GLAST: Status and Prospects

1
GLAST Status and Prospects

• S. W. Digel
• Co-lead ISOC Science Operations
• Co-chair KIPAC GLAST Physics Department

2
Overview

• GLAST and the Large Area Telescope Background
• Relationship of SLAC to Development and
  Operations
• LAT Operations at SLAC
• Roles and responsibilities of the ISOC
• Status of GLAST
• GLAST in Launch Early Operations (LEO)
• Prospects
• Perspective on GLAST
• Scientific Prospects (Briefly)
• Summary

3
Gamma-ray Large Area Space Telescope Background

• Instrument concept for the LAT was developed by
  W. B. Atwood, then at SLAC
• GLAST collaboration was formed in the early
  1990s, with substantial Stanford/SLAC
  representation
• Early support from the DOE was important for
  development of the instrument concept
• In 1999, NASA decided to go ahead with the
  mission, which took the GLAST name
• LAT proposal (PI P. Michelson/Stanford) with DOE
  support was successful
• Joint NASA/DOE mission in the U.S., with
  international support from France, Germany (GBM),
  Italy, Japan, and Sweden

4
GLAST Background (2)

• Project Office for development of the LAT is at
  SLAC (at least for a few more weeks)
• Mechanical, Thermal, and Electronics design work
  was done at SLAC, including the construction of
  the LAT Testbed
• The LAT was integrated and tested at SLAC
• SLAC hosts the LAT Instrument Science Operations
  Center
• KIPAC/SLAC Faculty, Staff, Postdocs and Students
  were actively involved in supporting LAT testing,
  planning for operations and analysis in the LAT
  collaboration
• And now flight data are arriving

5
ISOC in the LAT Collaboration

• The ISOC is the core of the LAT support
  activities at SLAC
• ISOC has close connections to LAT Science Groups
• ISOC science staff participate in all Science
  Groups
• AGN GRB Science groups Automated Science
  Processing
• The LAT collab. participates in the ISOC
• Some SO application development is supported, and
  analyses are coordinated with the Calibration
  Analysis Science Working Group
• SAS and FO too have support from the
  collaboration, with some developers resident at
  SLAC
• During 60-day LEO 50 LAT collaborators will
  visit SLAC to support operations as Duty
  Scientists and participate in analyses

6
ISOC Organization
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Roles Responsibilities of the ISOC

• Flight Operations (FO)
• Command planning
• Generating and validating commands and command
  sequences
• Monitoring health and safety of the LAT
• Maintaining and modifying flight software and the
  LAT Testbed
• Science Operations (SO)
• Monitoring data deliveries, processing, LAT
  performance
• Calibration and optimization of LAT performance
• Supporting mission planning
• Processing and archiving Level 1 and Level 2
  (Automated Science) data
• Science Analysis Systems (SAS)
• Maintaining and optimizing the software that
  produces science data products
• Distributing science data products and instrument
  analysis tools to the LAT Collaboration and the
  GLAST Science Support Center (GSSC)

In each of these areas, important unique
expertise and facilities are at SLAC
FSW developers, LAT Testbed
Integration Test and Instrument Analysis team
heritage, Mission Support Room
Software project, database, and data management
on a large scale SLAC Computer Farm
8
Status of GLAST

• As you heard 3 times yesterday Launched on June
  11
• LAT was turned on 2 weeks ago telemetry
  surpassed 1 billion events last Friday
• Will complete ¼ orbit during this presentation
• We are still very much within the 60-day LEO
  phase of testing, calibrating, and tuning
• Important aspects of that work remain but so far
  so good
• Extremely exciting and busy time for the ISOC and
  LAT collaboration!

9
Status of GLAST (2)

• ISOC is running 24 hours per day Flight
  Operations and Science Operations (shift
  coordinator E. do Couto e Silva) in the Mission
  Support Room (Bldg 84) and currently has
  personnel at the Mission Operations Center (NASA
  GSFC)
• The last time it was dark

1235 am June 24
Minutes later FO Shifter, SO Duty Scientists and
Shift Coordinator arrived to track the turn-on of
the LAT over night
1254 am June 25 Turn-on continues
10
Some Details for the Near Future

• Principal studies remaining for LEO
• Complete calibration (pedestals and gains)
• Alignment (internal and with spacecraft)
• Background studies characterizing the particle
  environment
• Configurations/threshold, trigger, and filter
  updates for the on-orbit trigger rates
• Updating perimeter of the South Atlantic Anomaly
• Commissioning on-board GRB detection
• Commissioning ASP ground processing of flares
  and GRBs
• Validating other observing modes ARR, ToO, CVZ,
  limb following, and 2-target
• Refining survey mode
• Updating instrument response functions

11
More on Status

• Remarkably few unanticipated issues no
  roadblocks to science
• Pointing control, timing, alignment, thermal
  stability are all looking good

12
Prospects for GLAST Perspective

• The combination of area, FOV, angular resolution,
  readout time, and observing efficiency together
  represent a tremendous advance for astronomy at
  GeV energies
• Within the next several weeks the LAT should
  detect more celestial g-rays than have been seen
  by all previous and current missions
• Capability for studying transient sources and
  making deep observations of faint or diffuse
  sources is absolutely world beating

Years Ang. Res. (100 MeV) Ang. Res. (10 GeV) Eng Rng (GeV) Aeff O (cm2 sr) g-rays
EGRET 199100 5.8 0.5 0.0310 750 1.4 106
AGILE 2007 4.7 0.2 0.0350 1,500 4 106/yr
GLAST LAT 2008 3.5 0.1 0.02300 25,000 1 108/yr
13
Progression of Sensitivity

• The questions that can be investigated deepen
  with improvements in sensitivity (to state the
  obvious)

OSO-III (gt50 MeV)
14
Scientific Prospects

• As S. Kahn described yesterday, the SLAC
  scientific focus on GLAST will be in three main
  areas
• Indirect detection of dark matter
• Particle acceleration in cosmic sources
• Relativistic outflows
• E. do Couto e Silva on GLAST and GRBs and G.
  Madejski on GLAST and TeV Astrophysics will
  describe opportunities provided by GLAST in these
  areas
• Gamma rays are the probe
• Produced in well-understood interactions (pion
  decay, Bremsstrahlung, inverse Compton) with
  high-energy particles
• Unattenuated (or attenuated in physically
  revealing ways) and they point back to their
  sources

15
Prospects are Interrelated

• Research themes will not always factor on the
  sky, especially for diffuse signals
• For example, Dark matter annihilation would be
  much easier to detect if not for the foreground
  glow from cosmic-ray interactions with
  interstellar gas and stars (diagnostic of
  particle acceleration in the Milky Way)
• Unique combination of expertise in KIPAC within
  the LAT collaboration, or really any place

Simulation of Milky Way like galaxy in Dark
Matter Density as seen from M31 (Taylor) No
backgrounds
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Summary

• GLAST is in orbit and the LAT is in the midst of
  its checkout looking good
• LAT has ground-breaking capabilities for
  observations in the GeV range
• SLAC/KIPAC hosts the ISOC and is centrally
  involved with LAT operations, processing, and
  analysis
• The scientific scope for the LAT is very broad,
  with Indirect detection of dark matter, Particle
  acceleration in cosmic sources, Relativistic
  outflows as important themes
• SLAC/KIPAC has a unique combination of expertise
  on these topics as well as deep understanding of
  the LAT