200,000 home PCs help discover 24 pulsars
Scientists have used the combined computing power of 200,000 home PCs around the world, to take an inventory of the Milky Way and add 24 pulsars to the cosmic census.
Pulsars are the remnants from explosions of massive stars. They are strongly magnetised and extremely dense neutron stars.
The Einstein@Home project connects home and office PCs of volunteers from around the world to a global supercomputer.
Using this computer cloud, an international team lead by scientists from the Max Planck Institutes for Gravitational Physics and for Radio Astronomy discovered 24 pulsars – extraordinary stellar remnants with extreme physical properties.
These can be used as testbeds for Einstein's general theory of relativity and could help to complete our picture of the pulsar population, researchers said.
"Through the participation of the public, we discovered 24 new pulsars in our Milky Way, which had previously been missed - and some of them are particularly interesting," said Benjamin Knispel, lead author of the study published in The Astrophysical Journal.
Pulsars rapidly rotate and emit a beam of radio waves along their magnetic field axis – similar to the spotlight of a lighthouse. If the radio wave beam points towards Earth, the pulsar can be observed.
Large and sensitive radio telescopes are required to discover the weak signals from new pulsars. Knispel and his colleagues analysed data from the Parkes Multi-beam Pulsar Survey, conducted from 1997 to 2001, with the 64-meter antenna of CSIRO's Parkes radio telescope in southeast Australia.
"The search for new radio pulsars is very computer intensive. To determine the a prior unknown characteristics of the pulsar, eg, its distance or its rotation period, we have to very finely comb through wide parameter ranges," said Knispel.
Each week, 50,000 volunteers from around the world "donate" idle compute cycles on their 200,000 home and office PCs to Einstein@Home.
Together they combine to yield a sustained computing power of around 860 teraFLOPs per second. This places Einstein@Home on par with the world's fastest supercomputers.
The analysis of the archival Parkes data was completed in eight months, while the same task would have taken a single CPU core more than 17,000 years, researchers said.
Raw computing power was not the only important factor to discover the two dozen new pulsars. The development of new post-processing methods proved to be just as crucial.
The recorded data often contain pulsar-like, man-made interference signals. The astronomers employed new methods that allowed them to discover pulsars previously masked by the presence of these interference signals.