The iconic Very Large Array (VLA) in New Mexico has been at the forefront of astrophysical research since its dedication in 1980. The Y-shaped configuration of 27 radio astronomy dishes have made key discoveries about the cosmos, while becoming a part of pop-culture in several high-profile movies.
But the aging array is due for an upgrade, one that would take advantage of advanced technology. So says the latest Decadal Survey, published by the U.S. National Academy of Sciences, which presents a consensus among researchers on the most important scientific goals and missions for the upcoming decade.
What has been proposed is the Next Generation Very Large Array (ngVLA). As envisioned, it would be a system of 263 dish antennas spread across North America but concentrated in the U.S. Southwest. Scientists say the new array would provide dramatic new scientific capabilities to the world’s astronomers. The concept was listed as the second most important ground-based project, with the U.S. Extremely Large Telescope ranking first.
“Being ranked as an important new initiative indicates that our colleagues from all specialties within astronomy and astrophysics have recognized that they need the ngVLA to meet the leading research challenges of the coming decades,” said National Radio Astronomy Observatory (NRAO) Director Tony Beasley. “We designed the ngVLA based on extensive advice from the research community and know it will be in high demand by scientists from around the world
The ngVLA next will require approval by the National Science Foundation’s National Science Board in order to be considered for funding by Congress. Optimistically, proponents say construction could begin by 2026 with early scientific observations starting in 2029 and full scientific operations by 2035.
“This Astro2020 outcome is a direct result of the close collaboration between NRAO and the greater astronomical community in developing both the broad, transformative science case and technical design of the ngVLA over the last five-plus years,” said Eric Murphy, NRAO’s Project Scientist for ngVLA. “All of the community’s hard work has clearly paid off and we now look forward to continuing this collaboration as we finalize the design and move toward achieving first light with the ngVLA,” Murphy added.
The idea for the ngVLA has been in the works since 2015. The NRAO worked with numerous scientists and engineers to develop a design to support a wide area of scientific investigations over the lifetime of the facility. Participants from around the world contributed suggestions and expertise regarding the design.
The heart of the new ngVLA is expected to remain at the at the current site of the VLA on the Plains of San Agustin in New Mexico, with several radio antennas and a signal processing center. Other antennas would be located throughout New Mexico, west Texas, eastern Arizona, and northern Mexico. More antennas will be located in clusters in Hawaii, Washington, California, Iowa, West Virginia, New Hampshire, Puerto Rico (at the site of the Arecibo Observatory), the U.S. Virgin Islands, and Canada.
Operations will be conducted at the VLA site and in nearby Socorro, New Mexico, with additional science operations planned to be in a metropolitan area yet to be determined.
Scientists say the ngVLA would be designed to have sensitivity to detect faint objects and resolving power more than 10 times greater than the current VLA. Such capabilities could address fundamental questions in all major areas of astrophysics, and would complement the Atacama Large Millimeter/submillimeter Array (ALMA) and other planned instruments such as the lower-frequency Square Kilometer Array. It also will complement the capabilities of the US-ELT optical telescopes and the orbiting James Webb Space Telescope, which will operate at infrared wavelengths and is scheduled for launch in December 2021.
The Astro 2020 describes the new array as a facility that “would be absolutely unique worldwide in both sensitivity and frequency coverage,” and concludes that “It is of essential importance to astronomy that the VLA and Very Long Baseline Array be replaced by an observatory that can achieve roughly an order of magnitude improvement in sensitivity compared to these facilities, with the ability to image radio sources on scales of arcminutes to fractions of a milliarcsecond.”
Lead image caption:
Artists’s conception of the central portion of the Next Generation Very Large Array. Credit: Sophia Dagnello, NRAO/AUI/NSF
Source: NRAO press release