Thousands of Volunteers Helped Identify Gamma-Ray Source
Artist’s impression of PSR J2039−5617 and his companion. The binary system consists of a rapidly rotating neutron star (right) and a star companion that makes up about a sixth of the mass of our sun (left). The star is deformed by the strong tidal forces of the neutron star and heated by the gamma radiation (magenta) of the neutron star. Knispel / Clark / Max Planck Institute for Gravitational Physics / NASA GSFC
The origin of a mysterious gamma-ray source that has puzzled astronomers for seven years has been identified thanks to donated computer power from thousands of volunteers. The Einstein @ Home project is a distributed computer project that uses the processing power of volunteer computers to solve great puzzles in science, and it has paid off in the form of this new discovery.
In 2014, the PSR J2039−5617 object, which emits x-rays, gamma rays, and light, was discovered. The researchers thought this object was a neutron star and a smaller star in a binary system, but they needed more data to be sure.
“It has been suggested for years that there is a pulsar, a rapidly rotating neutron star, at the heart of the source we now know as PSR J2039−5617,” said Lars Nieder, Ph.D. Student at the Max Planck Institute for Gravitational Physics and co-author of the study, in a statement. “But it was only possible to lift the veil and discover the gamma-ray pulsations with the computing power that tens of thousands of volunteers had donated to Einstein @ Home.”
The researchers first imaged the object with optical telescopes and found that the double star had an orbital time of 5.5 hours. However, they needed more data to know what gamma rays are being emitted from the object. Then they turned to Einstein @ Home.
Using the free processing cycles of the CPUs and GPUs on the computers of tens of thousands of volunteers, the researchers spent 11 years browsing data from NASA’s Fermi gamma-ray space telescope. They looked for periodic pulses from gamma ray photons and were able to capture regular pulses from the neutron star.
According to the Max Planck Institute for Gravitational Physics, where the research was carried out, the search on a single computer core would have taken 500 years. Thanks to the Einstein @ Home volunteers, they were able to complete the search in two months.
Now the team wants to conduct more searches for gamma-ray sources over the distributed computer network. “We know of dozens of similar gamma-ray sources found by the Fermi Space Telescope whose true identity is still unclear,” said Professor. Dr. Bruce Allen, Director at the Max Planck Institute for Gravitational Physics and founder of Einstein @ Home. “Many could be pulsars hidden in binary systems and we will continue to track them with Einstein @ Home.”