Fermi_PIC2009.ppt

GammaGamma--Ray Particle Ray Particle Astrophysics:Astrophysics:Astrophysics:Astrophysics:

the first year of the the first year of the Fermi GammaFermi Gamma--rayrayFermi GammaFermi Gamma--ray ray Space TelescopeSpace Telescope

TsunefumiTsunefumi MizunoMizunoHiroshima Univ.Hiroshima Univ.

on behalf of the Fermi on behalf of the Fermi CollaborationCollaboration

Tsunefumi Mizuno 1September 02, 2009, Kobe, JapanSeptember 02, 2009, Kobe, Japan

Fermi_PIC2009.ppt

Plan of the Talk Plan of the Talk

• Review of the high energy gamma-ray missions• Highlights of the Fermi’s first year results:g g y

Gamma-ray burstsimplication on fundamental physics and UHECRs

ti f j t ith hi h t Γproperties of jets with highest ΓGalactic cosmic-rays and dark matter

Direct measurement of Galactic cosmic-raysDirect measurement of Galactic cosmic raysGalactic diffuse gamma-rays as an indirect probe of Galactic

CRsSelected Galactic/extragalactic gamma-ray objects

focus on the relation to Galactic CRs and UHECRs

Tsunefumi Mizuno 2

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R i f Hi hR i f Hi h E GE GReview of HighReview of High--Energy GammaEnergy Gamma--ray ray Astrophysics MissionsAstrophysics Missionsp yp y

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Fermi_PIC2009.pptGeV Gamma-ray Astrophysics(Eγ = a few 10s MeV to ~100 GeV)

• 1967 to 1968 -- OSO-3 : First detection of γ-rays from the Gal. plane• 1972 to 1973 -- SAS-2 : Crab, Vela, and Geminga• 1975 to 1982 -- COS-B : >=20 γ-ray sources

EGRET:(on the Compton Gamma Ray Observatory)271 (>5σ) γ ray sources + detailed map of the Galaxy271 (>5σ) γ-ray sources + detailed map of the Galaxy

1991 -- 2000 • 2007 to present -- AGILE

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A new gamma-ray satellite every 10 or 15 years• 2008 to present -- Fermi

Fermi_PIC2009.pptTeV γ-ray Astrophysics withAtmospheric Cherenkov Imager Arrays (Eγ >= 100 GeV)

HESS galactic survey

Nearly 100 sources under study.

CANGAROO III, Australia

H.E.S.S., NamibiaMAGIC II, Canary islands, Spain

CTA (2013~)

VERITAS, Arizona, USA

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Very important but not covered by this talk. See, e.g., talk by Schwanke in PIC 08

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Fermi LaunchFermi Launch

• Launched from Cape Canaveral Air Station on June 11, 2008

Science Operation on Aug 4 2009• Science Operation on Aug 4, 2009• Orbit: 565 km, 26.5o (low BG)

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Large Area Telescope (LAT) on FermiLarge Area Telescope (LAT) on Fermi

20 MeV to >= 300 GeVFOV: 2.4 sr

• Tracker: Si-strip detectors & W convertersIdentification and direction measurement of γ-rays

• Calorimeter: hodoscopic CsI scintillatorsEnergy measurement

• ACD: segmented plastic scintillatorsBG rejection

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j

Technology developed through HEP experimentsSee Atwood et al. (ApJ 697, 1071, 2009) for detail

Fermi_PIC2009.ppt

GammaGamma--ray Burst Monitor (GBM) on Fermiray Burst Monitor (GBM) on Fermi

Views entire unocculted sky with• 12 NaI detectors: 8 keV - 1 MeV• 2 BGO detectors: 150 keV - 40 MeV

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LAT+GBM=> more than 7 decades of energy

OK, let’s start with GRBs

Fermi_PIC2009.ppt

Highlights from Fermi’s 1Highlights from Fermi’s 1stst year (1): year (1): g gg g y ( )y ( )GammaGamma--ray Burstsray Bursts

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GammaGamma--Ray Bursts Overview (1)Ray Bursts Overview (1)• Discovered in 1967• Cosmological origin (BeppoSAX, BATSE)

Large apparent energy release: Eiso ~ 1052 - 1054 ergL L t f t f j t Γ > 100 ( f f QSO d 10 f AGN)Large Lorentz factor of jet: Γ >= 100 (a few for μ-QSO and ~10 for AGN)Energetics may be consistent with origin of UHECRs

• Peak in ~ MeV gamma-raysBand function: smoothly joins two power-lawsBand function: smoothly joins two power lawsSynchrotron radiation of ultra-relativistic electrons in jet?

