THE FIRST 4 MONTHS
Richard Dubois
SLAC
on behalf of the Fermi LAT Collaboration
Year 1 Science Operations Timeline Overview
spacecraft
turn-on checkout
week
LAUNCH
week
LAT,
GBM
turn-on
check
out
week
“first light”
whole sky
Start Year 1
Science Ops
Observatory
renaming
sky survey + ~weekly GRB
pointed + sky
survey tuning
week
Start Year 2
Science Ops
repoints + extraordinary TOOs
month
12 m o n t h s
L+60 days
2nd
Symposium
June 11, 2008
initial tuning/calibrations
in-depth instrument studies
Release Flaring and Monitored Source Info
GBM and LAT GRB Alerts
continuous
release of new
photon data
GI Cycle 1
Funds Release
Fellows Year 1
Start
GI Cycle 2
Proposals
LAT 6-month
high-confidence
source release, GSSC
science tools advance
release
LAT Year 1 photon
data release PLUS
LAT Year 1 Catalog
and Diffuse Model
> 2000 AGNs
Possibilities
blazars and radiogal = f(q,z)
evolution z < 5
Sag A*
starburst galaxies
galaxy clusters
measure EBL
unIDs
10-50 GRB/year
GeV afterglow
spectra to high energy
g-ray binaries
Dark Matter
neutralino lines
sub-halo clumps
Pulsar winds
m-quasar jets
Pulsars
Cosmic rays and clouds
acceleration in Supernova remnants
OB associations
propagation (Milky Way, M31, LMC, SMC)
Interstellar mass tracers in galaxies
emission from radio and X-ray pulsars
blind searches for new Gemingas
magnetospheric physics
pulsar wind nebulae
LAT images the sky one photon at
a time: g-ray converts in LAT to an
electron and a positron ; direction and
energy of these particles tell us the
direction and energy of the photon
GBM
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France
– IN2P3, CEA/Saclay
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Italy
– INFN, ASI, INAF
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Japan
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Hiroshima University
ISAS/JAXA
RIKEN
Tokyo Institute of Technology
Sweden
– Royal Institute of Technology (KTH)
– Stockholm University

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
United States
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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
…. Transient class
Source class
Diffuse class
multiple scattering
dominates
Finite pitch of
Si strips
Aeff Ω
(cm2 sr)
Years
Ang. Res.
(100 MeV)
Ang. Res.
(10 GeV)
Eng. Rng.
(GeV)
EGRET
1991–00
5.8°
0.5°
0.03–10
750
1.4 ×
106/yr
AGILE
2007–
4.7°
0.2°
0.03–50
1,500
4 × 106/yr
Fermi
LAT
2008–
3.5°
0.1°
0.02–300
25,000
1 × 108/yr
# g-rays
• LAT has already surpassed EGRET and AGILE celestial gamma-ray totals
• Unlike EGRET and AGILE, LAT is an effective All-Sky Monitor
whole sky every ~3 hours
EGRET
AGILE (ASI)
CGRO EGRET
Fermi / LAT
June 11, 2008
11:30 am (EDT)
June 11, 2008
12:05 pm (EDT)
Fermi MISSION ELEMENTS
Time from end of run
onboard to delivery of
photon list
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GPS
msec
-
• Telemetry 1 kbps
•
Fermi Spacecraft
DELTA
7920H
Peak time = 8 hrs
Large Area Telescope
& GBM
TDRSS SN
S & Ku
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S
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GN
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Schedules
Mission Operations
Center (MOC)
GRB
Coordinates Network
Fermi Science
Support Center
Schedules
Alerts
Data, Command Loads
LAT Instrument
Science
Operations Center
(SLAC)
White Sands
HEASARC
GBM Instrument
Operations Center
LAT Instrument Science Operations Center
•
LAT ISOC facilities at SLAC are running at full speed!
– Receiving ~15 GB of raw data from the LAT each
day
•
Flight Operations Team
– LAT operation and monitoring/trending
– Data receipt and archiving
Science Operations Team
– Science data monitoring/trending
– Instrument performance analysis
– Initial calibration generation
Science Analysis Systems Team
– Processing infrastructure support
– Event reconstruction and simulation codes
– Science analysis tools
– Monte Carlo data generation
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A large international team of scientists from the LAT
Collaboration came to SLAC to support Fermi’s 60day on-orbit commissioning period
– Now largely automated with remote spot
checking and alarms
9.5 years still to run
Literally lights out now!
Principal Computing Resources
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SLAC compute farm (Fermi allocation)
– 800 CPUs in batch farm running LSF (+ peak loads of >2000)
– 350 TB disk = 100 TB NFS + 250 TB xroot – 32 TB raid 10 Sun thumpers
– 250 TB tapes in silo (HPSS)
Lyon compute farm (CCIN2P3, France)
– 400 CPUs in batch farm running BQS
– few TB disk allocated for all Fermi uses (transfer generated files to SLAC)
– seamlessly used by pipeline from SLAC
Plans for using an Italian center (Bologna or Padova)
Extensive use of relational DB
– Two ‘Niagara’ redundant Oracle servers each with 1.5 TB raid disk
• Science monitoring
• LAT+Spacecraft ‘housekeeping’ trending
• Bookkeeping (dataCatalog, processing config, etc.)
