Secrets of double pulsars revealed
McGill researcher's study published in Nature April 29
The intricate dynamics of an extraordinary double pulsar system are made clearer by the work of Scott Ransom of McGill University, in a study appearing in the April 29 issue of the scientific journal Nature.
The study, conducted in collaboration with Frederick Jenet of Jet Propulsion Laboratory in Pasadena, California, could improve the understanding of pulsar formation and emissions and even of gravitational theories.
Pulsars are spinning neutron stars that send out beams of energy like a lighthouse. The binary system J0737-3039, discovered last year, is the first double pulsar ever seen by astronomers. The energy beams in this system seem to interact as they spin around each other, providing a useful way to determine the geometry of the orbits.
Ransom, a postdoctoral researcher in McGill's Department of Physics, and Jenet have shown how one of the pulsars in this double pulsar system effectively turns the radio emission of the other pulsar on and off with time.
Until now, 30 years of research has been unable to determine the mechanism producing a pulsar's radio emissions. The fact that these two pulsars influence each other's radio pulses makes the system a truly unique natural laboratory for the investigation of the emission processes of pulsars.
"If the geometry of the double pulsar system is as we suggest," says Ransom, "it should lead us to a much better understanding of how these systems emit their radiation and how they form in the first place. Knowledge of the geometry could also prove essential for the exquisite tests of theories of gravitation that will come from J0737-3039 due to the huge gravitational wells these massive objects create."
But time to use nature's laboratory is short: Jenet and Ransom predict that because of distortions in space around the pulsars, the system will disappear from our view in approximately 15 years.
The double pulsar system is located about 2,000 light years, or 10 million billion miles, from Earth. Ransom and Jenet based their research on observations made at the Green Bank Telescope in West Virginia.
