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FERMI Gamma-ray Space Telescope (GLAST) Overview and status of FERMI Observatory

FERMI Gamma-ray Space Telescope (GLAST) Overview and status of FERMI Observatory N.Giglietto (INFN and Politecnico of Bari) on behalf of the Glast Collaboration. Launch!. Launch from Cape Canaveral Air Station 11 June 2008 at 12:05PM EDT (18:05PM Rome)

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FERMI Gamma-ray Space Telescope (GLAST) Overview and status of FERMI Observatory

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  1. FERMI Gamma-ray Space Telescope (GLAST) Overview and status of FERMI Observatory N.Giglietto (INFN and Politecnico of Bari) on behalf of the Glast Collaboration

  2. Launch! • Launch from Cape Canaveral Air Station 11 June 2008 at 12:05PM EDT (18:05PM Rome) • Circular orbit, 565 km altitude (96 min period), 25.6 deg inclination. • Communications: • Science data link via TDRSS Ku-band, average data rate 1.2 Mbps. • S-band via TDRSS and ground stations

  3. 25.6 Degree Orbit Fermi satellite position just now! SAA Circular orbit, 565 km altitude (96 min period), 25.6 degrees inclination http://observatory.tamu.edu:8080/Trakker(track the satellite) http://www.nasa.gov/mission_pages/GLAST/news/glast_online.html(look at Fermi in the sky from your place)

  4. Fermi LAT Collaboration • France • IN2P3, CEA/Saclay • Italy • INFN, ASI, INAF • Japan • Hiroshima University • ISAS/JAXA • RIKEN • Tokyo Institute of Technology • 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)

  5. Fermi Key Features • Two instruments on board: • LAT: • high energy (20 MeV – >300 GeV) • GBM: • low energy (8 keV – 30 MeV) • Huge field of view • LAT: 20% of the sky at any instant; in sky survey mode, expose all parts of sky for ~30 minutes every 3 hours. GBM: whole unocculted sky at any time. • Huge energy range, including largely unexplored band 10 GeV - 100 GeV • Large leap in all key capabilities, transforming our knowledge of the gamma-ray universe. Great discovery potential. Large Area Telescope (LAT) Spacecraft Partner: General Dynamics GLAST Burst Monitor (GBM)

  6. The Fermi Observatory LAT GBM Sodium Iodide Detector GBM Bismuth Germanate Detector

  7. e– e+ FERMI LAT: A Telescope Without Lenses • Precision Si-strip Tracker (TKR) 70 m2 of silicon detectors arranged in 36 planes. 880,000 channels.Only 600W power consuption! • HodoscopicCsI Calorimeter(CAL) 1536 CsI(Tl) crystals in 8 layers, total mass 1.5 tons. • Segmented Anticoincidence Detector (ACD) 89 plastic scintillator tiles. • Electronics System Includes flexible hardware trigger and onboard computing. Tracker ACD [surrounds 4x4 array of TKR towers] Calorimeter Systems work together to identify and measure the flux of cosmic gamma rays with energy 20 MeV - >300 GeV.

  8. Pair-Conversion Telescope anticoincidence shield conversion foil particle tracking detectors e– • calorimeter • (energy measurement) e+ LAT Experimental Technique • Instrument must measure the direction, energy and arrival time of gamma rays over a large energy range (~20 MeV to > 300 GeV) • Technique: Pair Conversion Telescope • Concept: • Photon interactions in GLAST energy range dominated by pair conversion • Determine the photon direction • Clear signature for background rejection • Basic requirements • Must detect gamma-rays with high efficiency • Must be able to reject much larger flux (104:1) of cosmic ray backgrounds • Must have a large acceptance (Field Of View) • Must have good energy resolution over wide range of incident photon energies • Some Definitions: • Effective Area (Aeff): • (Total Geometric Acceptance) • (conversion probability) • (all detector and reconstruction efficiencies). • Real rate of detecting a signal is (flux) • Aeff • Point Spread Function (PSF): • Angular resolution of instrument, after all detector and reconstruction algorithm effects. The 2-dimensional 68% containment is the equivalent of ~1.5 (1-dimensional error) if purely Gaussian response. The non-Gaussian tail is characterized by the 95% containment, which would be 1.6 times the 68% containment for a perfect Gaussian response.

  9. GLAST/LAT performance Energy Resolution: ~10% (~5% off-axis) PSF (68%) at 100 MeV ~ 5o PSF (68%) at 10 GeV ~ 0.1o Field Of View: 2.4 sr Point Source sens. (>100 MeV): 3x10-9 cm-2 s-1

  10. FERMI MISSION ELEMENTS Large Area Telescope & GBM m • sec GPS • - • Telemetry 1 kbps GLAST Spacecraft • TDRSS SN S & Ku DELTA 7920H • • S - - • GN • LAT Instrument Science Operations Center White Sands Schedules Mission Operations Center (MOC) GLAST Science Support Center HEASARC Schedules GRB Coordinates Network GBM Instrument Operations Center Alerts Data, Command Loads

  11. Timeline after launch • 12 - 14 June • routine communications established • Guidance, Navigation, and Control (GN&C) components powered on and functional. First transition from inertial pointed mode to sky survey mode. • 15-23 June • observing modes and patterns tested • science data return link established and tested • 24-25 June • INSTRUMENTS TURNED ON! • process completed much faster than expected, no significant problems encountered. • triggering and recording events. Rates close to expectation. Everything is functioning very well. • LAT data shipped to Instrument Science Operation Center at SLAC and routinely processed. GBM data shipped to the GBM Instrument Operations Center in Huntsville and routinely processed. • 26-28 June • Continued detailed instrument studies. • Burst alert path tested.

