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One antenna on each side of spacecraft, to see whole sky, i.e., as many GPS satellites at

(Two of these on spacecraft.). Serial communications. One of the two redundant antennae. Power. One antenna on each side of spacecraft, to see whole sky, i.e., as many GPS satellites at a time as possible. Receiver handles them both together. Absolute timestamp end-to-end test.

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One antenna on each side of spacecraft, to see whole sky, i.e., as many GPS satellites at

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  1. (Two of these on spacecraft.) Serial communications One of the two redundant antennae. Power One antenna on each side of spacecraft, to see whole sky, i.e., as many GPS satellites at a time as possible. Receiver handles them both together.

  2. Absolute timestamp end-to-end test Top phototube + scintillator To MVME interrupt To GPS Bottom phototube + scintillator Track of a single atmospheric muon

  3. LAT on spacecraft, above the floor. Scintillator paddles. Gamma-ray burst monitor got tested, too.

  4. So, we found & fixed a nasty clock bug, before launch. Clocks working great on orbit (better than a µs). Discovery of gamma-ray millisecond pulsars would not have been possible if the bug hadn't been found.

  5. Campaign to time 224 high Edot pulsars (best gamma-ray candidates, but unstable spin-down rate.) A&A 492, 293 (2008)

  6. Spin-down power Edot = 4p²Pdot/P3. newborn pulsars (The EGRET pulsars are here) “Recycled”, or millisecond pulsars Fermi so far: ~21 young radio pulsars ~15 new young pulsars (radio quiet?) ~ 9 MSPs ----------------- ~45 gamma pulsars in all Increasing as ~ Time In middle age, they become invisible, but can accrete a binary companion’s spin, to live again.

  7. Parkes (Australia) RXTE Jodrell Bank (England) Nançay (France)

  8. Bordeaux undergrads on field trip to Nançay, 29 June 2006

  9. The Pulsing g-ray Sky Pulses at 1/10th true rate

  10. PSR J2021+3651: first new Fermi pulsar PRELIMINARY Ap J submitted • No significant change in gamma peak location or shape with energy. • Excellent timing allows absolute phase comparisons: beam origins in the magnetosphere. • Re-analzyed Chandra continous clocking light curve (Hessels et al. 2004): • appears roughly aligned with gamma peaks

  11. Ap J accepted

  12. Article for Science in preparation

  13. 47 Tucanae – contains 23 millisecond pulsars. Detected as a (steady) GeV gamma-ray source. Adaptively smoothed counts maps (200 MeV - 10 GeV, s.n.r = 5) Zoom Location of LAT source relative to 47 Tucred circle: LAT 95% error radius contours: DSS2 stellar distribution (arbitrary units) Large area The source lies in an isolated sky region

  14. ·Les Nébuleuses à vent de Pulsar Une faible fraction de l'énergie rotationnelle d'un pulsar est convertie en émission pulsée observable, la majorité de l'énergie quittant la magnétosphère du pulsar sous forme d'un vent magnétisé. Ce vent peut interagir avec le milieu environnant et émettre du rayonnement synchrotron depuis le domaine radio jusqu'aux rayons X. L'interaction du vent avec le milieu interstellaire peut également produire des photons gamma du GeV au TeV par diffusion Compton inverse. Les observations radio et X nous ont permis d'établir un catalogue de 81 nébuleuses connues, dont 47 possèdent un pulsar associé détecté. Marianne Lemoine-Goumard et son étudiante Marie-Helène Grondin rédigent actuellement le premier article Fermi sur la Nébuleuse du Crabe et son pulsar, et ont présenté le premiers résultats sur deux autres systèmes notoires lors des conférences de cet hiver, Vela, et le Kookaburra. La recherche d'une émission spatialement étendue en gammas demande des analyses spécifiques qui sont en cours de développement. L'idée de base de cette analyse est de comparer, dans différentes bandes en énergie, le signal gamma provenant de la source avec une fonction morphologique (gaussienne ou disque suivant les cas de figure étudiés) convoluée à la « point spread function » (PSF) du LAT et de déduire ainsi les paramètres de la fonction de forme. Ce travail s'effectue dans le cadre d'une collaboration Bordeaux-Stanford pour laquelle une bourse nous a été accordée.

  15. The Crab Nebula

  16. The Crab Nebula : the standard candle of astronomy • G184.6-5.8 = PWN aka Crab Nebula • Distance = 2 kpc, age = 1240 yrs • No SNR shell detected • Powered by the Crab Pulsar (PSR B0531-21, dE/dt = 4.6.1038 erg/s)‏ • Detected at each wavelength • Morphology : • Radio : wisps • X-rays : torus and jet • High energy gamma-rays : pointlike source compared to EGRET and Cherenkov PSF High energy excess map of the Crab Nebula above 500 GeV (Albert et al, ApJ 674:1037, 2008)‏ Radio image of the Crab Nebula (VLA)‏ X-ray image of the Crab Nebula (Chandra)‏

  17. GeV-TeV connection • A connexion can be seen between Fermi and Cherenkov data.  firm identification of the Crab Nebula • The Crab Nebula can be used as a cross-calibration source (Bastieri et al, astro-ph/0504301, 2005)‏  reduce systematic uncertainty in energy scale and acceptance of the Cherenkov telescopes • A break in the Inverse Compton component may be estimated using Fermi and Cherenkov spectral results (MAGIC, …) with a relative error being less than 10%. Spectral energy distribution of the Crab Nebula • More photons are needed to determine the cut-off or break energy with precision.

