Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Of harps, Christmas trees, a wandering star and the mysterious streams of cosmic rays


Researchers at the Leibniz Institute for Astrophysics in Potsdam (AIP), and the Max Planck Institute for Astrophysics in Garching (MPA), have investigated galactic radio objects that adopt shapes such as Christmas trees and harps. With the help of these objects, the old question of how cosmic radiation propagates could be answered.

The inner region of our Milky Way galaxy is characterised by large amounts of warm gas, cosmic-rays and enhanced radio emission. “Astronomers have been observing planar radio-emitting magnetised structures in the galactic centre for almost twenty years.

Radio synchrotron harp and Christmas tree in the galactic centre.

T. Thomas (AIP) / MeerKat

Recent observations with the MeerKAT telescope in South Africa show that these are organised into groups of almost parallel filaments, that span over a length of several light years,” reports Timon Thomas from the AIP, the leading author of the study.

“The filaments are seemingly sorted by their length, so that they look like the strings of a harp.” Hence, researchers from Potsdam and Garching called these objects radio synchrotron harps. Synchrotron is the name of the mechanism that generates the radio emission. It arises when charged particles like electrons are accelerated in magnetic fields.

“The observed structures are created when massive stars or pulsars fly through an ordered magnetic field and discharge cosmic ray particles along their path into these magnetic fields,” explains co-author Christoph Pfrommer from AIP. “The particles propagate along the magnetic field lines, usually transverse to the stellar orbit, causing the magnetic fields in the radio regime to light up and appear like the strings of a harp.”

So far, the exact transport process of the particles along these strings has been a mystery. The researchers now assume that the individual strings show a chronological sequence in which the particles have spread along the magnetic field lines from their point of release.

If this propagation was a diffusion process, the structures seen in the radio observations should have rounded bell shapes, but they do not. By measuring one of the harps and performing detailed model calculations, the astrophysicists were able to show that streaming must be the most important transport process of cosmic rays.

“The particles "pluck" the strings and stimulate the magnetic fields to oscillate, which in turn hold the particles together to form a streaming fluid,” explains Torsten Enßlin from the MPA, the initiator of the study.

With this illuminating Advent insight, the decades-old mystery of the transport of cosmic ray particles has been solved. Contrary to the previous assumption of diffusing particles, it turns out that they mainly stream.

Wissenschaftliche Ansprechpartner:

Timon Thomas, +49 331 7499 531,,
Christoph Pfrommer, +49 331 7499 513,,
Torsten Enßlin, +49 89 30000 2243


1. Probing Cosmic Ray Transport with Radio Synchrotron Harps in the Galactic Center. Timon Thomas, Christoph Pfrommer, and Torsten Enßlin, preprint:
2. Inflation of 430-parsec bipolar radio bubbles in the Galactic Centre by an energetic event. Heywood, I., Camilo, F., Cotton, W. D., et al. (2019), Nature, 573, 235

Dr. Janine Fohlmeister | idw - Informationsdienst Wissenschaft

More articles from Physics and Astronomy:

nachricht Electric solid propellant -- can it take the heat?
14.02.2020 | University of Illinois College of Engineering

nachricht Pitt study uncovers new electronic state of matter
14.02.2020 | University of Pittsburgh

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: Skyrmions like it hot: Spin structures are controllable even at high temperatures

Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices

The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...

Im Focus: Making the internet more energy efficient through systemic optimization

Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.

Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.

Im Focus: New synthesis methods enhance 3D chemical space for drug discovery

After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.

"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.

Im Focus: Quantum fluctuations sustain the record superconductor

Superconductivity approaching room temperature may be possible in hydrogen-rich compounds at much lower pressures than previously expected

Reaching room-temperature superconductivity is one of the biggest dreams in physics. Its discovery would bring a technological revolution by providing...

Im Focus: New coronavirus module in SORMAS

HZI-developed app for disease control is expanded to stop the spread of the pathogen

At the end of December 2019, the first cases of pneumonia caused by a novel coronavirus were reported from the Chinese city of Wuhan. Since then, infections...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

Latest News

Electric solid propellant -- can it take the heat?

14.02.2020 | Physics and Astronomy

Pitt study uncovers new electronic state of matter

14.02.2020 | Physics and Astronomy

Researchers observe quantum interferences in real-time using a new extreme ultra-violet light spectroscopy technique

14.02.2020 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>