Astrophysicists have identified a mysterious galactic source of gamma rays Record-breaking: a heavy neutron star with a dizzyingly orbiting very low-mass companion.

Using novel data analysis methods running on some 10,000 graphics cards in the Einstein @ Home distributed computing project, the team identified the neutron star for its gamma rays that pulsaban regularly in a deep search of data from NASA’s Fermi satellite.

Surprisingly, the neutron star it is completely invisible on radio waves. The binary system was characterized with an observation campaign across the entire electromagnetic spectrum and breaks several records.

“The binary star system and the neutron star at its heart, now known as PSR J1653-0158, set new records“explains in a statement Lars Nieder, a doctoral student at the AEI (Albert Einstein Institute) in Hannover and first author of the study published in Astrophysical Journal Letters.

“We have discovered the galactic dance of a superheavyweight to a flyweight: At a little more than twice the mass of our Sun, the neutron star is extraordinarily heavy. Its companion has about six times the density of lead, but only around 1% of the mass of our Sun. This ‘strange couple’ orbits every 75 minutes, faster than all known comparable binaries“.

The neutron star too rotates around its own axis at more than 30,000 rpm, which makes it one of the fastest rotating. At the same time, his magnetic field, generally extremely strong in neutron stars, is exceptionally weak.

The findings were made possible by the observation at many wavelengths and the use of the computational power donated to Einstein @ Home.

“In binary systems like the one we have now discovered, pulsars are known as ‘black widows’ because, like the spiders of the same name, they eat their partners, so to speak, “explains Colin Clark of the Jodrell Bank Center for Astrophysics and co-author of the study. vaporizes your partner with its radiation and a wind of particles, filling the star system with plasma that is impenetrable to radio waves. “

The gamma rays, on the other hand, are not stopped by these plasma clouds. The Large Area Telescope (LAT) aboard NASA’s Fermi Gamma-ray Space Telescope detects this radiation.

The team used data from 2014, further observations with the William Herschel Telescope on La Palma, and the precise position of the sky determined by the Gaia satellite to aim and focus computing power of the volunteer distributed computing project Einstein @ Home. This also provided a more complete sketch of companion star.

Improving on previous methods developed for this purpose, they enlisted the help of tens of thousands of volunteers to search over a decade of Fermi LAT archival data in search of periodic pulsations. Volunteers donated idle compute cycles on their computers’ graphics cards (GPUs) to Einstein @ Home. In less than two weeks, the team made a discovery that would have taken centuries of time computing on a conventional computer.