Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

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

10.04.2015

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; Bustamanteramirez.1@osu.edu

Written by Pam Frost Gorder, (614) 292-9475; Gorder.1@osu.edu

Media Contact

Pam Frost Gorder
Gorder.1@osu.edu
614-292-9475

 @osuresearch

http://news.osu.edu 

Pam Frost Gorder | EurekAlert!

More articles from Physics and Astronomy:

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

nachricht What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto

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: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>