The gamma rays observed by the team have energies more than a trillion times higher than the energy of visible light and are the highest-energy photons ever detected from a galaxy undergoing large amounts of star formation.
The discovery, made from data taken over a two-year-long observing campaign by the VERITAS collaboration of more than 100 scientists from 22 different institutions in the United States, Ireland, United Kingdom, and Canada, appears in the Nov. 1 advance online edition of the scientific journal Nature.
VERITAS (Very Energetic Radiation Imaging Telescope Array System) is a gamma ray observatory located at the Fred Lawrence Whipple Observatory near Amado, Ariz.
The finding provides “strong evidence” that exploding stars are the origin of cosmic rays, according to Jamie Holder, assistant professor of physics and astronomy at the University of Delaware and deputy spokesperson for the VERITAS collaboration.
Produced in violent processes in our own galaxy and beyond, cosmic rays are actually energetic particles that continually bombard Earth's atmosphere. They are important, Holder says, because they make up a large fraction of the energy budget of our galaxy, The Milky Way. The amount of energy in cosmic rays is comparable to the energy contained in both starlight, and in Galactic magnetic fields, Holder notes.
“Although cosmic rays were first detected 100 years ago, their origins have been a mystery,” says Holder. “One idea has been that they are produced by supernova explosions, but there was never any direct proof until now. This gamma ray measurement by VERITAS looks at a galaxy different from our own where there are 30 times as many supernovae. The fact that we see gamma rays indicates that there are many more cosmic rays being produced by these supernovae.”
In the active starburst region at the Cigar Galaxy's center, stars are being formed at a rate approximately ten times more rapidly than in “normal” galaxies like our Milky Way, Holder says.
The cosmic rays produced in the formation, life, and death of the massive stars in this region eventually produce diffuse gamma-ray emission via their interactions with interstellar gas and radiation.
Holder and former postdoctoral researcher Ester Aliu and doctoral student Dana Boltuch were involved in the study from UD.
Holder scheduled all of the observations as chair of the team's observing time allocation committee, and he and Aliu ran the array of telescopes based in southern Arizona to collect a significant portion of the 137 hours of data collected for the study. Holder provided a critical secondary analysis with an independent analysis package to confirm the result.
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.
Article by Tracey Bryant
Tracey Bryant | EurekAlert!
New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center
Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research