Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers find record-old cosmic explosion

11.01.2008
Oldest known short gamma ray burst occurred halfway back to Big Bang

Using the powerful one-two combo of NASA’s Swift satellite and the Gemini Observatory, astronomers from a number of institutions, including Johns Hopkins, have detected a mysterious type of cosmic explosion farther back in time than ever before.

The explosion, known as a short gamma-ray burst (GRB), took place 7.4 billion years ago, more than halfway back to the Big Bang.

"This discovery dramatically moves back the time at which we know short GRBs were exploding. The short burst is almost twice as far as the previous confirmed record holder," says John Graham, a graduate student in the Henry A. Rowland Department of Physics and Astronomy at The Johns Hopkins University. Graham is presenting his group’s discovery at the American Astronomical Society’s 2008 winter meeting this week in Austin, Texas.

GRBs are among the most powerful explosions in the universe, releasing enormous amounts of energy in the form of X-rays and gamma rays. Most bursts fall in one of two categories: long bursts and short bursts, depending on whether they last more or less than three seconds. Astronomers believe that long GRBs are triggered by the collapse and explosion of massive stars. In contrast, a variety of mechanisms has been proposed for short bursts. The most popular model says that most short GRBs occur when two neutron stars smash into each other and collapse into a black hole, ejecting energy in two counter-flowing beams.

The record-setting short burst is known as GRB 070714B, named because it was the second GRB detected on July 14, 2007. NASA’s Swift Gamma-Ray Burst Mission discovered the GRB in the constellation Taurus. Rapid follow-up observations with the 2-meter Liverpool Telescope and the 4-meter William Herschel Telescope found an optical afterglow in the same location as the burst, which allowed astronomers to identify the GRB’s host galaxy.

Next, Graham and his colleagues, Andrew Fruchter of the Space Telescope Science Institute and Andrew Levan of the University of Warwick in the United Kingdon, trained the 8-meter Gemini North Telescope in Hawaii on the galaxy. Analysis of a spectrum of the light from that galaxy indicated that it is 7.4 billion light-years away, meaning the explosion occurred 7.4 billion years ago.

"The fact that this short burst is so far away means this subclass has a broad range of distances, although they still tend to be closer on average than long GRBs," says Swift lead scientist Neil Gehrels of NASA’s Goddard Space Flight Center in Greenbelt, Md.

Gehrels adds that GRB 070714B’s energy was about 100 times higher than average for short bursts, more similar to the typical energy of a long GRB.

"It is unclear whether another mechanism is needed to explain this explosion, such as a neutron star-black hole merger," Gehrels said. "Or it could be that there are a wide range of energies for neutron star-neutron star mergers, but that seems unlikely."

Another possibility is that GRB 070714B concentrated its energy in two very narrow beams and that one of the beams happened to be aimed directly at Earth, making the burst seem more powerful than it really was. Researchers wonder if most short GRBs eject their energy in wider, less concentrated beams.

"We now have a good idea of the type of star that produces the brighter long bursts. But how short bursts are formed remains a mystery," Fruchter said.

Lisa DeNike | EurekAlert!
Further information:
http://www.jhu.edu

More articles from Physics and Astronomy:

nachricht Squeezing light at the nanoscale
17.06.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht The Fraunhofer IAF is a »Landmark in the Land of Ideas«
15.06.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

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: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

A sprinkle of platinum nanoparticles onto graphene makes brain probes more sensitive

15.06.2018 | Materials Sciences

100 % Organic Farming in Bhutan – a Realistic Target?

15.06.2018 | Ecology, The Environment and Conservation

Perovskite-silicon solar cell research collaboration hits 25.2% efficiency

15.06.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>