Einstein@Home Discovers a Radio-quiet Gamma-ray Millisecond Pulsar

Millisecond pulsars (MSPs) are old neutron stars that spin hundreds of times per second and appear to pulsate as their emission beams cross our line of sight. To date, radio pulsations have been detected from all rotation-powered MSPs. In an attempt to discover radio-quiet gamma-ray MSPs, we used the aggregated power from the computers of tens of thousands of volunteers participating in the Einstein@Home distributed computing project to search for pulsations from unidentified gamma-ray sources in Fermi Large Area Telescope data. This survey discovered two isolated MSPs, one of which is the only known rotation-powered MSP to remain undetected in radio observations. These gamma-ray MSPs were discovered in completely blind searches without prior constraints from other observations, raising hopes for detecting MSPs from a predicted Galactic bulge population.

References

Abdo A, Ackermann M, Ajello M, Anderson B, Atwood W, Axelsson M . Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT. Science. 2009; 325(5942):840-4. DOI: 10.1126/science.1175558. View

Hessels J, Ransom S, Stairs I, Freire P, Kaspi V, Camilo F . A radio pulsar spinning at 716 Hz. Science. 2006; 311(5769):1901-4. DOI: 10.1126/science.1123430. View

Abdo A, Ackermann M, Ajello M, Atwood W, Axelsson M, Baldini L . A population of gamma-ray millisecond pulsars seen with the Fermi Large Area Telescope. Science. 2009; 325(5942):848-52. DOI: 10.1126/science.1176113. View

Pletsch H, Guillemot L, Fehrmann H, Allen B, Kramer M, Aulbert C . Binary millisecond pulsar discovery via gamma-ray pulsations. Science. 2012; 338(6112):1314-7. DOI: 10.1126/science.1229054. View

Ackermann M, Albert A, Anderson B, Atwood W, Baldini L, Barbiellini G . Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data. Phys Rev Lett. 2015; 115(23):231301. DOI: 10.1103/PhysRevLett.115.231301. View