• Science data (e.g., GRB catalog)
• Resource trending
0.015%
0.5%
Sep-08
0.003%
0.001%
0.7%
Aug-08
Oct-08
1.7%
1.3%
0.007%
0.7%
0.068%
1.770%
1.4%
1.7%
2.8%
2.5%
2.0%
1.4%
0.332%
1.2%
0.294%
0.051%
Jul-08
Jun-08
May-08
Apr-08
Mar-08
0.350%
0.527%
0.4%
Jan-08
Feb-08
0.513%
0.5%
0.589%
1.371%
Dec-07
Nov-07
Oct-07
Sep-07
Aug-07
0.461%
3.000%
Jul-07
0.084%
0.011%
0.5%
3.2%
3.7%
7.1%
7.357%
7.8%
7.3%
8.000%
Jun-07
May-07
0.000%
0.022%
1.000%
Apr-07
2.000%
0.947%
4.000%
Mar-07
Reliability
9.000%
Pipeline Failure
Job Failure
7.000%
L1Proc is 0.13%,
6.000%
0.02% with ‘AutoRetry’
5.000%
Launch
Data!
GLAST Large Area Telescope
First Light
GLAST First Light Seminar, 26 Aug 2008
17
GLAST Large Area Telescope
First Light
GLAST First Light Seminar, 26 Aug 2008
18
First Light
GLAST Large Area Telescope
First Light
GLAST First Light Seminar, 26 Aug 2008
20
First Light
First Light
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~4-day First Light
exposure, June 30
– July 3, 2008
Orthographic
projection
In the simplest model, the emission should depend on 4 parameters: spin period,
magnetic field, magnetic dipole inclination, and viewing angle
 luminosity derived from
rotational energy
radio emission cone
Erot = ½ I W2
.
E = - B2R6W4 / c3
 derived parameters:
.
rotational age : t = W/2W
.
B field: B = 3.2x1019 (PP)1/2 G
.
spin-down power: L = IWW
g-ray emission
fan beam
Center of the Milky Way
PSR J1706-44
Vela (2 cycles, P=89.3 ms)
Geminga (2 cycles, P=237.1 ms)
In a few days, Fermi
confirmed the EGRET
pulsars and has found
new g-ray pulsars as well
PSR B1706-44 (2 cycles, P=102.4 ms)
PSR B1055-52 (2 cycles, P=197 ms)
Crab pulsar (P=33.4 ms)
CTA 1 pulsar (2 cycles, P=315.86 ms)
Vela (2 cycles, P=89.3 ms)
Geminga (2 cycles, P=237.1 ms)
CTA 1:
Abdo, et al.,
Science
Express,
Oct 2008
PSR B1706-44 (2 cycles, P=102.4 ms)
PSR B1055-52 (2 cycles, P=197 ms)
Crab pulsar (P=33.4 ms)
CTA 1 pulsar (2 cycles, P=315.86 ms)
3EG J0010 +7309 95% error box
RX J00070+7302
+
Fermi 95% error box
• exhibits all characteristics of a young highenergy pulsar (characteristic age ~1.4 x 104 yr),
which powers a synchrotron pulsar wind nebula
embedded in a larger SNR.
• spin-down luminosity ~1036 erg s-1, sufficient
to supply the PWN with magnetic fields and
energetic electrons.
CTA 1 supernovae remnant
• g-ray source at l,b = 119.652, 10.468;
95% error circle radius =0.038° contains the X-ray
source RX J00070+7302, central to the PWN
superimposed on the radio map at 1420 MHz.
• pulsar off-set from center of radio SNR; rough
estimate of the lateral speed of the pulsar is ~450 km/s
3C454.3
Supermassive black hole
8 billion light-years from us
Flaring sources
• Automated search for
flaring sources on 6 hour, 1
day and 1 week timescales.
• 11 Astronomers telegrams
– Discovery of new gammaray blazars PKS 1502+106,
PKS 1454-354
– Flares from known gammaray blazars: 3C454.3, PKS
1510-089,3C273, AO
0235+164, PSK 0208-512,
3C66A, PKS 0537-441
– Galactic plane transients:
J0910-5041, 3EG J09033531
http://www.astronomerstelegram.org/
•
LAT has reported 3 high-energy bursts since launch
long-duration bursts
First detection of short-duration burst at high energy


For the first time, can
study time structure >
tens of MeV.
Feature in the LC:
— pulse in interval “a”
disappears at LAT
energies.
PRELIMINARY
PRELIMINARY
Soft-to-hard spectral evolution followed
by spectral softening
X-ray binaries / Microquasars
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LSI +61 303 clearly detected
Expect orbital phase dependent flux and spectrum variations
Orbital phase resolved analysis in progress
GeV/TeV variability patterns give strong constraints on X-ray binaries
models
Flux variations with orbital phase
for E>400 GeV discovered by MAGIC
Telescope (Science, 2006)
Science Accomplishments in a Nutshell
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Mapping and measuring the entire sky at a unprecedented angular and
energy resolution and statistical accuracy
Detected several pulsars, including all the EGRET ones and several new
ones
Detected several hundred sources
– First list of bright high-significance sources in preparation
Mapping the diffuse Galactic emission and measuring its spectrum
Discovered flares from several AGN reported in ATels
Detected the binary LSI+61 303
Detected the moon and the quiet sun (and earth)
Measured the light-curve and spectrum of the Vela pulsar (paper submitted)
Discovered a radio-quiet pulsar in CTA1 (first Science pub!)
Resolved the LMC
Detected three GRBs, one up to several GeV, reported in GCNs
Measuring the cosmic-ray electron spectrum
Detected two Galactic plane transients
……
– The Fermi Gamma-ray Space Telescope is fully operational..
– In just a few days, the Large Area Telescope (LAT) corroborated many of the
great discoveries of EGRET; now finding new sources as well;
– Undoubtedly, the most exciting is yet to come as we have completed 4
months of the 1st year all-sky survey phase;
- with time probe deeper and deeper into the high-energy Universe