Cosmic Web of First Stars Unveiled
Scientists have discovered a new way to detect the first stars when the universe was in its infancy at a mere 1% of its present age.
The research will be unveiled for the first time by Professor Rennan Barkana from Tel Aviv University at a conference organized by Liverpool John Moores University and the University of Liverpool and sponsored by the Royal Astronomical Society and the Science and Technology Facilities Council, bringing together nearly a hundred astrophysicists from eighteen countries to discuss the latest results on the most distant and powerful explosions in the universe, gamma-ray bursts.
Gamma-ray bursts are brief, unpredictable bursts of radiation that occur anywhere on the sky and which are thought to be associated with the death of a massive star and the formation of a black hole in the early universe.
Until recently, astronomers believed that it was impossible to observe stars when the universe was so young and just coming out of its so-called dark age — a time when the universe was permeated by hydrogen gas and before any light sources such as stars had switched on. Now, however, scientists have used powerful computer models to show that an expected difference in the speed of gas and dark matter causes the first stars to clump together into a prominent cosmic web.
“The discovery of these web-like structures now makes it feasible for radio astronomers to detect the 21-cm wavelength light from the first stars when the universe was only 200 million years old and still emerging from its dark ages”, said Dr. Barkana.
Professor Carole Mundell, from LJMU’s Astrophysics Research Institute, who is the lead organizer of the conference said, “This result is very exciting because it opens a new window on an era that has always been considered challenging for observers.”
LJMU scientists from the Astrophysics Research Institute are at the forefront of gamma-ray research, with the robotic Liverpool Telescope on the Canary island of La Palma having a uniquely powerful capability to react rapidly to notifications from gamma-ray detector satellites — such as NASA’s Swift — and catch the optical counterpart and fading afterglow of the explosion.
Professor Carole Mundell said: “Since the launch of NASA’s Swift satellite in 2004, over 700 new gamma-ray bursts have been detected out to the edges of the observable universe. Delegates will present the state-of-the-art in our understanding of black holes and their environments. We have an exciting agenda covering topics such as the very first stars in the universe, the nature of space-time and the detection of exotic particles.”
Professor Rennan Barkana’s research results will be published on Nature online on Wednesday 20th June [http://dx.doi.org/10.1038/nature11177] and in an upcoming issue.
Professor Nigel Weatherill, Vice-Chancellor of Liverpool John Moores University, and Liverpool’s new Lord Mayor Councillor Sharon Sullivan welcomed the scientists to the conference on Monday morning at the Maritime Museum in the historic Albert docks.
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Professor Barkana’s paper will be published in Nature with the title “The signature of the first stars in atomic hydrogen at redshift 20.” The full list of authors is Eli Visbal (Harvard), Rennan Barkana (Te Aviv University), Anastasia Fialkov (Tel Aviv University), Dmitriy Tseliakhovich (Caltech) and Chris Hirata (Caltech).
More information, including images: http://wise-obs.tau.ac.il/~barkana/naturez20.html
The results will be presented at the “Gamma-Ray Bursts in the Era of Rapid Follow-up” conference, running from 18-22 June at Liverpool John Moores University.
Conference home page: http://www.astro.ljmu.ac.uk/grb2012/
The conference is being led by Professor Carole Mundell (LJMU). Professor Bing Zhang (University of Nevada) is the co-chair of the scientific organizing committee and Dr. Shiho Kobayashi (LJMU) chairs the local organizing committee.
Gamma-ray bursts were first detected in the late 1960’s by military satellites monitoring violations of the nuclear test ban treaty and their existence was classified for years until they were recognized as colossal explosions at astronomical distances rather than man-made nuclear explosions in the atmosphere. In a matter of seconds, a GRB releases as much energy as the Sun is expected to emit over a lifetime of about ten billion years.
The conference is sponsored by the Royal Astronomical Society, the Science and Technology Facilities Council and Liverpool John Moores University.
The Royal Astronomical Society (RAS, http://www.ras.org.uk), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3,500 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
