Interactions News Wire
#88-05
10 November 2005
http://www.interactions.org*******************************************************************
Source:
Pierre Auger Observatory
Content: Press Release
Date Issued: 10 November
2005
*******************************************************************
Media
contacts: Paul Mantsch, Fermilab,
mantsch@fnal.govRosa Pacheco, Pierre
Auger Observatory,
augercelebration@auger.org.arMore
information on Pierre Auger Cosmic Ray Observatory, including visual overview
and interview with Nobel Laureate James Cronin: http://www.auger.org/
Pierre Auger
Observatory Images: http://www.auger.org/observatory/2004.html
For
Immediate ReleasePierre Auger Observatory Celebrates Progress on
Detector Array and Presents First Science ResultsMALARGÜE, Argentina
-- Scientists of the Pierre Auger Observatory, a project to discover the origins
of rare and mysterious ultra-high energy cosmic rays, began a celebration today
(10 November) in Malargüe, Argentina, to mark the progress on installation of
the Observatory’s detectors on the Argentina Pampas, and the presentation of the
first physics results.
"These highest-energy cosmic rays are messengers
from the extreme universe. They represent a great opportunity for discoveries,"
said Nobel Prize winner James Cronin, of the University of Chicago, who
conceived the Auger experiment together with Alan Watson of the University of
Leeds (UK). Watson added: "How does nature create the conditions to accelerate a
tiny particle to such an energy? Tracking these ultrahigh-energy particles back
to their sources will answer that question."
The opening symposium
included presentations on the origins of the project, the construction, and the
first science results. Guided tours of the Observatory will be given on Friday,
11 November. Events conclude on Saturday, 12 November, with a science fair
featuring participants from local schools.
“It is a great pleasure for
the Atomic Energy Commission of Argentina to participate in the celebration of
the Pierre Auger Project in Malargüe,” said Dr. Cristina Combiaggio, Director of
Centro Atomico Constituyentes of CNEA (Comision Nacional de Energia Atomica).
“We are very proud of having been able to collaborate with the Project from the
very beginning, assuming its leadership in our country, and we commit ourselves
to continue providing support.”
The Observatory collaboration includes
more than 370 scientists and engineers from 60 institutions in 16 countries, and
the construction cost of approximately $50 million (US) has been shared by the
participating countries. The international funding agencies are listed
below.
Commenting on the experiment’s progress, the Chief Executive of
the UK's Particle Physics and Astronomy Research Council [PPARC], Prof. Keith
Mason, said: "The Pierre Auger Observatory is a remarkable example of
international collaboration, and I am particularly proud that the UK was
involved at its inception and that our scientists continue to play a key role in
this project."
Dr. Roberto Petronzio, President of Italy’s Istituto
Nazionale di Fisica Nucleare (INFN), said the Auger experiment “represents an
important scientific engagement for INFN, which participates with researchers in
eight different areas of focus. The collaboration is the widest in the field of
cosmic ray physics and is aimed at clarifying the origins of the most energetic
particles streaking across the universe. The Pierre Auger Observatory
represents, in addition, an important project for the scientific development of
Latin America."
The Pierre Auger Observatory is trying to solve the
mystery of the origins of extremely rare ultra-high-energy cosmic rays – charged
particles showering the earth at energies above 1019 electron volts, about 10
million times higher than the the energy of the world's highest-energy particle
accelerator, the Tevatron at Fermilab. To witness these extremely rare events,
the observatory is constructing an array of 1600 detectors spread over 3000
square kilometers in Argentina's Mendoza Province, just east of the Andes
Mountains. Each detector contains 3000 gallons of ultra-pure, de-ionized water.
These “Cerenkov detectors” discern the presence of charged particles by
measuring the Cerenkov radiation, or electromagnetic shock waves, produced when
the particles move through the water faster than the speed of light in the
water. The effect is analogous to shock waves generated in the atmosphere by
planes flying at supersonic speeds. Information from the detectors is
transmitted by solar-powered cellular phone technology.
The detector
array covers an area approximately the size of the state of Rhode Island in the
United States. Surrounding the array is a set of 24 telescopes which, on clear
moonless nights, observe the ultraviolet fluorescence produced as cosmic ray
shower particles travel through the atmosphere. While a northern hemisphere site
has not yet been funded, the collaboration is working to establish a northern
hemisphere partner of the southern observatory, likely to be based in
southeastern Colorado in the US. With observatories in both hemispheres, the
Auger collaboration will have the opportunity to view cosmic rays across the
entire universe, from every direction.
