A new radio telescope was recently activated in California, based at Caltech’s Owens Valley Radio Observatory (OVRO). It’s the Owens Valley Long Wavelength Array (OV-LWA), a set of 256 small antennas developed by a consortium led by Caltech that includes NASA’s JPL, Harvard University, the University of New Mexico, Virginia Tech, and the Naval Research Laboratory. Its purpose is to observe the entire sky 24/7 at long radio wavelengths.
The OV-LWA, with its low cost antennas of less than a meter (about 3′) in diameter, can be used for a wide range of observations. Among its goals there are the study of the early universe but also the space weather, in particular the interaction between the stars and their planets.
The 256 antennas are spread over a large area of the California desert providing the sensitivity of a single antenna of 100 meters (more than 300′) in diameter. There’s a huge cost advantage but also in the field of view: a single antenna could observe only a small part of the sky while the OV-LWA can see it all at once.
Due to its sensitivity and field of view, the OV-LWA produces a huge amount of data, about 25 TeraByte per day, the equivalent of more than 5,000 DVDs. To manage them a supercomputer is needed, the one of the LEDA (Large-Aperture Experiment to Detect the Dark Ages) project in New Mexico, located at the other LWA radio telescope and close to the larger VLA (Very Large Array).
The signals from the antenna combined by the supercomputer of the LEDA project are then sent to another computer cluster, the All-Sky Transient Monitor (ASTM) developed at Caltech and JPL. It’s this second computer cluster that produces the images in real time.
It’s thanks to these increasingly powerful supercomputers that now it’s possible to build these sparse array. These systems such as the two LWAs represent in some ways the future of astronomy and one of them, called the Low-Frequency Aperture Array (LFAA) will be part of the SKA (Square Kilometre Array), one of the most ambitious astronomical projects under development.
The Earth’s atmosphere blocks or reflects some radio wavelengths, setting limits to this kind of observations. The ideal, as for other types of telescopes, would be building an array in space or in a place without an atmosphere that interfere such as the Moon.
[ad name=”eBayUSUKAstronomy”]
