One dozen and one neutron stars
With the help of tens of thousands of volunteers the distributed computing project Einstein@Home discovers 13 new gamma-ray pulsars
An analysis that would have taken more than a thousand years on a single computer has found within one year more than a dozen new rapidly rotating neutron stars in data from the Fermi gamma-ray space telescope. With computing power donated by volunteers from all over the world an international team led by researchers at the Max Planck Institute for Gravitational Physics in Hannover, Germany, searched for tell-tale periodicities in 118 Fermi sources of unknown nature. In 13 they discovered a rotating neutron star at the heart of the source. While these all are – astronomically speaking – young with ages between tens and hundreds of thousands of years, two are spinning surprisingly slow – slower than any other known gamma-ray pulsar. Another discovery experienced a “glitch”, a sudden change of unknown origin in its otherwise regular rotation.
Additional information: Who made the discoveries?
The discoveries were enabled by tens of thousands of Einstein@Home volunteers who have donated their CPU time to the project. Without them this survey could not have been performed and these discoveries could not have been made. The team is especially grateful to those volunteers whose computers discovered the 13 pulsars reported in the ApJ publication (where the volunteer’s name is unknown or private, we give the Einstein@Home username in quotation marks):
PSR J0002+6216: James Drews of UW-Madison, WI, USA and Ralph Elwell of Richland, WA, USA; PSR J0359+5414: Whelton A. Miller III, Lincoln University of Pennsylvania & University of Pennsylvania, USA; the ATLAS Cluster, AEI, Hannover, Germany and Philip “Delty” Horney of the GPU Users Group, Fort Wright, KY, USA; PSR J0631+0646: Katagiri, Atsushi of Kawasaki, Japan and Nicholas Huwar of Houston, TX, USA; PSR J1057−5851: Syracuse University HTC Campus Grid, NY, USA; Igor Yakushin of Chicago, IL, USA and the LIGO Laboratory, USA; PSR J1105−6037: The ATLAS Cluster, AEI, Hannover, Germany and Syracuse University HTC Campus Grid, NY, USA; PSR J1350−6225: Petr Ruzicka of Brno, Czech Republic and Bryden Kanngiesser of Calgary, Canada; PSR J1528−5838: “fred c” and Gabriel Vasquez of Miami, FL, USA; PSR J1623−5005: Lars Bollwinkel, of Kiel, Germany and Greg Dorais of Martinez, CA, USA; PSR J1624−4041: Xio of NYC and Hung Tran of Chandler, AZ, USA; PSR J1650−4601: Syracuse University HTC Campus Grid, NY, USA and Eric Schwartz of Vashon Island, WA, USA; PSR J1827−1446: The ATLAS Cluster, AEI, Hannover, Germany; Igor Yakushin of Chicago, IL, USA and the LIGO Laboratory, USA; PSR J1844−0346: Aurélien FAUCHEUX of Antibes, France and Roger Gulbranson, Ph.D. of Wickliffe, OH, USA; PSR J2017+3625: Kurt Gramoll, Ph.D., University of Oklahoma, OK, USA and Michael Brandau, of Kassel, Germany.
Additional information: Einstein@Home quick facts
Einstein@Home is a distributed volunteer computing and connects computers and smartphones from the general public from all over the world. The project volunteers donate spare computing time on their devices. So far more than 440,000 volunteers have participated, making Einstein@Home one of the largest projects of this kind. The aggregate computing power is about 1.6 petaFLOPS, which would secure Einstein@Home a position among the top 60 on the TOP500 list of supercomputers.
Since 2005, Einstein@Home has examined data from the gravitational wave detectors within the LIGO-Virgo-Science Collaboration (LVC) for gravitational waves from unknown, rapidly rotating neutron stars. As of March 2009, Einstein@Home has also been involved in the search for signals from radio pulsars in observational data from the Arecibo Observatory in Puerto Rico and the Parkes Observatory in Australia. Since the first discovery of a radio pulsar by Einstein@Home in August 2010, the global computer network has discovered 55 new radio pulsars. A search for gamma-ray pulsars in data of the Fermi satellite was added in August 2011. It has discovered 21 new gamma-ray pulsars as of today.
Scientific supporters are the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, Hanover) and the Center for Gravitation and Cosmology at the University of Wisconsin-Milwaukee with financial support from the National Science Foundation and the Max Planck Society.
Additional information: Searching step by step – the new search methods
Their new methods improve the search sensitivity without increasing the associated computational costs. They consist of an initial search stage more sensitive than in any other Einstein@Home gamma-ray search before. The initial search produces a number of interesting candidates which are then followed up on with an even more sensitive second stage, which zooms in and narrows down the uncertainty in the pulsars physical properties. The final step of the search is not performed on Einstein@Home, but on the Atlas computer cluster at the Max Planck Institute for Gravitational Physics in Hannover.