Tsunefumi Mizuno 100.01 0.1 1 10 100 MeV

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GammaGamma--Ray Bursts Overview (2)Ray Bursts Overview (2)

2 s

• Bimodal distribution of duration timeShort (<2 s) GRB: progenitor unknown

Merger of NSs or BHs?Long (>2 s) GRB: association with supernova

Core collapse supernovaeT90 (duration) in seconds

Core-collapse supernovae

• Gamma-ray emission mechanism not fully understood yet

• Fermi observation of GRBs is expected toconstrain the emission mechanismconstrain the bulk Lorentz factor of jetconstrain the bulk Lorentz factor of jetlimit on Lorentz invariance violationsearch for the clue of UHECRs probe the extragalactic background light (star formation in early

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p g g g ( yuniverse)

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Fermi GRB Fermi GRB SkymapSkymap (as of Jun. 29, 2009)(as of Jun. 29, 2009)• 7 long + 2 short GRB by GBM+LAT, from 8 keV to tens of GeV• Short & long GRBs: similar phenomenology at high energy?

241 GBM GRBs9 LAT GRB

Abdo et al.Sci.323, 1688 (2009)

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9 LAT GRBs129 In Field-of-view of LAT

Abdo et al., submitted to Nature(arXiv:0908.1832)

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GRB080916C Prompt Emission (<=100s)GRB080916C Prompt Emission (<=100s)• z=4.35 +/- 0.15 (GROND; GCN8257) 8-260 keV

• More than 3000 LAT photons, 145 above 100 MeV and 14 above 1 GeV 260 keV-5 MeV

• Delayed HE onset (1st peak not seen > 100 MeV)

Opacity effect (γγ->e+e-)? But LAT (all)

no evidence of spectral cutoff

• Single Band-function dominant for 6 decades of

>100 MeVdominant for 6 decades of energy

Lack of prominent SSC component implies high >1 GeV

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magnetic field or high γe

0 20 40 60 80s

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LongLong--Lived HE EmissionLived HE Emission• HE (>100 MeV) emission shows different temporal behavior

Temporal break in LE emission while no break in HE emissionCascades induced by ultra-relativistic ions?Cascades induced by ultra relativistic ions?Angle-dependent scattering effects?

Flux in LAT/GBM bandsFlux in LAT/GBM bands• E>100 MeV

index = -1.2 +/- 0.2• E= 50 -300 keV

i d 0 6 > 3 3index: ~-0.6 => ~-3.3(at ~T0+55s)

Photon Index (LAT only)no significant evolutionno significant evolution (Epeak gradually decreases)

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Constraints on Bulk Lorentz FactorConstraints on Bulk Lorentz Factor• Large luminosity and short variability time imply large optical depth due to γγ -> e+e- (compactness problem)

Small emission region: R ~ cΔtτγγ(E) ~ (11/180)σTN>1/E/4πR2

τγγ(1 GeV) ~ 7x1011 for a typical GRB of fluence=10-6 erg/cm2, z=1, Δt=1 s

• Relativistic motion (Γ >> 1) can reduce optical depth• Relativistic motion (Γ >> 1) can reduce optical depthLager emission region: R ~ Γ2cΔtReduced photon # densities:

N>1/E Γ2β+2 (note: β ~ -2.2)( β )Blue shift of energy threshold:

Eth ΓBlue shift of spectrum:

N(E) = (ΓE)β+1N(E) = (ΓE)β+1

Overall reduction of optical depth:Γ2β+2 /Γ4= Γ2β-2 ∼Γ-6.4 (<=10-12 for Γ=100)

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• Limit from GRB 080916C: Γ 890±21(Largest ever observed as of May 2009)

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Limits on Lorentz Invariance Violation (LIV)Limits on Lorentz Invariance Violation (LIV)16 5

• Some QG models violate Lorentz invariance. A high-energy photon would arrive after a low-energy one

16.5 s

would arrive after a low energy oneemitted simultaneously.

