Fermi Finds 16 New Pulsating Neutron Stars

A team of international researchers, working in collaboration with experts from the Naval Research Laboratory (NRL) Space Science Division have recently announced that the Fermi telescope managed to identify 16 new, bright sources of gamma-rays, in 16 pulsating neutron stars. For the discovery, blind frequency searches were conducted based on data provided by the Large Area Telescope (LAT), the largest instrument aboard Fermi, most notably on sparse photon readings.

The photons that were detected by the LAT were tens of millions to hundreds of billions times more energetic than the ones in the visible wavelength range, which we can observe with the naked eye. They had energies ranging between 20 Mega-electron-volts (MeVs) and 300 Giga-electron-volts (GeVs), the science team that handles the data provided by the observatory reports.

“Fermi has truly unprecedented power for discovering and studying gamma ray pulsars. Since the demise of the Compton Gamma Ray Observatory [one of NASA's four Great Observatories] a decade ago, we've wondered about the nature of unidentified gamma-ray sources it detected in our galaxy. These studies from Fermi lift the veil on many of them,” NRL astrophysicist Paul Ray, who has been part of the team involved in the new studies, says.

A new, related paper also reveals eight Galactic millisecond pulsars (MSP), which are neutron stars spinning several hundreds of times per second. Despite their speeds, they generate a magnetic field about 10,000 times weaker than their slower-spinning counterparts. Still, Fermi observations show, they are fully capable of generating large and highly-energetic gamma-rays.

“The Fermi LAT makes it possible for us to pinpoint neutron stars. The combination of a very large collecting area, large field of view, and precision timing from an on-board Global Positioning System receiver enables the LAT to see sources that were far beyond the reach of previous gamma-ray telescopes,” NRL Space Science Division astrophysicist and LAT Commissioner Eric Grove concludes.