"Once more science stands at
the threshold of resolving a fundamental question that has so far eluded mankind
– the source of high energy cosmic rays,” said Prof. Mason. “And I look forward
with great interest to Auger's quest to unravel one of Nature's most intriguing
mysteries."
The first science results from the Auger Observatory include
a new cosmic ray spectrum at the highest energies; the results of anisotropy and
point source searches; and new limits on the photon content of the
primaries,
which could address several points within exotic theories of
cosmic ray origin. The significance of the results:
*
The Observatory charts a spectrum by measuring the observed cosmic rays as a
function of energy. As the energy of the cosmic rays increases, the experiment
is seeing fewer and fewer of them. Auger observes cosmic rays at energies as
high as any other experiment has ever seen, if not higher, examining this high
energy range for interesting phenomena -- which might or might not
exist.
* Cosmic rays generally are charged particles.
Lower-energy rays are greatly affected by galactic magnetic fields, taking
twisted and distorted paths to earth. High-energy rays, less affected by
magnetic fields, take a more direct path to earth. If experimenters see more
rays from one direction than from another (anisotropy), they can refine their
observations to include point source searches, tracking back fairly closely to a
point source or an object in the sky.
* Scientists want to
know the makeup of the primaries, the cosmic ray particles that initially strike
the earth's atmosphere, creating further collisions with air moleclues that
eventually produce a cascade of particles called an extensive air shower. Is the
primary a proton, an atomic nucleus, or a photon? Researchers have determined
experimentally that the makeup of primaries cannot exceed a specific fraction (a
limit) of photons, which will eventually affect their thinking on some exotic
theories of cosmic ray origins.
* These exotic theories
include hypothetical objects left over from the Big Bang, called topological
defects, such as "cosmic strings," "domain walls," and "monopoles." If these
hypothetical phenomena existed, and then collapsed, their collapses could
produce enough energy to create very high-energy cosmic rays. If so, then a
certain fraction of cosmic rays would consist of photons. So far, the data is
not extensive enough to prove or disprove any of these phenomena. But enlarging
the data set over time will help Auger scientists narrow down the many different
theories of cosmic ray origin.
The Pierre Auger Cosmic Ray Observatory is
named for French scientist Pierre Victor Auger (1899-1993), who in 1938 was the
first to observe the extensive air showers generated by the interaction of
very-high-energy cosmic rays with the earth’s atmosphere.
Fermilab, which
hosts the project management office for the Pierre Auger Observatory, is a U.S.
Department of Energy Office of Science national laboratory, operated under
contract by Universities Research Association, Inc. DOE and NSF have designated
URA as the US representative on the project’s international oversight board,
currently chaired by URA President Fred Bernthal.
Auger
Observatory Collaborating Institutions by
Country Argentina
Instituto Balseiro, Centro Atómico
Bariloche - Comisión Nacional de Energía Atómica y Universidad Nacional de
Cuyo
Instituto de Astronomía y Física del Espacio - CONICET
Instituto de
Física de La Plata - Universidad Nacional de la Plata y CONICET
Laboratorio
TANDAR - Comisión Nacional de Energía Atómica
Universidad Tecnologica
Nacional - Regionales Mendoza & San Rafael
Australia
University of
Adelaide
Bolivia
Universidad Catolica de Bolivia
Universidad Mayor
de San Andres
Brazil
CBPF-Centro Brasileiro de Pesquisas
Fisicas
Universidade Estadual de Feira de Santana - Bahia
Universidade
Estadual do Sudoeste da Bahia
Universidade Federal da Bahia
Universidade
Federal do Rio de Janeiro
Universidade Federal Fluminense
Universidade de
Sao Paulo
Universidade Estadual de Campinas
Czech
Republic
Institute of Physics of the Academy of Sciences of the Czech
Republic
Institute of Particle and Nuclear Physics, Charles University
Prague
France
Institut de Physique Nucléaire,Orsay, and
IN2P3-CNRS
Laboratoire de l'Accélérateur Linéaire,Orsay, and
IN2P3-CNRS