GRB080916C:

(Jacob & Piran 2008. n=1 for linear LIV)

G 0809 6C13.2 GeV @ T0+16.5 sMQG, 1 > (1.5±0.2) x 1018 GeV/c2,

1/10 of the Plank mass and the1/10 of the Plank mass and the highest as of May 9, 2009.

i MPulsar GRB GRBAGN AGN GRB080916C Planck mass

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min MQG

(GeV)

Pulsar

(Kaaret 99)

GRB

(Ellis 06)

GRB

(Boggs 04)

AGN

(Biller 98)

AGN

(Aharonian 08)1015 1016 1017 1018 1019

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GRB090510 (1)GRB090510 (1)

Abdo et al. 2009Submitted to Nature(arXiv:0908.1832)

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GRB095010 (2)GRB095010 (2)10

1GeV

• Time vs. photon energyLAT all eventsE>100 MeV

• Short GRB with > 150 photons above0.1

0.01

Short GRB with > 150 photons above 100 MeV• 31 GeV @ ~T0+0.83s

S lid d d tt d li LIV f 1• Solid and dotted line are LIV for n=1 and 2, respectively• Several assumptions of tstart indicated by different colorsby different colors

• Even the conservative case (black line) implies MQG, 1 > 1.19 MPlanck

• Other important findingsdeviation from Band functionhighest Epeak: 5.1 MeV (Band+PL

model fit)

Tsunefumi Mizuno 180 0.5 1 1.5 2 (s)

model fit)delayed onset of LAT emission by 0.1-

0.2 shighest Γmin (~1200)

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Highlights from Fermi’s 1Highlights from Fermi’s 1stst year (2): year (2): Direct Measurements of GalacticDirect Measurements of GalacticDirect Measurements of Galactic Direct Measurements of Galactic

CR ElectronsCR Electrons

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Fermi_PIC2009.pptIntroduction (1):Introduction (1):What Can We Learn from HE eWhat Can We Learn from HE e--/e/e++ and p/p ? and p/p ?

• Inclusive spectra: e- + e+

Electrons, unlike protons, lose energy rapidly by Synchrotron d I C t t hi h th b th band Inverse Compton: at very high energy they probe the nearby

sources

• Charge composition: e+/(e- + e+) and p/(p + p) ratios• Charge composition: e+/(e + e+) and p/(p + p) ratiose+ and p are produced by the interactions of high-energy cosmic

rays with the interstellar matter (secondary production)There might be signals from additional (astrophysical or exotic)There might be signals from additional (astrophysical or exotic)

sources

• Different measurements provide complementary information of the p p yorigin, acceleration and propagation of cosmic rays

All available data must be interpreted in a coherent scenario

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Fermi_PIC2009.pptIntroduction (2):Introduction (2):Positron and Antiproton Fraction: 2008Positron and Antiproton Fraction: 2008--0909

PAMELA positron and antiprotonNature 458, 607 (2009)PRL 102, 051101 (2009)PRL 102, 051101 (2009)

1 GeV 10 100

• Antiproton fraction consistent with secondary production• Anomalous rise in the positron fraction above 10 GeV• Several different viable interpretations (>200 papers over the last year)

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See also Nature 456, 362 (2008) and PRL 101, 261104 (2008) for pre-Fermi CRE spectrum by ATIC and HESS.

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Fermi-LAT Capability for CR Electrons• Candidate electrons pass through 12.5 X0 on average ( Tracker and Calorimeter added together)

• Simulated residual hadron contamination (5-21% increasing with the ( genergy) is deducted from resulting flux of electron candidates

• Effective geometric factor (Gf) exceeds 2.5 [m2 sr] for 30 GeV to 200 GeV, and decreases to ~1 [m2 sr] at 1 TeV. Gf times exposure has already reached [ ] f p yseveral x 107 [m2 sr s]. (very high statistics)

• Full power of all LAT subsystems is in use: Tracker, Calorimeter and ACD act together

Geometric Factor (Gf)

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Residual hadroncontamination 20 GeV 100 GeV 1 TeV

Fermi_PIC2009.ppt

Fermi-LAT Electron Spectrum

Abdo et al. Phys. Rev. Let. 102, 181101 (2009)181101 (2009)