  18. Spectral analysis of the Crab Pulsar • Analysis of the total phase interval • A cut-off can be estimated using Fermi data • Crab Pulsar spectral parameters: • Spectral Index ~ 1.9 • Cut-off energy ~ 5-7 GeV • Flux (E>100MeV) ~ (1.7 ± 0.3).10-6 cm-2.s-1 • Results are consistent with the EGRET data above 200 MeV Spectral energy distribution of the Crab Pulsar

  19. The Kookaburracomplex

  20. Fermi upper limits on Vela X Fermi contours H.E.S.S. contours Off-pulse On-pulse Off-pulse <0.3 GeV 0.3-3 GeV >3 GeV Vela pulsar phase histogram (2 cycles are shown)‏ On- (top) and off- (bottom) pulse phase images • No significant emission detected from the PWN in the off-pulse  an upper limit (95% C.L.) on the flux, assuming a pointlike source and a spectral shape in E-2: F(>100 MeV) < 4.5e-7 photons/cm/s is obtained with 75 days of Fermi data (35 days in pointed mode + 40 days in survey mode). (Abdo et al, astro-ph/0812.2960, 2008)‏

  21. 4. Evolution du groupe Pour que l’activité sur CTA ne se fasse pas au détriment de l’analyse des données de Fermi, nous envisageons un recrutement dans les 4 ans à venir. Compte-tenu de la présence dans le groupe d’un seul enseignant-chercheur (D. Dumora) et de l’arrivée récente de M. Lemoine-Goumard (CR2 CNRS en 2007), notre préférence va au recrutement d’un Maître de Conférences de l’Université de Bordeaux.

  22. Nous proposons d’apporter à CTA les contributions suivantes: • Analyses 3D de cascades électromagnétiques atmosphériques, avec application à l’étude des objets étendus, dont notamment les nébuleuses à vent de pulsar, et les vestiges de supernova. • Chronométrie de pulsars : datation absolue des évènements, au niveau de l’acquisition des données, ainsi que la suite de la campagne de mesures de rotation de pulsars gamma. • Etudes multi-longueurs d’onde des noyaux actifs de galaxies. • Etant donné l’ampleur de nos engagements actuels sur Fermi, notre groupe se propose de ne devenir actif dans CTA que vers la fin de 2010.

  23. Fermi LAT science objectives > 2000 AGNs blazars and radiogal = f(q,z) evolution z < 5 Sag A* Possibilities starburst galaxies galaxy clusters measure EBL* Un-IDs 10-50g-ray bursts/year GeV afterglow spectra to high energy *extragalactic background light. Probed via gg->e+e-. Dark Matter neutralino lines sub-halo clumps g-ray binaries Pulsar winds m-quasar jets Pulsars gammas from radio and X-ray pulsars blind searches for new Gemingas* pulsar wind nebulae * Name of the only radio-quiet gamma-ray pulsar known before launch Cosmic rays and clouds acceleration in Supernova remnants OB associations propagation (Milky Way, M31, LMC, SMC) Interstellar mass tracers in galaxies

  24. GLAST LAT Collaboration France IN2P3, CEA/Saclay Italy INFN, ASI, INAF Japan Hiroshima University ISAS/JAXA RIKEN Tokyo Institute of Technology Spain ICREA and Institut de Ciencies de l'Espai Sweden Royal Institute of Technology (KTH) Stockholm University United States Stanford University (SLAC and HEPL/Physics) University of California at Santa Cruz - Santa Cruz Institute for Particle Physics Goddard Space Flight Center Naval Research Laboratory Sonoma State University Ohio State University University of Washington Principal Investigator: Peter Michelson (Stanford University) ~270 Members (~90 Affiliated Scientists, 37 Postdocs, and 48 Graduate Students) construction managed by Stanford Linear Accelerator Center (SLAC), Stanford University

  25. GLAST en France Laboratoire Leprince-Ringuet Montpellier

  26. Fermi Gamma-ray Space Telescope GLAST renamed Fermi by NASA on August 26, 2008 http://fermi.gsfc.nasa.gov/ “ Enrico Fermi (1901-1954) was an Italian physicist who immigrated to the United States. He was the first to suggest a viable mechanism for astrophysical particle acceleration. This work is the foundation for our understanding of many types of sources to be studied by NASA’s Fermi Gamma-ray Space Telescope, formerly known as GLAST. ”

  27. The discovery of radio pulsars: 1967 • To study interstellar scintillation, they put short RC constants into their electronics • A big surprise. Neutron stars had been predicted, but they didn’t know. • Today: • >1800 known radio pulsars. • ~50 in X-rays • 6 optical • 6 in GeV gamma-rays before Fermi.

  28. Power Vela pulsar From Thompson via Kanbach Spectral Energy Distribution shows that most energy in X-rays and gammas, for all known gamma-ray pulsars.

  29. Look Bordeaux up on You Tube!! Search for « glastcenbg » (one word, no spaces) It’s 7 minutes long, quite fun, and in your choice of French or English. http://fr.youtube.com/watch?v=54IBWt-O8Co It’s also on Daily Motion… http://www.dailymotion.com/relevance/search/glastcenbg/video/x5lfbo_le-satellite-glast_tech

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