Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Contribute to Discovery of Gamma Rays from Starburst Galaxy

04.11.2009
Iowa State University astrophysicists contributed to the recent discovery that a galaxy quickly creating new stars is also a source of high energy gamma rays.

The discovery has just been published by the journal Nature. The study reports that researchers using the VERITAS array of four telescopes at the Fred Lawrence Whipple Observatory in Arizona have detected gamma rays of a trillion electron volts coming from the M 82 galaxy. The corresponding author of the article is Wystan Benbow of the Harvard-Smithsonian Center for Astrophysics and the Whipple Observatory.

Researchers discovered cosmic rays (mostly hydrogen nuclei) from space nearly a century ago and have developed theories about their origins in supernova remnants and star-forming galaxies, but hadn't found evidence to support those theories.

"This is a step toward solving a 100-year-old puzzle in cosmic ray physics," said Frank Krennrich, an Iowa State professor of physics and astronomy and a collaborator on the VERITAS project.

Gamma rays are high energy electromagnetic radiation. The rays discovered by the VERITAS researchers have a trillion times the energy of visible light. M 82 is a galaxy in the direction of the Ursa Major constellation that's 12 million light years from Earth. It is classified as a starburst galaxy. Such galaxies are colliding with other galaxies, causing shockwaves that compress gases and create stars at very high rates.

"What this shows is that there is a strong connection between a galaxy with high star formation, high gas density and the production of cosmic rays," Krennrich said.

But Krennrich said there's more work to be done to definitively trace gamma rays to cosmic rays in starburst galaxies.

Researchers believe more knowledge of gamma rays could help them explore distant regions of space, help them look for evidence of dark matter, determine how much electromagnetic radiation the universe has produced and answer questions about the formation of stars and galaxies.

Krennrich said one key to current gamma ray research is the VERITAS telescope system (that's the Very Energetic Radiation Imaging Telescope Array System). The $20 million instrument started operating in 2007 and is the world's most sensitive instrument for detecting gamma rays.

It's not easy to detect those rays. Even with their high energies, gamma rays can't penetrate the earth's atmosphere. When they hit the atmosphere, they create showers of electrons and positrons that create a blue light known as Cerenkov radiation. Those showers move very fast. And they're not very bright.

VERITAS looks for the rays with four reflector disks 12 meters across that look like satellite dishes. The reflectors are covered with mirrors that direct light into cameras attached to the front of each disk. Each camera is about 7 feet across and contains about 500 tube-shaped photon detectors or pixels.

All those detectors were built in a laboratory on the fourth floor of Iowa State's Zaffarano Physics Addition. The assembly took about $1 million and a lot of work by Iowa State post-doctoral researchers Martin Schroedter and Tomoyuki Nagai.

The telescope system is based on techniques Iowa State researchers Richard Lamb and David Carter-Lewis helped develop in the 1980s.

And now Krennrich says researchers are contemplating the next generation of gamma ray detection systems.

Krennrich said researchers are assembling a worldwide collaboration to plan and build a $300 million, 36-telescope array. The new instrument would be known as AGIS (the Advanced Gamma-ray Imaging System) and would be 10 times more sensitive than VERITAS.

Krennrich said Iowa State researchers are working on image-recognizing technology for the AGIS system that would help researchers by automatically separating gamma ray events from background events.

The new instrument, Krennrich said, might finally produce the data that establishes the origins of gamma rays and cosmic rays.

Frank Krennrich | Newswise Science News
Further information:
http://www.iastate.edu

More articles from Physics and Astronomy:

nachricht Water without windows: Capturing water vapor inside an electron microscope
13.12.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

nachricht Columbia engineers create artificial graphene in a nanofabricated semiconductor structure
13.12.2017 | Columbia University School of Engineering and Applied Science

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: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>