Pierre Auger Observatory

Previous Spokespersons

James MatthewsJames Matthews

Co-Spokesperson 2010-2013

James Matthews, Professor of Physics at Louisiana State University and at Southern University in Baton Rouge, Louisiana, USA, earned his Ph.D. at the University of Wisconsin - Madison in 1984. He was on the faculty of the University of Michigan from 1986 to 1997; then he moved to Louisiana as part of the Louisiana Board of Regents Joint Faculty Appointment Program.

He has worked on experimental searches for proton decay, TeV gamma rays at Haleakala, and on the CASA-MIA air shower experiment. He has been a part of the Auger Project since its inception in 1992, editing the Design Report in 1995. In Auger, he has worked on shower simulations, surface detector designs, construction of surface detectors, analysis of detector waveforms, and fluorescence detector calibration systems. He was chair of the Publications Committee from 2005 to 2010.


Giorgio MatthiaeGiorgio Matthiae

Spokesperson 2006-2010

Giorgio Matthiae received his Degree in Physics from the University of Rome in 1960. He was CERN fellow and staff member in the Experimental Physics Division of CERN. He became Professor of Physics at the University of Naples in 1980. Since 1985 he is Professor of Physics at the University of Roma II "Tor Vergata". In the period 1996-2002 he was Director of the Sezione INFN (Istituto Nazionale di Fisica Nucleare) of Roma II.

His principal activity has been experimental physics at high-energy accelerators. Amongst his scientific achievements are the measurements of proton-proton and proton-nucleus interactions at the CERN Proton Synchrotron (1964-1970) and the study of proton-proton elastic scattering and total cross section (1970-1975) at the CERN Intersecting Storage Rings (CERN-Rome group). In these experiments it was discovered that the total cross section increases with energy in the high-energy domain. Then he studied dimuon production in high-energy collisions (experiment NA3, 1975-1980). In the period 1980-1988 he was spokesman of experiment UA4 at the CERN SPS collider, which measured the proton-antiproton total cross section, elastic scattering and processes of diffraction dissociation. From 1988 to 1999, as leader of the Rome group involved in the DELPHI collaboration, he contributed to the construction of the calorimeters and to the analysis on the search of the Higgs particles, on b quark physics and on the measurement of the W mass.

In 1997 he joined the Auger project, acting as country representative of Italy in the collaboration. He has given important contributions to the design and construction of the fluorescence telescopes and is currently responsible for the cameras of the telescopes.


Paul SommersPaul Sommers

Co-Spokesperson 2006-2010

Paul Sommers is professor of physics at Penn State where he holds a joint appointment in the department of astronomy and astrophysics. He is the associate director of the Institute for Gravitation and the Cosmos.

Sommers got his PhD in physics at the University of Texas, Austin, in 1973 with a specialty in general relativity. His attention turned to cosmic ray physics in 1983 at the University of Utah. He has worked on the Auger Observatory since the inception of the project in 1992. He served as task leader for fluorescence detectors 1995-2001 and co-chair of the Auger Collaboration Board 2001-2006.


Johannes BluemerJohannes Blümer

Co-Spokesperson 2001-2003

Johannes Blümer had worked previously at the Universities of Dortmund (PhD in 1985) and Mainz and at CERN, where he was spokesperson of the NA48 experiment, which performed the first precicion measurement of direct CP Violation. He moved to Karlsruhe in 1999 following a dual appointment as Professor at Karlsruhe University and Director of the Institute for Nuclear Physics at Forschungszentrum Karlsruhe.

Blümer joined Auger during the 'good-will tour' of 1998 through Argentina. He helped to initiate astroparticle physics as a field of its own distinction. Blümer led the Auger North design efforts; he is also a member of the Auger Finance Board since the beginning.

Karlsruhe University and Forschungszentrum Karlsruhe merged in 2009 into the Karlsruhe Institute of Technology (KIT), where Blümer serves as spokesperson of the KIT Center Elementary Particle and Astroparticle Physics (KCETA), of the related Graduate School (KSETA) and of the Helmholtz Programme 'Matter and the Universe'.

Blümer continues to promote astroparticle physics worldwide and in particular in South America, notable in relations with the Instituto Tecnologias de Deteccion y Astroparticulas (ITEDA) and with the Universidad Nacional de San Martin (UNSAM), both in Buenos Aires.


Jim CroninJim Cronin (deceased 25. Aug. 2016)

Spokesperson Emeritus

James W. Cronin, professor of physics at the University of Chicago, received a Ph.D. in physics from the University of Chicago in 1955. He served as assistant physicist at Brookhaven National Laboratory from 1955 until 1958, when he accepted an appointment as assistant professor of physics at Princeton University. He became professor of physics at Princeton in 1964. In 1971, he returned to the University of Chicago as professor of physics. Dr. Cronin's many awards include the Nobel Prize, which he received in 1980 with physicist Val L. Fitch, for their discovery of charge conjugation/parity violation, the asymmetry in the behavior of matter and antimatter. Dr. Cronin was a member of the National Academy of Science and the American Academy of Arts and Science; he was a fellow of the American Physical Society.


Alan WatsonAlan Watson

Spokesperson Emeritus

Alan A. Watson, professor of physics at the University of Leeds in the United Kingdom. He accepted a lectureship in physics at Leeds in 1964, doing research on ultrahigh-energy cosmic rays as a member of the Haverah Park group. In 1976, he became director of the research program on extensive air showers of the Leeds University group at Haverah Park and, beginning in 1986, at the South Pole. Dr. Watson accepted an appointment as professor of physics at Leeds in 1984, and served as chairman of the Physics Department from 1989 to 1993. His 150 published papers, articles, and conference reports reflect his lifelong research interest in ultrahigh-energy cosmic rays, high-energy gamma rays, and high-energy astrophysics.