Ellingson said. “The all-sky mode is not the ‘primary’ mode of the instrument, but it is what we show most often because most people can immediately understand what it is,” he added.
Astronomers and others will use LWA1 to study pulsars, Jupiter, the sun, and the earth’s ionosphere.
It is one of several telescopes worldwide in the race to detect the very weak broadband spectrum of the red-shifted 21-centimeter hydrogen line, which scientists expect will reveal details of the very early universe, as it existed before the first stars were formed. That race, of which Ellingson is a part, is known as the Large Aperture Experiment to Detect the Dark Ages, a collaboration with the University of New Mexico, Harvard University, and the University of California, Berkeley.
Also on deck for observation: A suspected class of powerful, but difficult to detect, intermittent astrophysical signals. Possible sources of these signals include giant flares from magnetars, exploding primordial black holes, and mergers of neutron stars in binary systems.
The LWA1 project began in 2007 as a collaborative effort between the University of New Mexico, Los Alamos National Laboratory, NASA’s Jet Propulsion Laboratory, the U.S. Naval Research Laboratory, and Virginia Tech. Funding came from NASA, the Office of Naval Research and the National Science Foundation. In December 2011, the project was designated as a University Radio Observatory by the National Science Foundation for the years 2012 to 2015, bringing a $1.5 million grant to support research efforts.