  12. Observatory Status in July • All systems checked out and functioning very well! • GPS information (position, time) spot-on, better than requirements by large factors. • Both instruments (LAT&GBM) turned on and operational. • well into period of detailed instrument engineering studies, tuning and on-orbit calibrations. Essential steps prior to science observations. • instrument team members worldwide happily examining the engineering data. • backgrounds appear to be close to expectation and very manageable. • GREAT cooperation across all the instrument elements, functioning as an integrated team. • Updates will be posted http://blogs.nasa.gov/cm/blog/GLAST

  13. Engineering Data Single Event Pictures Single event display, showing the detector information in graphical form, from a few of the many events that passed the nominal gamma-ray selection criteria in the early mission engineering data. The green crosses show the detected positions of the charged particles, the blue lines show the reconstructed track trajectories, and the yellow line shows the candidate gamma-ray estimated direction.  The red crosses show the detected energy depositions in the calorimeter.  The anticoincidence detector shows no incoming charged particles in these events.

  14. Engineering Data Single Event Pictures

  15. Engineering Data Single Event Pictures

  16. Year 1 Science Operations Timeline Overview Start Year 1 Science Ops Start Year 2 Science Ops “first light” whole sky LAT, GBM turn-on check out Observatory renaming spacecraft turn-on checkout sky survey + ~weekly GRB repoints + extraordinary TOOs pointed + sky survey tuning week week week week month 12 m o n t h s LAUNCH L+60 days 2nd GLAST Symposium initial tuning/calibrations in-depth instrument studies 2months of calibrations&tuning Release Flaring and Monitored Source Info GBM and LAT GRB Alerts continuous release of new photon data GI Cycle 1 Funds Release GI Cycle 2 Proposals Fellows Year 1 Start LAT Year 1 photon data release PLUS LAT Year 1 Catalog and Diffuse Model LAT 6-month high-confidence source release, GSSC science tools advance release

  17. the LAT science objectives > 100 MeV, 1 yr sensitivity x25 localization x10 field x4 observing efficiency x2 deadtime x10-3 > 2000 AGN blazars and radiogalaxies evolution z ≤ 5 (Sag A*) > 50 pulsars magnetosphere physics pulsar wind nebulae Simulated sky! γ-ray binaries pulsar winds µ-qso jets > 50 GRB /year GeV afterglow Solar Physics: Solar flares, IC emission, Moon emission dark matter neutralino line and cont. distr. searches cosmic rays & clouds acceleration in supernova remnants OB associations, SNOBs propagation (MWay, M31, LMC, SMC) dark gas & ISM mass tracers hopes starburst galaxies galaxy clusters new source classes

  18. FERMI Operating Modes Sensitivity • Primary observing mode is Sky Survey • Full sky every 2 orbits (3 hours) • Uniform exposure, with each regionviewed for ~30 minutes every 2 orbits • Best serves majority of science, facilitates multiwavelength observation planning • Exposure intervals commensurate with typical instrument integration times for sources • EGRET sensitivity reached in ~days • Pointed observations when appropriate with automatic earth avoidance selectable. Target of Opportunity pointing. • Autonomous repoints for onboard GRB detections in any mode. 100s 1 orbit rms/mean=14%, dominated by SAA effects exposure [cm2s]

  19. Energy Calibration with Ions Proton MIP Ion peaks are used for calibrations • Heavy ions probe the higher energy ranges • Peak positions stable to < 1% over days elapsed Non-Interacting Heavy Ion C N O Carbon peak vs time Fe

  20. First results: summary • perfect spatial and temporal alignments (Vela) • Vela phase diagram after few observation days • Pulsars: about 15 already observed • Moon emission detected after 4 days • Sun quiet emission • Several AGNs seen (some are flaring) • LMC emission and extension • GRBs

  21. The LAT’s First Public Volley: 3C454.3 ATel

  22. First results: Vela – early returns Soup to nuts: everything works! timing background rejection alignment EGRET on-pulse off-pulse • precise ephemerides of many pulsars provided by Parkes, Jodrell Bank, Green bank, Nançay, Arecibo, Hartbeesthoek, Urumqi, RXTE, XMM... • good timing of the EGRET pulsars • selecting on-pulse shows point source • evaluate PSF • alignment of LAT to sky

  23. First Results: AllSky map (2months, 1M gammas) 1510-089 geminga CTA1 Cygnus region Crab 3C454.3 Vela

  24. Position Reconstruction Verification • good localization of the EGRET pulsars: ~ 35 mas • 4-day data in slewing (survey) mode Vela Crab Geminga

