Gamma-Ray Astronomy in Bordeaux ===============================
In 1995 an Astroparticle Physics group was created at the Centre d’Etudes Nucleaires de Bordeaux-Gradignan (CENBG), a nuclear physics laboratory co-managed by the University of Bordeaux and by the Institut National de Physique Nucleaire et de Physique de Particules (IN2P3) of the French Centre National de Recherche Scientifique (CNRS). The CENBG has a staff of one hundred scientists and technical staff, performing research over a broad range of topics.
The group’s founder and initial leader was Jean Quebert. His initiative was supported by the laboratory director at that time, Philippe Quentin, and by the adjoint director of the IN2P3 for astroparticles of the time, Gerard Fontaine. The University created a "maitre de conferences" teaching position at the University, which was won by Denis Dumora. The IN2P3 allocated a "charge de recherche, 1ere classe" position, obtained by David Smith. A thesis student, Berrie Giebels, joined the enterprise.
The group contributed to the conception and execution of an innovative atmospheric Cherenkov telescope, CELESTE, located in the Pyrenees near the Spanish border [1,2]. CELESTE was the first detector sensitive to astrophysical gamma rays in the energy window beyond that of the EGRET detector on the Compton Gamma Ray Observatory (CGRO), but below that of imaging Cherenkov telescopes such as Whipple. From 1998 to dismantling in 2004, the CELESTE principal investigator was David A. Smith of the CENBG. Prior to his death in a car crash, Eric Pare lead CELESTE. Eric conceived and designed the most substantial part of CELESTE, and influenced STACEE’s design as well.A review of this class of detectors is in .
The photograph was taken at the top of the Themis tower just after the Padova workshop, "Towards a Major Atmospheric Cherenkov Detector-IV" that was held from September 11 to 13, 1995. From left to right are Patrick Fleury, Ken Ragan, Michael Punch, Rene Ong, David Smith, Eric Pare, and Corbin Covault. Ken, Rene, and Corbin were founders of STACEE. Michael has always stuck with imaging (Whipple, CAT, and now HESS and HESS-II).
The CELESTE measurement of the Crab nebula flux at 60 GeV was reported in , as was an upper limit on the Crab pulsar. The Crab pulsar limit remains the most constraining available. CELESTE further constrained the gamma ray flux from the EGRET pulsar PSR B1951+32, a constraint only recently improved with the MAGIC telescope [6,7]. The CELESTE pulsar results came principally from the CENBG group, which validated its analysis with the first optical Crab pulsar measurements published by a Cherenkov group . The CENBG established a close working relation with the astronomers at the Nancay radio telescope in France at this time .
CELESTE was an outstanding training ground, with former thesis students and postdocs now playing prominent roles in HESS, VERITAS, and other major international experiments. In addition to pulsar physics, CELESTE also constrained Super Symetric (SUSY) dark matter particle candidates , and made the first Cherenkov measurement of the flux from the blazar Mrk 501 below 100 GeV . The CENBG contribution was central to all these efforts. The Astroparticle group currently comprises 5 staff scientists, 1 postdoc, and 2 doctoral students.
1. B. Giebels: Nucl. Instr. Meth. \textbf412A 329-341 (1998)
2. CELESTE : An Atmospheric Cherenkov Telescope for High Energy Gamma Ray Astrophysics A490 (2002) 71-89 E. Paré et al.(pdf)
3. M. de Naurois et al: ApJ \textbf556, 343 (2002)
4. D. A. Smith: Review of the Solar Array Telescopes. In: \textitTowards a Network of Atmospheric Cherenkov Detectors VII — Palaiseau, ed by B. Degrange, G. Fontaine pp 67 - 79 (2005)
5. 2003, Emmanuel Durand doctoral thesis, U. of Bordeaux, Recherche de photons pulsés au-dessus de 30 GeV dans le Crabe et PSR B1951+32 avec le détecteur Cherenkov atmosphérique CELESTE.
6. Moya doctoral thesis http://www.gae.ucm.es/ marcos/TESIS/ and Symposium poster,
7. Magic ApJ on ’1951 (Albert et al 2006)
9. Indirect Search for Dark Matter in M31 with the CELESTE Experiment J. Lavalle, H. Manseri et al., A&A 450 (2006) 1-8, astro-ph/0601298.
10. Mrk 421, Mrk 501, and 1ES 1426+428 at 100 GeV with the CELESTE Cherenkov Telescope D.A. Smith, E. Brion et al, A&A accepted, July 2006, astro-ph/0608247