Cited 38 times within a month

APS Viewpoint

Harder spectrum p(spectral index: -3.04) than previously thought

Total statistics collected for 6 months of Fermi LAT observations4 5 million candidate electrons abo e 20 GeV

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~4.5 million candidate electrons above 20 GeV> 400 candidate electrons in last energy bin (770-1000 GeV)

Fermi_PIC2009.ppt

Implication from Fermi-LAT CRE (1)

Old “conventional” CRE Modelγ0=2.54

for detail, seeD. Grasso et al. arXiv:0905.0636 (accepted by Astroparticle

)Physics)

New “conventional” CRE modelsγ0=2.42 γ0=2.33

Fermi CRE spectrum can be reproduced by the “conventional” Galactic cosmic-ray source model, with harder injection spectral index (-2.42) than in a pre-Fermi conventional model (-2.54). All that within our current

t i ti b th t ti ti l d t ti

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uncertainties, both statistical and systematic.

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Implication from Fermi-LAT CRE (2)Now include recent PAMELA result on positron fraction• Qualitative approach: the harder primary CRE spectrum is, the steeper secondary-to-primary e+/e- ratio should be. PAMELA shows the opposite.

New “conventional” CRE models

Old “conventional” CRE Model

Precise Fermi measurement increases the discrepancy between a

Tsunefumi Mizuno 25

purely secondary origin for positrons, and the positron fraction measured by PAMELA.

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Implication from Fermi-LAT CRE (3)It is becoming clear that we are dealing with at least 3 distinct origins of HE e-/e+

Uniformly distributed distant sources, likely SNRs.Unavoidable e+e- production by CRs and the ISM “conventional” sourcesAnd those that create positron excess at high energies. Nearby (d<1 kpc) and Mature (104 - 106 yr)

pulsars?

An example of the fit to both Fermi and PAMELA data with Monogem and Gemingawith a nominal choice for the e+/e injection parameter (blue lines) Works well

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with a nominal choice for the e+/e- injection parameter (blue lines). Works well.(Discrepancy in positron fraction in low energy can be understood as the charge-sign effect of solar modulation)

Fermi_PIC2009.ppt

Dark Matter InterpretationDark Matter InterpretationWhat said about pulsars is applicable to dark matter as sources of e- and e+.

PAMELA and Fermi data tighten the DM constraints, favoring pure e+e-, lepto-philic, or super-heavy DM models.

likely excludedpreferred likely excludedpreferred

10-22

σv [cm3/s]10-19

pure e+e- Models lepto-philic Super-heavy DM

10-24 10-21

100 GeV 1 TeVDM mass

10-26 10-23

• We need local sources (astrophysical or exotic). The origin is still unclear but is strongly constrained by Fermi data (+ others)

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but is strongly constrained by Fermi data (+ others)• More results from Fermi-LAT are coming. Extending energy range to 5 GeV – 2 TeV and searching for the CRE anisotropy at a 1 % level.

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Hi hli ht f F i’ 1Hi hli ht f F i’ 1stst (3)(3)Highlights from Fermi’s 1Highlights from Fermi’s 1stst year (3): year (3): Galactic Diffuse GammaGalactic Diffuse Gamma--ray ray yyEmission (Indirect Probe of Emission (Indirect Probe of

Galactic CRs)Galactic CRs)Galactic CRs)Galactic CRs)

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Cosmic-Rays OverviewV. Hess, 1912• Discovered by V. Hess in 1912• Globally power-law spectrum with some structures (knee and ankle)

hint of the originL d it ( 1 V 3) bl t U d U• Large energy density (~1 eV cm-3): comparable to UB and Urad

• UHECRs : not covered by this talk in detailsmall scale anisotropy

V)-1

1 particle/m2/sec

Galactic

x (m

2sr

s G

eV

KneeG or EG?

