Featured Research

from universities, journals, and other organizations

Star packs big gamma-ray jolt, researchers discover

Date:
October 11, 2011
Source:
University of Delaware
Summary:
In the center of the Crab Nebula, the Crab Pulsar, a spinning neutron star left over when a supernova exploded, is pulsing out gamma rays with energies never seen before -- above one hundred thousand million electron volts, according to an international scientific team that includes researchers from the University of Delaware.

Closeup of an existing VERITAS telescope camera. Currently, UD researchers Jamie Holder and his team are building 2,000 photo detectors for the new cameras for the VERITAS telescopes. The new photodetectors collect 50 percent more light than existing ones, making them more sensitive to gamma rays.
Credit: University of Delaware

In the Crab Nebula, in the constellation Taurus, a remnant of an exploded star has astrophysicists scratching their heads, reassessing their theories about gamma rays -- the highest-energy form of light, generated by subatomic particles moving close to the speed of light.

In the center of the Crab Nebula, the Crab Pulsar, a spinning neutron star left over when a supernova exploded, is pulsing out gamma rays with energies never seen before -- above one hundred thousand million electron volts, according to an international scientific team that includes researchers from the University of Delaware.

The findings are reported in the Oct. 7 issue of the journal Science. The journal article has 95 authors, including scientists from 26 institutions in five countries, who are part of the VERITAS collaboration.

VERITAS, or Very Energetic Radiation Imaging Telescope Array System, is a ground-based observatory for gamma-ray astronomy located at the Fred Lawrence Whipple Observatory in southern Arizona. It is operated by a collaboration of more than 100 scientists from 22 different institutions in the United States, Ireland, England, Germany and Canada.

"This is a really exciting and unexpected result," says Jamie Holder, assistant professor in the UD Department of Physics and Astronomy. Holder's group in the Bartol Research Institute at UD helped to construct the VERITAS telescopes. Members of the Delaware group collected a portion of the data for this study and developed some of the software used in the analysis.

"Existing theories of gamma rays from pulsars predict a sharp cut-off in the emission at high energies, around 10 thousand million electron volts. Our data show gamma rays with energies at least 20 times this, implying that the gamma rays are being produced in a different place, and probably by a different mechanism, than expected," Holder says.

Holder points out that when a gamma ray hits the atmosphere, it produces a small flash of blue light that lasts only a few billionths of a second. The VERITAS cameras take 200 photographs a second. He and his team developed software that would sift out the gamma rays from all of the background noise, representing about one-tenth of the images.

"Our software throws away all the stuff that isn't gamma rays," he says.

Holder says that he and his colleagues will keep observing the Crab Pulsar for the next few years, as the spinning star continues to wind down.

With so much radioactivity being spun out, are there any implications for us here on Earth? As Holder notes, gamma rays are ever-present in the universe, and fortunately Earth's atmosphere protects us from them.

Currently, Holder and his group at UD are in the middle of building 2,000 photo detectors for the new cameras for the VERITAS telescopes.

"The new photodetectors collect 50 percent more light than our existing ones, which will make us more sensitive to gamma rays, particularly in the energy range where the Crab Pulsar emits," Holder notes.

VERITAS is funded by the U.S. National Science Foundation, U.S. Department of Energy Office of Science, Smithsonian Institution, Natural Sciences and Engineering Research Council of Canada, Science Foundation Ireland, and Science and Technology Facilities Council of the United Kingdom.

The Bartol Research Institute is a research center in UD's Department of Physics and Astronomy. The institute's primary function is to carry out forefront scientific research with a primary focus on physics, astronomy, and space sciences.


Story Source:

The above story is based on materials provided by University of Delaware. The original article was written by Tracey Bryant. Note: Materials may be edited for content and length.


Journal Reference:

  1. The VERITAS Collaboration et al. Detection of Pulsed Gamma Rays Above 100 GeV from the Crab Pulsar. Science, 2011; DOI: 10.1126/science.1208192

Cite This Page:

University of Delaware. "Star packs big gamma-ray jolt, researchers discover." ScienceDaily. ScienceDaily, 11 October 2011. <www.sciencedaily.com/releases/2011/10/111011102109.htm>.
University of Delaware. (2011, October 11). Star packs big gamma-ray jolt, researchers discover. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2011/10/111011102109.htm
University of Delaware. "Star packs big gamma-ray jolt, researchers discover." ScienceDaily. www.sciencedaily.com/releases/2011/10/111011102109.htm (accessed August 23, 2014).

Share This




More Space & Time News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Newsy (Aug. 21, 2014) Russian cosmonauts say they've found evidence of sea plankton on the International Space Station's windows. NASA is a little more skeptical. Video provided by Newsy
Powered by NewsLook.com
Space to Ground: Hello Georges

Space to Ground: Hello Georges

NASA (Aug. 18, 2014) Europe's ATV-5 delivers new science and the crew tests smart SPHERES. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Tiny Satellites, Like The One Tossed From ISS, On The Rise

Tiny Satellites, Like The One Tossed From ISS, On The Rise

Newsy (Aug. 18, 2014) The Chasqui I, hand-delivered into orbit by a Russian cosmonaut, is one of hundreds of small satellites set to go up in the next few years. Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, August 15, 2014

This Week @ NASA, August 15, 2014

NASA (Aug. 15, 2014) Carbon Observatory’s First Data, ATV-5 Delivers Cargo, Cygnus Departs Station and more... Video provided by NASA
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

More Coverage


Crab Pulsar Emits Light at Highest Energies Ever Detected in a Pulsar System, Scientists Report

Oct. 6, 2011 An international collaboration of scientists has detected the highest energy gamma rays ever observed from a pulsar, a highly magnetized and rapidly spinning neutron star. The Very Energetic ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins