GLAST LAT Project DOE Mini-review 12 October 2004 S. Ritz 1 Introduction Introduction S. S. Ritz Ritz Technical and Technical and Production Status Production Status L. L. Klaisner Klaisner Instrument Science Instrument Science Operations Center Operations Center Plans Plans R. R. Cameron Cameron Project Status, Project Status, Cost and Schedule Cost and Schedule L. L. Klaisner Klaisner Gamma-ray Large Gamma-ray Large Area Space Area Space Telescope Telescope
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GLAST LAT Project DOE Mini-review 12 October 2004
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IntroductionIntroduction S. RitzS. Ritz
Technical andTechnical andProduction StatusProduction Status L. KlaisnerL. Klaisner
Instrument ScienceInstrument ScienceOperations Center Operations Center PlansPlans R. CameronR. Cameron
Project Status,Project Status,Cost and ScheduleCost and Schedule L. KlaisnerL. Klaisner
Gamma-ray Large Area Gamma-ray Large Area Space TelescopeSpace Telescope
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Why studyWhy study’s?’s?
Gamma rays carry a wealth of information:– rays do not interact much at their source: they offer a direct
view into Nature’s largest accelerators.– similarly, the Universe is mainly transparent to rays: can
probe cosmological volumes. Any opacity is energy-dependent.– conversely, rays readily interact
in detectors, with a clear signature.– rays are neutral: no complications
due to magnetic fields. Point directly back to sources, etc.
GLAST will have a very broad menu that includes:• Systems with supermassive black holes• Gamma-ray bursts (GRBs)• Pulsars• Solar physics• Origin of Cosmic Rays• Probing the era of galaxy formation• Discovery! Particle Dark Matter? Other relics from the Big Bang?
Testing Lorentz invariance. New source classes.
Huge increment in capabilities.Huge increment in capabilities.
GLAST ScienceGLAST Science
GLAST draws the interest of both the the High Energy Particle GLAST draws the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities. Physics and High Energy Astrophysics communities.
GLAST is the highest-ranked initiative in its category in the GLAST is the highest-ranked initiative in its category in the National Academy of Sciences 2000 Decadal Survey Report.National Academy of Sciences 2000 Decadal Survey Report.
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EGRET on GRO firmly established the field of high-energy gamma-ray astrophysics and demonstrated the importance and potential of this energy band.
GLAST is the next great step beyond EGRET, providing a huge leap in capabilities:
• Very large FOV (~20% of sky), factor 4 greater than EGRET
• Broadband (4 decades in energy, including unexplored region E > 10 GeV)
• Unprecedented PSF for gamma rays (factor > 3 better than EGRET for E>1 GeV)
• Large effective area (factor > 5 better than EGRET)
• Results in factor > 30-100 improvement in sensitivityResults in factor > 30-100 improvement in sensitivity
• Much smaller deadtime per event (25 microsec, factor >4,000 better than EGRET)
• No expendables long mission without degradation
GLAST LAT High Energy CapabilitiesGLAST LAT High Energy Capabilities
• Hodoscopic CsI Calorimeter(CAL)Hodoscopic CsI Calorimeter(CAL) Array of 1536 CsI(Tl) crystals in 8 layers. Measure the photon energy; image the shower.
• Segmented Anticoincidence Detector Segmented Anticoincidence Detector (ACD)(ACD) 89 plastic scintillator tiles. Reject background of charged cosmic rays; segmentation removes self-veto effects at high energy.
• Electronics System Electronics System Includes flexible, robust hardware trigger and software filters.
Systems work together to identify and measure the flux of cosmic gamma Systems work together to identify and measure the flux of cosmic gamma rays with energy 20 MeV - >300 GeV.rays with energy 20 MeV - >300 GeV.
Calorimeter
Tracker
ACD [surrounds 4x4 array of TKR towers]
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GLAST LAT CollaborationGLAST LAT Collaboration
United States• California State University at Sonoma• University of California at Santa Cruz - Santa Cruz Institute of Particle Physics • Goddard Space Flight Center – Laboratory for High Energy Astrophysics• Naval Research Laboratory• Ohio State University• Stanford University (SLAC and HEPL/Physics)• University of Washington• Washington University, St. LouisFrance• IN2P3, CEA/SaclayItaly• INFN, ASI
Japanese GLAST Collaboration• Hiroshima University• ISAS, RIKEN
Swedish GLAST Collaboration• Royal Institute of Technology (KTH)• Stockholm University
PI: Peter MichelsonPI: Peter Michelson (Stanford & SLAC)
~120 Members (including ~60 Affiliated Scientists, plus 20 Postdocs, and 25 Graduate Students)
LAT Project is a partnership between NASA and DOE, with international contributions from France, Italy, Japan and Sweden.
Managed at Stanford Linear Accelerator Managed at Stanford Linear Accelerator Center (SLAC).Center (SLAC).
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Highlights of Recent ActivitiesHighlights of Recent Activities
• Successful Mission CDR!