Flux 1 particle /m2/yr

AnkleAuger Collaboration Sci 318 938 (2007)

Extragalactic

Tsunefumi Mizuno 29Energy (eV)

1 particle/km2/yrAuger Collaboration, Sci. 318, 938 (2007)

18/27 events > 5.6 x 1019 eV correlate with nearby AGNs. See also arXiv:0906.2347

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CRs and Galactic Diffuse GammaCRs and Galactic Diffuse Gamma--RaysRaysHE γ-rays are produced via interactions between Galactic cosmic-rays (CRs) and the interstellar medium (or interstellar radiation field)

(CR Accelerator) (Interstellar space) (Observer)

X,γISMSNR SNR

RX J1713RX J1713--39463946Chandra Suzaku

(CR Accelerator) (Interstellar space) (Observer)

e+-

diffusiondiffusionHESS

B

PP

Chandra, Suzaku, Radio telescopes

ICISRFdiffusiondiffusionenergy losses energy losses

reaccelerationreaccelerationconvectionconvection

etcetcπ0Pulsar,

μ-QSO

HeHeCNOCNO

HESS Fermi

gase +-

π+-etc.etc. HESS, Fermigas

π

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A powerful probe to study CRs in distant locations

Fermi_PIC2009.pptOutstanding Question: Outstanding Question: EGRET GeV ExcessEGRET GeV Excess

• EGRET observations showed excess emission > 1 GeV everywhere in the sky when

|b|=6°-10°

everywhere in the sky when compared with models based on directly measured CR spectra

Potential explanations0.1 1 10 GeV

|b| 2° 6°• Potential explanationsUnexpectedly large variations in

cosmic-ray spectra over GalaxyDark Matter

|b|=2°-6°

Dark MatterUnresolved sources (pulsars,

SNRs, …)Instrumental

|b|<=2°Instrumental

• Fermi-LAT is able to confirm or deny this phenomena

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deny this phenomena

Hunter et al. 1997~100% difference above 1 GeV

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Intermediate Latitude Region seen by LATIntermediate Latitude Region seen by LAT

|b|=10°-20°

EGRETLAT

0 1 1 10 GeVAbdo et al. submitted to PRLPorter et al 2009 (arXiv:0907 0294) 0.1 1 10 GeV

• |b|=10°-20°: avoid Gal. plane but still have high statistics• EGRET spectrum extracted for the same region

Porter et al. 2009 (arXiv:0907.0294)

EGRET spectrum extracted for the same region

• LAT spectrum is significantly softer and does not confirm th EGRET G V

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the EGRET GeV excess • Strongly constrains the DM interpretation

Fermi_PIC2009.ppt

Probing CRs using GammaProbing CRs using Gamma--rays from ISMrays from ISM

• Correlation with gas column density reveals the CR spectrumMethod go back to SAS-2/COS-B era

• Fermi-LAT’s high performance + CR propagation model (e.g. GALPROP) to predict IC

Sensitivity significantly improved

ISM(e.g., LAB HI survey) Gamma-ray intensity

(F i LAT d t )( g , y)

(http://www.astro.uni-bonn.de/~webaiub/english/tools_labsurvey.php) (Fermi LAT data)

High latitude region:Detailed study of local CRs (most of the gas is close to solar system)

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Detailed study of local CRs (most of the gas is close to solar system)Galactic plane:

CR gradient in the Galaxy (need to resolve point sources)

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Accurate Measurements of Local CRsAccurate Measurements of Local CRsMid-high lat. region in 3rd quadrant:

• small contamination of IC and molecular gas• correlate γ-ray intensity and HI• correlate γ-ray intensity and HI gas column densityAbdo et al. 2009, accepeted by ApJ(arXiv:0908.1171) contact author: TM

LAT data• Best quality γ-ray spectrum in 100 MeV-10 GeV (T = 1-100 GeV)

nucleon-nucleon

model from the LIS100 MeV-10 GeV (Tp = 1-100 GeV)

• Agree with the model prediction from the local interstellar

electron-

nucleon-nucleon

• Prove that local CR nuclei spectra are close to those

spectrum (LIS)

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bremsstrahlungp

directly measured at the Earth

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CR Distribution in GalaxyCR Distribution in Galaxy

SNR distribution(C & Bh tt h 1998)

Pulsar distribution(Lorimer 2004)

• CR distribution is a key to understand their origin and propagation• distribution of SNRs not well measured

CR source distribution from γ-rays(Strong & Mattox 1996)

(Case & Bhattacharya 1998)• Previous Gamma-ray data suggests a flatter distribution than SNR/pulsar distributions (e.g., Strong et al. 2004)

0 5 10 15 kpcsun

Gal.Center

• Fermi-LAT is able to map out CR distributions in the Galaxy with unprecedented accuracy

Inner Galaxy

with unprecedented accuracy• Work in progress. (arXiv:0907.0304 and arXiv:0907.0312)

