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.
View the original article with all of the images on UD's UDaily news service here: http://www.udel.edu/udaily/2012/oct/star-gamma-rays-100711.html
Tracey Bryant | Newswise Science News
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences