Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neutron stars in the computer cloud

30.08.2013
Einstein@Home discovers 24 new pulsars in archival data

The combined computing power of 200,000 private PCs helps astronomers take an inventory of the Milky Way. The Einstein@Home project connects home and office PCs of volunteers from around the world to a global supercomputer.


Einstein@Home searches for unknown neutron stars through their pulsed radio emission. This image shows an artist's impression of a neutron star, surrounded by its strong magnetic field (blue). It emits a narrow beam of radio waves (magenta) above its magnetic poles. When the star's rotation sweeps these beams over the Earth, the neutron star can be detected as a radio pulsar.

© NASA

Using this computer cloud, an international team lead by scientists from the Max Planck Institutes for Gravitational Physics and for Radio Astronomy analysed archival data from the CSIRO Parkes radio telescope in Australia. Using new search methods, the global computer network 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.

“We could only conduct our search thanks to the enormous computing power provided by the Einstein@Home volunteers,” says Benjamin Knispel, researcher at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) in Hannover, and lead author of the study now published in The Astrophysical Journal. “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.”

Complex searches for cosmic lighthouses

Pulsars are the remnants from explosions of massive stars. They are strongly magnetized and extremely dense neutron stars. They 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 priori unknown characteristics of the pulsar, e.g., its distance or its rotation period, we have to very finely comb through wide parameter ranges,” says Knispel.

Pulsar searches with public participation

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.

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.

Unusual species in the pulsar zoo

The researchers used the radio telescopes near Parkes, at the Jodrell Bank Observatory, and at Effelsberg for follow-up observations and to characterize their discoveries in more detail. “There are different kinds of pulsars, just like there are different animal species in a zoo. Some are more common than others – in some cases, only a handful of specimens are known,” explains Ralph Eatough, scientist at the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn and second author of the publication.

Pulsars in binary systems are of particular interest to the astronomers. That is because these objects allow insights into their formation history and because they can be used as testbeds for Einstein's general theory of relativity. However, discovering them is even more computationally demanding than the already challenging task of finding isolated pulsars. Tracking down their complex signals in the data increases the computing costs that far exceeds the computing capacities at the two Max Planck Institutes.

Out of the 24 pulsars discovered by Einstein@Home, six are in binary systems orbiting the common centre of mass with their stellar partner. These systems form only under very specific astrophysical conditions, which the scientists can now reconstruct more precisely. One of the newly discovered pulsars has an unusually long orbital period of about 940 days – the fourth longest known. In the future, it could be used as a testbed for Einstein's general theory of relativity.

Some of the pulsars that were discovered appear to switch off their radio emission for some minutes or hours. “This phenomenon has been observed before, but it is not yet fully understood. Further investigations could help to improve our understanding of the processes in the pulsars' strong magnetic fields, which power their radio emission,” says Eatough.

It is not only important to find these exceptional objects, but also to discover “normal” pulsars. The Parkes Multi-beam Pulsar Survey is often used as reference for numerical simulations of our Galaxy's pulsar population. Only by finding all pulsars hidden in the data, can astronomers draw precise conclusions about the entirety of pulsars in the Milky Way.

A computing model for the future

“Our discoveries prove that distributed computing projects like Einstein@Home can play an important role in modern, data-based astronomy,” says Bruce Allen, director of Einstein@Home and director at the AEI. “We expect distributed computing to become increasingly important for astronomical data analysis in the future. Einstein@Home is also very well prepared for the increasing mobility of computing power,” says Allen. Recently, volunteers can not only sign up their PCs for the project, but also help to find new radio pulsars with their Android-based smartphones and tablets.

“In one of our next projects, we would like to use Einstein@Home's computing power to search for pulsars in compact binary systems using 'fresh' data from our very sensitive radio telescope near Effelsberg,” says Michael Kramer, director at the MPIfR. Such systems enable tests of the general theory of relativity: its effects are strongest when massive bodies orbit each other at a small distance. Michael Kramer is looking forward to the search: “Who knows what surprises are waiting for us.”

Background information on Einstein@Home

This distributed volunteer computing project connects PC users from all over the world, who voluntarily donate spare computing time on their home and office computers. It has more than 340,000 participants and is one of the largest projects of this kind. Scientific supporters are the Center for Gravitation and Cosmology at the University of Wisconsin-Milwaukee and the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, Hanover) with financial support from the National Science Foundation and the Max Planck Society.

Since 2005, Einstein@Home has analysed data from the gravitational wave detectors within the LIGO-Virgo-Science Collaboration (LVC) for gravitational waves from unknown, rapidly rotating neutron stars.

Since 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 CSIRO's Parkes radio telescope in Australia. Since the first discovery of a radio pulsar by Einstein@Home in August 2010, the global computer network has discovered almost 50 new radio pulsars.

A new search for gamma-ray pulsars in data of the Fermi satellite was added in August 2011; the project is looking for, among other things, the first millisecond pulsar, visible only in the gamma-ray range.

Contact

Dr. Benjamin Knispel
Press & public outreach officer
Max Planck Institute for Gravitational Physics (Hannover), Hannover
Phone: +49 511 762-19104
Email: benjamin.knispel@­aei.mpg.de
Dr. Norbert Junkes
Press & public outreach officer
Max Planck Institute for Radio Astronomy, Bonn
Phone: +49 228 525-399
Fax: +49 2257 301-105
Email: njunkes@­mpifr-bonn.mpg.de
Original publication
Knispel, B. et al
Einstein@Home Discovery of 24 Pulsars in the Parkes Multi-beam Pulsar Survey
The Astrophysical Journal, 774, 93 (2013)

Dr. Benjamin Knispel | Max-Planck-Institute
Further information:
http://www.mpg.de/7511374/einstein_at_home_pulsar_discoveries?filter_order=L&research_topic=

More articles from Physics and Astronomy:

nachricht New type of low-energy nanolaser that shines in all directions
18.12.2018 | Eindhoven University of Technology

nachricht NASA research reveals Saturn is losing its rings at 'worst-case-scenario' rate
18.12.2018 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New megalibrary approach proves useful for the rapid discovery of new materials

Northwestern discovery tool is thousands of times faster than conventional screening methods

Different eras of civilization are defined by the discovery of new materials, as new materials drive new capabilities. And yet, identifying the best material...

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

New megalibrary approach proves useful for the rapid discovery of new materials

19.12.2018 | Materials Sciences

Artificial intelligence meets materials science

19.12.2018 | Materials Sciences

Gut microbiome regulates the intestinal immune system, researchers find

19.12.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>