Tsunefumi Mizuno 35

OuterGalaxy

Fermi_PIC2009.ppt

Highlights from Fermi’s results (4): Highlights from Fermi’s results (4): Selected Galactic and ExtragalacticSelected Galactic and ExtragalacticSelected Galactic and Extragalactic Selected Galactic and Extragalactic Objects as a Key to Understand CRsObjects as a Key to Understand CRs

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Fermi_PIC2009.pptIntroduction: Introduction: γγ--ray objects seen ray objects seen by the LATby the LAT

Class NumberFSRQ 64 • Variety of objects in the LAT BL Lac 46Radio galaxy 2Other blazar 9

bright source list (Abdo et al. ApJS 183, 46, 2009)• >=200 sources. More than 80%

Other blazar 9Radio/X-ray pulsar 15LAT γ-ray pulsar 15

are identified (EGRET:~30%)

• Here I will pickup SNRs, LMC and Blazars and briefly discussγ y p

HMXB 2Globular cluster 1

and Blazars and briefly discuss their implications for CRs.

• Many other very importantLMC 1Special cases (SNRs PWNe)

13

Many other very important objects and topics will not be discussed. (See LAT publications, please)

Tsunefumi Mizuno 37

(SNRs, PWNe)Unidentified 37

p , p )

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Fermi LAT Study on SNRsFermi LAT Study on SNRs

• SNRs are the most favored explanations for the origin of Galactic CRs.Diffusive shock acceleration in SNR shell. Sufficient to supply CRs up to knee.

• Significant progress in recent years in keV and TeV observation of young SNRs.• Key issues to be addressed by Fermi-LAT:

Searching for pion signatures & measuring total energy content per SNR

• Several possible associations to SNRs in the LAT bright source list includingSeveral possible associations to SNRs in the LAT bright source list including

W44: (T. Tanaka et al. proc. ICRC 2009) Middle age (2000 yr), Mixed Morphology, 3 kpcInteractions with Molecular CloudEGRETFermi-LAT: (0FGL J1855.9+0126: 3 month data yield 39σ)

W51C: (Y. Uchiyama et al. proc. ICRC 2009)Middle age (20000 yr), 6 kpcInteractions with MC

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HESS (Fiasson et al. 2009, no spectrum)Fermi-LAT: (0FGL J1923.0+1411: 3 month data yield 23σ)

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W51C: The Fermi Source is “Extended”W51C: The Fermi Source is “Extended”

• Mean surface brightness (2-8 GeV) as a function of distance from the SNR center vs. Fermi-LAT PSF => Spatially extended

Bl k t ROSAT X (0 1 2 4 k V)Black contours: ROSAT X-ray (0.1-2.4 keV)Green contours: VLA 1.4 GHzColor: Fermi-LAT count map (2-8 GeV)

0 6 degR

0.6 deg

Tsunefumi Mizuno 39

(Note) PSF of Fermi LAT depends heavily on energy. The PSF shape above is obtained by taking account of the energy distribution (not presented).

Fermi_PIC2009.ppt

Spatial Extent of W44Spatial Extent of W44

Smoothed Count Map (>1 GeV) Profile along the rectangleContributions form the diffuse backgrounds

and nearby sources are subtracted

• For both W44 and W51C, gamma-rays are spatially “extended” & Black Cross: Pulsar (PSR B1853+01) location

Red: Observed CountsBlack: Expected Profile for a Point Source

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, g y p ypositionally coincident with SNRs. The luminosity is found to be very large.• Spectral analysis will be presented in a refereed journal

Fermi_PIC2009.ppt

Local Group GalaxiesLocal Group Galaxies

• LMC detection: CR density is inferred to be similar to MW• SMC non-detection: CR density is smaller than in the MW

EGRET Observation Summary:

• M31 non-detection: has to have smaller CR density than the MW (size M31>MW)

• First direct evidence that CRs (E<Eknee) are Galactic and not universal• Key issues not fully addressed yety y y

CR propagation in each Galaxydetailed comparison of CR densities

among galaxies

Tsunefumi Mizuno 41

Fermi_PIC2009.ppt

FermiFermi--LAT Resolved the LMCLAT Resolved the LMC

CRATES J060106-703606

30 Doradus

Gal. longitude

• 161 days of survey data, ~ 1300 events above 100 MeV

Gal. latitude

• Gamma-ray is clearly extended, with the maximum consistent with the massive star-forming region 30 Doradus

