Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Cosmic debris: Study looks inside the universe's most powerful explosions


Finding sets the stage for discoveries from the next generation of neutrino telescopes

A new study provides an inside look at the most powerful explosions in the universe: gamma-ray bursts.

These rare explosions happen when extremely massive stars go supernova. The stars' strong magnetic fields channel most of the explosion's energy into two powerful plasma jets, one at each magnetic pole. The jets spray energetic particles for light-years in both directions, at close to light speed.

On Earth, we detect bits of the resulting debris as gamma rays. Researchers also suspect--but haven't been able to prove conclusively--that GRBs are the source of at least some of the cosmic rays and neutrinos that pepper our planet from space.

Now, physicists at The Ohio State University and their colleagues have begun to answer that question. By building some of the most detailed computer simulations ever made of a GRB jet's internal structure, they have been able to model particle production inside of it.

Their finding--that the non-uniform internal structure of the jets is key to determining the emission of the different kinds of astroparticles--appears online April 10 in the journal Nature Communications. The study also raises new questions that can be answered only by the next generation of neutrino telescopes.

Mauricio Bustamante, a Fellow of the Center for Cosmology and AstroParticle Physics at Ohio State, explained that the new computer model is a natural outgrowth of recent findings in astroparticle physics, such as the first confirmed cosmic neutrinos detected at the IceCube Neutrino Observatory at the South Pole in 2013.

"Previously, the details of the non-uniformity of the GRB jets were not too important in our models, and that was a totally valid assumption--up until IceCube saw the first cosmic neutrinos a couple of years ago," he said. "Now that we have seen them, we can start excluding some of our initial predictions, and we decided to go one step further and do this more complex analysis."

With partners at Penn State and the DESY national research center in Germany, Bustamante wrote new computer code to take into account the shock waves that are likely to occur within the jets. They simulated what would happen when blobs of plasma in the jets collided, and calculated the particle production in each region.

In their model, some regions of the jet are denser than others, and some plasma blobs travel faster than others.

Bustamante offered the analogy of the plasma jet as a long highway, albeit one where the cars are traveling at different speeds close to the speed of light.

"Everywhere on the highway there are fast-moving cars, but some of them will be fast sports cars, while others will be extra-fast Formula 1 racers. They will collide all over the highway, and when they do they will create debris. The debris always contains neutrinos, cosmic rays and gamma rays, but, depending on where the collisions occurred, one of these will typically dominate the emission," he said.

"If the cars collide close to the beginning of the highway, where the concentration of cars is higher, the debris will be mostly neutrinos. As they race along the highway, the concentration of cars goes down, and so when a collision occurs halfway through the length of the highway, the debris will be mostly cosmic rays. Further down the road, the concentration is even lower, and the gamma rays that we observe at Earth are produced in the collisions at this stage."

The amount of debris that reaches Earth depends on how energetic the star is and how far away it is.

One implication of the model is that the rate of neutrino production in GRBs might be lower than previously thought, so only a minimal number--say, 10 percent--of neutrinos detected on Earth are likely to come from GRBs. The density of neutrinos that reach Earth is called the neutrino flux, and the model predicts that the likely neutrino flux from GRBs is below the threshold of detection for today's neutrino telescopes.

"We expect that the next generation of neutrino telescopes, such as IceCube-Gen-2, will be sensitive to this minimal flux that we're predicting," Bustamante said. Then astrophysicists can use the model to refine notions of GRB internal structure and better understand the sources of cosmic particles detected on Earth.

Co-authors on the paper were Philipp Baerwald and Kohta Murase of the Institute for Gravitation and the Cosmos at Penn State and Walter Winter of DESY in Germany.

This work was funded by NASA, the German Research Foundation, and the U.S. National Science Foundation.

Contact: Mauricio Bustamante, (614) 292-0734;

Written by Pam Frost Gorder, (614) 292-9475;

Media Contact

Pam Frost Gorder


Pam Frost Gorder | EurekAlert!

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

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 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

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...

Im Focus: New Products - Highlights of COMPAMED 2016

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...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'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...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>