This image shows the afterglow of GRB 090423 (red source in the centre) and was created from images taken in the z, Y and J filters at Gemini-South and VLT (credit: A. J. Levan).
Astronomers explore 'last blank space' on map of the Universe
At 13 billion light years away, GRB 090423 sets new record for the most distant known object in the Universe
Issued on 29 October 2009
The most distant object ever discovered is described in this week's edition of the science journal Nature.
Two international teams of astronomers report their observations of a gamma-ray burst from a star that died when the Universe was 630 million years old, or less than 5 percent of its present age.
Dubbed GRB 090423, the record-breaker is an example of the brightest and most violent explosions known to exist. The explosion is thought to accompany the catastrophic death of a very massive star as it ended its life, and is triggered by the centre of the star collapsing to form a black hole.
"This observation allows us to begin exploring the last blank space on our map of the Universe", said Professor Nial Tanvir of the University of Leicester, who led one of the teams.
Although the gamma-ray burst itself occurred about 630 million years after the Big Bang, it is so far away (about 13.1 billion light years) that the light from the explosion only arrived at the Earth in April of this year. "It is tremendously exciting to be looking back in time to an era when the first stars were just switching on", commented team member Dr Andrew Levan of the University of Warwick.
Much of this light was in the form of very high energy gamma-ray radiation, which triggered the detectors on a NASA satellite called Swift. Following up on the automatic announcement from Swift several of the world's largest telescopes turned to the region of the sky within the next minutes and hours and located the faint, fading afterglow of the GRB. Detailed analysis revealed that the afterglow was seen only in infrared light and not in the normal optical. This was the clue that the burst came from very great distance.
Beyond the mere breaking of a record, the age of the newly detected object opens a window into a cosmological era that has not previously been accessible to observation. The cosmic "Dark Ages" are thought to have ended about 800-900 million years after the Big Bang, when light from stars and galaxies re-ionized the previously neutral gas pervading the Universe. As more gamma-ray bursts are detected from these early times, it should be possible to trace the progress of this re-ionization, leading to the intergalactic medium we see today.
Gamma-ray bursts are the Universe's most luminous explosions. Most occur when massive stars run out of nuclear fuel. As their cores collapse into a black hole or neutron star, gas jets -- driven by processes not fully understood -- punch through the star and blast into space. There, they strike gas previously shed by the star and heat it, which generates short-lived afterglows in other wavelengths.
The previous record holder was a burst with a redshift of 6.7, which places it 180 million light-years closer than GRB 090423.
The UK researchers are supported by the Science and Technology Facilities Council (STFC) which also funds the UK contribution to Swift, subscriptions to ESO and Gemini and owns the UK Infrared Telescope (UKIRT). Key parts of the instrumentation on Swift were built at the University of Leicester and University College London's Mullard Space Science Laboratory. Leicester also houses the UK Swift Science Data Centre which provided the most accurate X-ray location for GRB090423
NOTES TO EDITORS:
More information at:
Prof Nial Tanvir, University of Leicester, UK
Dr Andrew Levan, University of Warwick, UK
Prof Derek Fox, Penn State University, USA
phone: +1 814 863 4989
Prof. Ralph Wijers, University of Amsterdam, NL
The full listing of authors and their affiliations for this paper is as follows:
N. R. Tanvir1, D. B. Fox2, A. J. Levan3, E. Berger4, K. Wiersema1, J. P. U. Fynbo5, A. Cucchiara2, T. Krühler6,7, N. Gehrels8, J. S. Bloom9, J. Greiner6, P. Evans1, E. Rol10, F. Olivares6, J. Hjorth5, P. Jakobsson11, J. Farihi1, R. Willingale1, R. L. C. Starling1, S. B. Cenko9, D. Perley9, J. R. Maund5, J. Duke1, R. A. M. J. Wijers10, A. J. Adamson12, A. Allan13, M. N. Bremer14, D. N. Burrows2, A. J. Castro-Tirado15, B. Cavanagh12, A. de Ugarte Postigo16, M. A. Dopita17, T. A. Fatkhullin18, A. S. Fruchter19, R. J. Foley4,20, J. Gorosabel15, J. Kennea2, T. Kerr12, S. Klose21, H. A. Krimm22,23, V. N. Komarova18, S. R. Kulkarni24, A. S. Moskvitin18, C. G. Mundell25, T. Naylor13, K. Page1, B. E. Penprase26, M. Perri27, P. Podsiadlowski28, K. Roth29, R. E. Rutledge30, T. Sakamoto22, P. Schady31, B. P. Schmidt17, A. M. Soderberg4, J. Sollerman5,32, A. W. Stephens29, G. Stratta27, T. N. Ukwatta8,33, D. Watson5, E. Westra4, T. Wold12, C. Wolf28
1Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, UK
2Department of Astronomy & Astrophysics, Pennsylvania State University, University Park, PA 16802, USA
3Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
4Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
5Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark
6Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße 1, 85740 Garching, Germany
7Universe Cluster, Technische Universitat München, Boltzmannstrasse 2, 85748 Garching, Germany
8NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
9Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA
10Astronomical Institute “Anton Pannekoek”, University of Amsterdam, PO Box 94249, 1090 GE Amsterdam , The Netherlands
11Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavík, Iceland
12Joint Astronomy Centre, 660 N. A'ohoku Place, University Park, Hilo, Hawaii 96720, USA
13School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
14H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
15Instituto de Astrofísica de Andalucía del Consejo Superior de Investigaciones Científicas (IAA-CSIC), PO Box 03004, E-18080 Granada, Spain
16European Southern Observatory, Casilla 19001, Santiago, Chile
17Research School of Astronomy & Astrophysics, The Australian National University, Cotter Road, Weston Creek ACT 2611, Australia
18Special Astrophysical Observatory, Nizhnij Arkhyz, Karachai-Cirkassian Republic, 369167 Russia
19Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD21218, USA
21Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg, Germany
22CRESST and NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
23Universities Space Research Association, 10211 Wincopin Circle, Suite 500, Columbia, MD 21044, USA.
24Department of Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125, USA
25Astrophysics Research Institute, Liverpool John Moores University, Birkenhead CH41 1LD, UK
26Department of Physics and Astronomy, Pomona College, Claremont, CA 91711, USA
27ASI Science Data Center, via Galileo Galilei, 00044 Frascati, Italy
28Department of Physics, Oxford University, Keble Road, Oxford, OX1 3RH, UK
29Gemini Observatory, Hilo, HI 96720, USA
30Physics Department, McGill University, 3600 rue University, Montreal, QC H3A 2T8, Canada
31The UCL Mullard Space Science Laboratory, Holmbury St Mart, Dorking, Surrey, RH5 6NT, UK
32The Oskar Klein Centre, Department of Astronomy, Stockholm University, 106 91 Stockholm, Sweden
33The George Washington University, Washington, DC. 20052, USA
The following funding acknowledgements from the authors appear at the end of the paper:
Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and SECYT (Argentina). Based on observations made with ESO Telescopes at the La Silla or Paranal Observatories by G. Carraro, L. Schmidtobreick, G. Marconi, J. Smoker, V. Ivanov, E. Mason and M. Huertas-Company. The UKIRT is operated by the Joint Astronomy Centre on behalf of the UK Science and Technology Facilities Council.