July 7, 2008 SLAC Annual Program Review Page 1

GLAST: Status and Prospects

S. W. Digel

Co-lead ISOC Science Operations

Co-chair KIPAC GLAST Physics Department

July 7, 2008 SLAC Annual Program Review Page 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 (L&EO)

* Prospects– Perspective on GLAST– Scientific Prospects (Briefly)

* Summary

July 7, 2008 SLAC Annual Program Review Page 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

July 7, 2008 SLAC Annual Program Review Page 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

July 7, 2008 SLAC Annual Program Review Page 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 L&EO 50+ LAT collaborators will visit SLAC to support operations as Duty Scientists and participate in analyses

PI/SpokespersonP. Michelson

Instrument Scientist (IS)S. Ritz

LAT Instrument ScienceOperations Center (ISOC)

R. Cameron, Manager

LAT Collaboration ScienceGroups (LSG)

Analysis Coordinator (rotating)

E/PO

Coordinator: L. Cominsky

LAT Collaboration SeniorScientist Advisory Committee

(SSAC)

N. Gehrels, Chair

LAT Operations SteeringCommittee

W.N. Johnson, S. Ritz, Co-chairs

Flight Operations

Science Operations

Science Analysis Systems

Publication Review Board

Membership and collaboration policies

Group 2

Group 4

Group 1

Group 3

Group 6 Group 5

Group 7 …Group N

July 7, 2008 SLAC Annual Program Review Page 6

ISOC Organization

ISOC

Manager: R. CameronDeputy: E. do Couto e Silva,

Deputy: R. Dubois

Commanding, Health and Safety

L. Bator

Flight Operations

J. Thayer

Science Operations

S. Digel, E. do Couto e Silva

Science AnalysisSystems

R. Dubois

Flight Software

J. Thayer

Support

Admin: B. Valdez

July 7, 2008 SLAC Annual Program Review Page 7

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)

FSW developers, LAT Testbed

In each of these areas, important unique expertise and facilities are at SLAC

Integration & Test and Instrument Analysis team heritage, Mission Support Room

Software project, database, and data management on a large scale & SLAC Computer Farm

July 7, 2008 SLAC Annual Program Review Page 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 L&EO 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!

July 7, 2008 SLAC Annual Program Review Page 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: 12:35 am June 24

12:54 am June 25Turn-on continues

Minutes later FO Shifter, SO Duty Scientists and Shift Coordinator arrived to track the turn-on of the LAT over night

July 7, 2008 SLAC Annual Program Review Page 10

Some Details for the Near Future

* Principal studies remaining for L&EO:– 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

July 7, 2008 SLAC Annual Program Review Page 11

More on Status

* Remarkably few unanticipated issues – no roadblocks to science

* Pointing control, timing, alignment, thermal stability are all looking good

July 7, 2008 SLAC Annual Program Review Page 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 -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

YearsYears Ang. Res.Ang. Res.(100 MeV)(100 MeV)

Ang. Res. Ang. Res. (10 GeV)(10 GeV)

Eng Rng Eng Rng (GeV)(GeV)

AAeffeff Ω Ω

(cm(cm22 sr) sr)# # raysrays

EGRETEGRET 1991–1991–0000 5.8°5.8° 0.5°0.5° 0.03–100.03–10 750750 1.4 × 101.4 × 1066

AGILEAGILE 2007–2007– 4.7°4.7° 0.2°0.2° 0.03–500.03–50 1,5001,500 4 × 104 × 1066/yr/yr

GLAST LATGLAST LAT 2008–2008– 3.53.5°° 0.1°0.1° 0.02–3000.02–300 25,00025,000 1 × 101 × 1088/yr/yr

July 7, 2008 SLAC Annual Program Review Page 13

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

Progression of Sensitivity

OSO-III (>50 MeV)EGRET (>100 MeV)Simulated LAT (>100 MeV, 1 yr)Simulated LAT (>1 GeV, 1 yr)

July 7, 2008 SLAC Annual Program Review Page 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

July 7, 2008 SLAC Annual Program Review Page 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

July 7, 2008 SLAC Annual Program Review Page 16

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