Laboratoire AstroParticule et Cosmologie du Collège de France, and
IN2P3-CNRS
Laboratoire de Physique Nucléaire et de Hautes Energies,
Université Paris 6, and IN2P3-CNRS
Germany
Forschungszentrum
Karlsruhe-Institut für Kernphysik
Forschungszentrum Karlsruhe-Institut für
Prozessdatenveratbeitung und Elektronik
Max Planck-Institut für
Radioastronomie and Universität Bonn associated by Forschungszentrum Karlsruhe
Institut für Kernphysik
Rheinisch-Westfälische Technische Hochschule
Aachen
Universität Karlsruhe
Universität Siegen
Bergische Universität
Wuppertal
Italy
Dipartimento di Fisica
dell'Università and INFN, L'Aquila
Dipartimento di Fisica dell'Università and
Sezione INFN, Lecce
Dipartimento di Fisica dell'Università and Sezione INFN,
Milano
Dipartimento di Fisica dell'Università and Sezione INFN,
Napoli
Dipartimento di Fisica dell'Università di Roma “Tor Vergata” and
Sezione INFN Roma II
Dipartimento di Fisica Sperimentale dell'Università and
Sezione INFN, Torino
Istituto di Fisica dello Spazio Interplanetario (INAF),
Dipartimento di Fisica Generale dell'Università and Sezione INFN,
Torino
Sezione INFN di Catania & Dipartimento di Fisica e Astronomia
dell'Università, Catania
INFN, Laboratori Nazionali del Gran
Sasso
Mexico
Benemérita Universidad Autónoma de Puebla
Centro de
Investigacion y de Estudios Avanzados del IPN
Universidad Michoacana de San
Nicolás de Hidalgo
Universidad Nacional Autónoma de
México
Netherlands
Stichting Astronomisch Onderzoek in Nederland
(ASTRON), Dwingeloo
Institute for Mathematics, Astrophysics and Particle
Physics (IMAPP), Radboud Universiteit, Nijmegen
Kernfysisch Verneller
Instituut (KVI), Rijksuniversiteit Groningen, Groningen
Nationaal Instituut
voor Kernfysica en Hoge Energie Fysica (NIKHEF),
Nijmegen
Poland
Department of Experimental Physics, University of
Lodz
Institute of Nuclear Physics, Krakow
Slovenia
Nova Gorica
Polytechnic
Spain
Departamento de Fisica de Particulas,
Universidad de Santiago de Compostela
Universidad Complutense de
Madrid
Centro de Supercomputacíon de Galicia
Universidad de Alcalá de
Henares
United Kingdom
Oxford University
University of
Leeds
USA
Case Western Reserve
University
Clemson University
Colorado State University
Columbia
University
Fermilab National Accelerator Laboratory / Argonne National
Laboratory
Louisiana State University/Southern University
Michigan
Technological University
Northeastern University
Ohio State
University
Pennsylvania State University
University of California, Los
Angeles
University of Chicago
University of Colorado
University of
Minnesota
University of Nebraska
University of New Mexico
University of
Utah
Auger Observatory Funding Agencies by
CountryUNESCO
Argentina
La Provincia de
Mendoza
Comision Nacional de Energía Atómica
Fundacion
Antorchas
Australia
The Australian Research
Council
Brazil
Fundacao de Amparo a Pesquisa do Estado de Sao Paulo
(FAPESP)
Conselho Nacional de Desenvolvimento Cientifico e Tecnologico
(CNPq)
Financiadora de Estudos e Projetos do Ministerio dA Ciencia e
Tecnologia (FINEP/MCT)
Czech Republic
Ministry of Education, Youth and
Sports of the Czech Republic
France
Centre National de la Recherche
Scientifique (CNRS)
Département Sciences de l'Univers
(SDU-INSU/CNRS)
Département Physique Nucléaire et Corpusculaire
(PNC-IN2P3/CNRS)
Conseil Régional
Ile-de-France
Germany
Helmholtz-Gemeinschaft Deutscher
Forschungszentren
Bundesministerium für Bildung und Forschung (BMBF),
Germany
Deutsche Forschungsgemeinschaft DFG
Finanzministerium
Baden-Württemberg
Ministerium für Wissenschaft und Forschung, Nordrhein
Westfalen
Italy
Istituto Nazionale di Fisica Nucleare
(INFN)
Ministero dell'Istruzione, dell'Università e della Ricerca
(MIUR)
Mexico
Consejo Nacional de Ciencia y
Tecnología
Netherlands
Ministerie van Onderwijs, Cultuur en
Wetenschap
Stichting voor Fundamenteel Onderzoek der Materie
(FOM)
Nederlandse Organisatie voor Wetenschappelijk Onderzoek
(NWO)
Poland
Ministry of Science and Information Society
Technologies
Slovenia
Slovenian Research Agency
Ministry for Higher
Education, Science, and Technology
Spain
Ministerio de Educacíon y
Ciencia
Xunta de Galicia
FEDER funds
Consejería de Educacíon de la
Comunidad de Castilla La Mancha
United Kingdom
Particle Physics and
Astronomy Research Council
United States
Department of
Energy
National Science Foundation
The Grainger Foundation