• Collaboration meeting at SLAC 27-30 September
– Instrument test data analysis workshop
– Hardware and software status
– Science organization and planning
– Operations planning
– Cooperation with other experiments (multi-wavelength planning)
– GeV-TeV Symposium (joint with Mission Science Working Group)
• Senior Scientist Advisory Committee
– year 1 data release plan proposal
– new members
– performance updating
– science planning policies
• Data Challenges
– very successful DC1; planning/working now for DC2
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Instrument Test Data AnalysisInstrument Test Data Analysis
• A suite of detailed test data-taking runs is being defined for each stage of the build. Using the data, there are two basic categories of data analysis:– (mostly) automated, basic go/no-go tests. These are done by
I&T, with ~instant result turn-around to support the schedule.– this work:this work: more detailed analyses using (mostly) the same
data. A key opportunity to look for more subtle, sophisticated, and detailed effects:
» To uncover and quantify any instrumental effects early that could have an impact on science data analysis & feedback realism into the Monte Carlo
» Are there additions to the go/no-go test suite?» To apply reconstruction algorithms to real data » To start the work that will evolve in the Instrument
Science Operations Center (ISOC)» To grow a group to participate in the beam tests analysis
effort (after instrument delivery)
– Relies on strong collaboration-wide support. First workshop in June, second in September. Regular meetings via vrvs.
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Operations Phase LAT Organization ChartOperations Phase LAT Organization Chart
Dr. Rob Cameron appointed LAT Instrument Science Operations Center manager
– extensive operations experience at SAO / Chandra X-ray Center
LAT Collaboration Science Groups (LSGs) responsible for collaboration’s analysis and extraction of science results from LAT data
– 11 Science Groups plus Multi- Coordination Working Group
– each science group to have 2 co-leads; with one resident at Stanford
– day-to-day efforts coordinated by Analysis Coordinator, also resident at Stanford-SLAC
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Science Analysis GroupsScience Analysis Groups
process started for updating the groups groups organized around expected collaboration publications, particularly
during the 1st year all-sky survey phase; each group should have responsibility for 2-3 key (category 1) papers.
Science Analysis Groups1. Catalogs
2. Galactic Diffuse and Molecular Clouds3. Extragalactic Diffuse4. Blazars and Other AGNs5. Other Galaxies (including clusters)6. Pulsars, SNRs, and Plerions7. Unidentified Sources and Population Studies8. Dark Matter and Exotic Physics9. Gamma-Ray Bursts10. Solar System Sources11. Calibration and Analysis Methods
LAT Multiwavelength Observation Coordination Group
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Space at SU – SLAC for ISOC and Analysis effortsSpace at SU – SLAC for ISOC and Analysis efforts
Fred Kavli Building at SLAC – KIPAC(Kavli Institute of Particle Astrophysics and Cosmology) Roger Blandford, Director Steve Kahn, Deputy Director
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Space at SU – SLAC for ISOC and Analysis effortsSpace at SU – SLAC for ISOC and Analysis efforts
new building on campus - replacement space for HEPL - campus part of KIPAC
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GeV-TeV Symposium 30 September at SLACGeV-TeV Symposium 30 September at SLAC
LAT Team and MissionScience Working Grouphave held ~annual jointscience symposia on a wide variety of topics.
This year: GeV-TeV Astrophysics inthe GLAST Era
+ Very useful workshop discussion about
cooperation among experiments!
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Data ChallengesData Challenges
• DC1 early alpha-testing. “End-to-end” testing of analysis software.• Provide feedback on what works and what is missing from the data
formats and tools.• Walk before running: design a progression of studies.
– DC1. Modest goals. Contains most essential features of a data challenge. • 1 simulated day all-sky survey simulation• find the sources, including GRBs• a few physics surprises• exercise:
– exposure, orbit/attitude handling, data processing pipeline components, analysis tools
– DC2 in 2005. More ambitious goals. ~One simulated month.• toy one-month catalog.• add source variability (AGN flares, pulsars). add GBM.
– DC3 in 2006. Support for flight science production.
see http://www-glast.slac.stanford.edu/software/Workshops/Feb04DC1CloseOut/coverpage.htm
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The DC1 SkyThe DC1 Sky
E>100 MeVwith some other cuts for illustration
Lots to analyze! A few surprises to find…
One day all-sky survey. Generated E>20 MeV.
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Data Challenge 1 SkyData Challenge 1 Sky
isotropic diffuse
Sources – 3EG and more, with a twist
3C273
3C279
a number of physicssurprises in the DC1data, including:• 110 GeV gamma-ray line source at the galactic center• new source populations• all surprises were detected at some level!
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LAT Data Challenges: Updated Plan for DC2LAT Data Challenges: Updated Plan for DC2
DC2, based on lessons from DC1– 1 simulated month of all-sky survey gammas (backgrounds: see next slide)– key sky addition: source variability
• AGN variability, including bright flares, quiescent periods• expand burst variety. Include GBM.• pulsars, including Gemingas, w/ orbit position effects.
– more realistic all-sky attitude profile– background rate varies with orbit position– more physics surprises– update geometry (including s/c); add nominal hardware problems (and
misalignments?); add deadtime effects and corrections– Analysis Goals:
• produce toy 1-month catalogproduce toy 1-month catalog• try out transient releases and quicklook analyses, monitor sourcestry out transient releases and quicklook analyses, monitor sources• point source sensitivity and localization studies• try first systematic pulsar searches (timing!)• diffuse analyses• recognize simple hardware problems (connect with ISOC)• benchmark processing times, data volume, data transfers.
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SummarySummary
• Strong involvement of physicists at all levels of the project– ready for earliest instrument test data analysis– strategizing/prioritizing as issues arise– getting ready early to do great science via data challenges
and updating organization of science groups– increasing cooperation with other experiments, helping to
lead the way.
• Very strong support by SLAC of the international science collaboration and the management of the fabrication.
• The hardware is coming! Great excitement in a team that
