MRI: Development of the OVRO-LWA - A Low Frequency Radio Interferometric All-Sky Telescope

California Institute Of Technology, Pasadena CA

Investigators

Abstract

The concept of a radio telescope typically evokes imagery of giant dishes moving in unison, peering towards some small part of the sky. This notion is outdated - the Owens Valley Radio Observatory - Long Wavelength Array (OVRO-LWA) combines the signals from hundreds of small, cheap antennas to image the entire sky instantaneously, representing a revolutionary new generation of radio telescope. The resulting data stream is enormous (12 Petabytes per day), but Moore's Law has finally made it possible to continuously process and distill these data. By imaging all the sky, all the time, the OVRO-LWA can deliver a number of key science goals simultaneously. It can scan thousands of nearby stellar systems for the radio signature of exoplanet magnetospheres, a key ingredient for planetary habitability. It can probe our Cosmic Dawn, the earliest stages of our Universe when the very first stars formed. It will search the sky on nanosecond timescales for evidence of the highest energy cosmic rays, and it will provide continuous monitoring of the Sun (which is relevant for space weather), and Jovian system. This proposed program will progress the OVRO-LWA from a proof of concept to a continuously operational facility, and the most powerful radio telescope on the planet operating at low radio frequencies (<100 MHz). The addition of 64 antennas will extend maximum baselines from 1.5 km to 2.6 km and will improve the snapshot sensitivity of the array by a factor of 3. The telescope receiver electronics will be replaced with a new generation of electronics board that can maintain 80 dB isolation between each of the 704 signal paths (352 dual polarization antennas), an essential requirement for detecting the weak polarized signatures of exoplanets as well as the Cosmic Dawn signal buried within the bright contaminating radio emission of our own Galaxy. The digital backend will be the most versatile instrument ever built for radio astronomy, being able to simultaneously image the entire sky, form 12 high time resolution beams that can be instantaneously repointed in any direction on the sky, and search the raw data from the telescope for cosmic ray radio showers lasting a few nanoseconds in duration. The additional installation of a 4.4 PB storage system will allow the OVRO-LWA to continuously execute these modes of operation simultaneously. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.