Gravitational wave sources: NSF supports cross-Texas collaboration

Image: University of Texas Rio Grande Valley

Six years ago, two Texas astronomers — Texas A&M University’s Lucas Macri and the University of Texas Rio Grande Valley’s Mario Díaz — teamed with Universidad Nacional de Córdoba astronomer Diego Garcia Lambas in an effort to get ahead of what they saw as the next big cosmic thing: gravitational-wave astronomy.

In the years since, their collaboration, called the Transient Optical Robotic Observatory of the South (TOROS), has searched for electromagnetic counterparts to gravitational-wave sources using a variety of telescopes across the globe while also pursuing funding opportunities to establish their own state-of-the-art telescope and camera in one of the best astronomical sites on Earth, Cordón Macón in northwestern Argentina.

Their persistence recently paid off in the form of a $516,000 award from the National Science Foundation, $175,000 of which will be earmarked to Texas A&M astronomers Darren DePoy and Jennifer Marshall and their team within Texas A&M’s Charles R. ’62 and Judith G. Munnerlyn Astronomical Instrumentation Laboratory. They will use the funds to build a prime-focus corrector, a precisely crafted set of lenses that will maximize the field of view of a top-of-the-line 100-megapixel charge-coupled device (CCD) camera, which will serve as the dedicated instrument of the TOROS telescope.

Construction on Cordón Macón started earlier in 2019, thanks to funding provided by the Argentine National Science Foundation and previous NSF funding to Diaz as the overall principal investigator of the TOROS project. The telescope is expected to be operational in early 2020, initially relying on more modest instrumentation while DePoy and Marshall build, integrate and test the prime-focus camera.

“TOROS will make important contributions to the follow-up of gravitational wave sources and will help develop the next generation of big data astronomers across diverse communities in Aggieland, Argentina and the Rio Grande Valley,” Macri said. “There are many challenges associated with searching large areas of the sky for fast-evolving astronomical sources, making this a great interdisciplinary astrostatistics project for the Texas A&M College of Science. We are grateful for the bi-national support that this project has received.”

When a pair of neutron stars collided in the galaxy NGC 4993 in 2017 in perhaps the best-known gravitational wave event to date, Macri and his TOROS collaborators used the T80-South telescope located at the Cerro Tololo Inter-American Observatory (CTIO) in Chile and the Bosque Alegre telescope located in Argentina to study the fast-fading kilonova at various wavelengths, which is useful to rule out various models for the explosion. He presented their results, published in The Astrophysical Journal Letters, as part of a Gravitational Wave Astrophysics Conference sponsored by the International Astronomical Union and hosted by Louisiana State University.

Armed with the recent NSF funding and the collaboration’s collective expertise, Texas A&M astronomers are confident TOROS’ own telescope will soon be in the universal hunt.

“We look forward to developing this premier instrument for TOROS and deploying it on Cordón Macón,” said Marshall, who along with DePoy, Macri and then-Ph.D. student Ryan Oelkers traveled to Argentina in mid-2013 to carry out test astronomical observations from the area.

“The Macón site has a lot of promise, as evidenced by its finalist status as a possible site for the billion-dollar European Extremely Large Telescope,” added DePoy, who previously served as project scientist for the 570-megapixel camera behind the U.S. Department of Energy- and NSF-funded Dark Energy Survey.

More from the College of Science