  25. First results: Moon emission Moon emission Crab transit in fov

  26. Rates ~2kHz trigger rate ~5 Hz source photon rate 26 ms deadtime

  27. Data Release plan and operations • First Year observations - Sky Survey • After initial on-orbit checkout (60 days), the first year of observations will be a sky survey. • Repoints for bright bursts and burst alerts will be enabled • Extraordinary ToOs will be supported. • First year data will be used for detailed instrument characterization and key projects (catalog, background models etc). • First Year Data release • All GBM data • Information on all LAT detected GRB (flux, spectra, location) • High level LAT data (time resolved flux/spectra) on ~20 selected sources and on all sources which flare above 2x10-6, continued until the source flux drops below 2x10-7 (rate ~ 1-4 such objects per month). • The LAT team will produce a preliminary source catalog after ~6 months on a best effort basis • Subsequent years: Observing plan driven by guest observer proposal selections by peer review. Default is sky survey mode. • All data publicly released within 72 hours through the Science Support Center (GSSC). • See http://glast.gsfc.nasa.gov/ssc/data/policy/ for more details

  28. LAT First Year Source Monitoring List The LAT team will release flux/spectra as a function of time for all sources in the list. This data will be provided for daily and weekly integrations for all sources. In addition, flux/spectra will be released for any source which flares above 2e-6 ph/cm^2/s until the flux drops below 2e-7 ph/cm^2/s (1-4/month) This will be a “quicklook” analysis, priority is to get the results out as quickly as possible. Tables will be updated as analysis and calibrations improve.

  29. Conclusions • LAT Launch and Turn On have been huge successes!! • Commissioning nearly complete: no real surprises yet. LAT is stable! • Initial post-launch calibrations complete • Enter survey mode after L+60 • Will already have surpassed the EGRET dataset • First year data will be used for detailed instrument characterization and key projects (catalog, background models etc). • First Year Data release • Start releasing selected light curves in end August • preliminary source catalog after ~6 months on a best effort basis • GLAST renamed as Fermi in “First Light” ceremony on Aug 26 • Lots of excitement to come!

  30. Extra slides

  31. Active Galactic Nuclei AGN signature • vast amounts of energy (1049 erg/s) from a very compact central volume • large luminosity fluctuations in fractions of a day • energetic (multi-TeV), highly-collimated, relativistic particle jets Prevailing idea:accretion onto super-massive black holes (106 - 1010 solar masses) AGN physics to-do list • catalogue AGN classes with a large data sample (~>3000 new AGNs) • identify contributions from leptonic (SSC/ESC) and/or hadronic (0 decay) emissions in the spectra – multiwavelength campaigns • resolve diffuse background and study redshift dependence of cut-off to probe EBL • track flares ( ~ minutes)

  32. N.Giglietto- FARO Jan, 8th 2005 LAT studies EBL cutoff Probe history of star formation to z ~4 by determining spectral cutoff in AGN due to EBL

  33. N.Giglietto- FARO Jan, 8th 2005 AGN &EBL Studies Photons with E>10 GeV are attenuated by the diffuse field of UV-Optical-IR extragalactic background light (EBL) Opacity (Salamon & Stecker, 1998) only e-tof the original source flux reaches us EBL over cosmological distances is probed by gammas in the 10-100 GeV range. Important science for GLAST! In contrast, the TeV-IR attenuation results in a flux that may be limited to more local (or much brighter) sources. opaque A dominant factor in EBL models is the time of galaxy formation -- attenuation measurements can help distinguish models. No significant attenuation below ~10 GeV.

  34. locate SNR • resolve SNR shells at 10 level • measure SNR spectra GLAST will E (MeV) CR production and acceleration in SNR • SNR widely believed to be the source of CR proton acceleration after shell interaction with interstellar medium • 0 bump in the galactic spectrum detected by EGRET GLAST simulations showing SNR -Cygni spatially and spectrally resolved from the compact inner gamma-ray pulsar – a clear 0 decay signature from the shell would indicate SNR as a source of proton CR

  35. N.Giglietto- FARO Jan, 8th 2005 Pulsar physics with GLAST known gamma-ray pulsars direct pulsation search in the -ray band • high time resolution detect new gamma-ray pulsars (~250) precise test of polar cap vs outer gap emission models • large effective area 

  36. N.Giglietto- FARO Jan, 8th 2005 Road Map for Photons from Dark Matter Where Galactic Center Known Location Intensity Dependence Diffuse Character Extra Galactic Associated with AGN Point Like Character Type Line XXgg, gZ0 (Small Br, Line Spectra) Inclusive XX g + Anything (Large Br, Continuum Spectra) Particle Source SUSY X: c0 (LSP - many models parameter space large) LIMP X: Heavy nR (Signal to weak too be observed by GLAST) Focus on Galactic Center

  37. N.Giglietto- FARO Jan, 8th 2005 Set limits on relic mass, density and lifetime Diffuse emission from Relic decay Unresolved AGNs WIMPs Total GLAST EGRET

  38. N.Giglietto- FARO Jan, 8th 2005 GLAST WIMP Search Regions • Galactic center • Galactic satellites • Galactic halo • Extra-galactic

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