A research intern helps discover a new pulsar buried in a mountain of data

US Naval Research Laboratory (NRL) Remote Sensing Division intern Amaris McCarver and a team of astronomers discovered the first millisecond pulsar in the Glimpse-CO1 star cluster and recently published the results in The Astrophysical Journal.

Pulsars are natural laboratories for studying the behavior of matter in extreme gravitational and magnetic fields—conditions that are difficult or impossible to replicate on Earth.

They also act as natural timers. The precise timing of the observed pulses from the pulsar field offers a means of detecting gravitational waves propagating through our galaxy from merging supermassive black holes that result from galaxy collisions. Some pulsars have been observed to have an accuracy and stability comparable to our most accurate atomic clocks. These pulsars have the potential to create a “celestial GPS” system for satellite navigation in space.

McCarver’s team used images from the Karl G. Jansky Very Large Array (VLA) Low-pass Ionosphere and Transition Experiment (VLITE) to search for new pulsars in 97 star clusters.

“It was exciting so early in my career to see a speculative project work so successfully,” McCarver said. Her new approach of using VLITE images combined with images from several radio surveys at different frequencies identified multiple candidate pulsars, with the strongest candidate residing in a system known as GLIMPSE-C01.

“This type of scientific discovery is only possible because of the collaboration between NRL and the National Radio Astronomy Observatory, which has made this continuous dual-frequency capability possible at the VLA,” said Tracy E. Clarke, Ph.D., NRL Remote Sensing Division astronomer. .

“This research shows how we can use radio luminosity measurements at different frequencies to effectively find new pulsars, and that the available sky surveys, combined with the mountain of VLITE data, mean that these measurements are essentially always available. This opens the door to a new era of searching for highly scattered and highly accelerated pulsars.”

The presence of the millisecond pulsar, designated GLIMPSE-C01A, was confirmed by reprocessing archival data from the Robert C. Byrd Green Bank Telescope. Millisecond pulsars like GLIMPSE-C01A are born in supernova explosions and spun by consuming material from a companion star.

“Millisecond pulsars, or MSPs, offer a promising method for autonomous navigation of spacecraft from low Earth orbit into interstellar space, independent of ground contact and GPS availability,” said Emil Polisensky, Ph.D., an astronomer with the NRL Remote Sensing Division. “The confirmation of a new MSP identified by Amaris highlights the exciting potential for discovery with VLITE NRL data and the key role of student interns in cutting-edge research.”

McCarver received the Robert S. Hyer Research Award from the Texas Section of the American Physical Society (APS). McCarver was one of 16 summer 2023 interns at NRL DC’s Radio, Infrared, Optical Sensors Branch participating in the Science Engineering Apprenticeship Program and NREIP, Historically Black College and University/Minority Institution High Performance Computing Internship Program and the US Naval Academy Sailor Internship Program. He is majoring in physics and astronomy and plans to pursue graduate studies in astronomy.