Dust map (SFD)

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adaptively smoothed 100 MeV - 10 GeV counts map (s.n.r. = 5)

Detailed study of spatial and energy distribution is in progress

Fermi_PIC2009.ppt

LAT Bright AGN Sample (LBAS)• 125 non-pulsar sources at |b|>10o

• 106 high-confidence (P>90%) associations with AGNs11 lower-confidence (40%<P<90%) associations( % %)9 unidentified (3EG: 96/181 at |b|>10o)

Only ~30% of the bright Fermi AGNs were 58 FSRQ42 BL Lac

detected by EGRET. The Sky changes! 4 of Uncertain class2 Radio Galaxies

Tsunefumi Mizuno 43

Abdo et al. ApJ 700, 597 (2009)

Fermi_PIC2009.ppt

Population of the LAT AGNsPopulation of the LAT AGNs• 42 BL Lacs and 58 FSRQs (EGRET: 14 and 46)• BL Lac has harder spectrum than FSRQ (1.99 +/- 0.22 vs. 2.40 +/- 0.17)• V/Vmax test (Schmidt 1968) indicates the positive evolution for FSRQ

(more sources or brighter sources at earlier time)(more sources or brighter sources at earlier time)• Local emissivity

ℓBL ≥ 1031 W Mpc-3, ℓFSRQ ≈ 1030 (ℓUHECR ≈ 3x1029; Waxman & Bahcall 1999)BL Lacs are favored as the origin of UHECRs (if AGNs are the sources)

3x1029 W Mpc-3S. Razzaque, J. Finke

and C. Dermer

Tsunefumi Mizuno 44

p

Fermi_PIC2009.ppt

SummarySummary• Presented a very biased summary of gamma-ray particle astrophysics

• Long history of more than 40 years. Significant progresses in recent ears b Air Cherenko Telescopes and Fermiyears by Air Cherenkov Telescopes and Fermi.

• Fermi view of GRBs:>240 GRBs, 9 detected by LAT (as of June 2009)240 GRBs, 9 detected by LAT (as of June 2009)GRB080916C & GRB090510

strongly constrains the bulk Lorentz factor, Lorentz invariance, etc..• CR electrons by Fermi + PAMELA and other data.

L l i dLocal sources are required. Nearby mature pulsars. Constrains on DM scenario

• Diffuse gamma-rays as a probe of Galactic CRsnon-GeV-excess Local CRs close to those measured at the Earchnon GeV excess. Local CRs close to those measured at the Earch.Is able to map out CR distribution in the Galaxy

• Found extended sources positionally associated with SNR. Resolved LMC for the first time. BL Lacs are favored (than FSRQs) as the origin

Tsunefumi Mizuno 45

of UHECR.

Thank you for your attention!

Fermi_PIC2009.ppt

Backup SlidesBackup SlidesBackup SlidesBackup Slides

Tsunefumi Mizuno 46

Fermi_PIC2009.ppt

GRB 080916C SpectrumGRB 080916C Spectrum• No conclusive evidence of extra HE component

– Probability of no extra component is ~1%– Effect of EBL

Time bin ‘d’

• HE absorption• Transparency:

0.03–1.0 BandGBM NaI

LAT0 03 0(model dependent)

• Single Band-functiondominant for 6 decades Band function

Band + power law

GBM NaI

GBM BGO

of energy band• Lack of prominent

SSC component implies– High magnetic field

• εe/εB 0.1– Epeak,SSC 10 GeV (γe 100) SSCSSC

EEp,SSCp,SSCEEp,synp,syn γγee

22ννFFνν

~ε~ε /ε/ε

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peak,SSC (γe )synchrotron synchrotron

SSCSSC

νν

~ε~εee/ε/εBB

Fermi_PIC2009.ppt

FOM for CRE MeasurementFOM for CRE MeasurementExposure factor (effectively) determines the # of counts

Ef(E) = Gf(E)*Tobs

L B ldi iL. Baldini

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Fermi_PIC2009.ppt

LAT LAT vsvs prepre--Fermi ModelFermi Model• Compare with a CR propagation model prediction based on pre-F i CR d t (St t l 2004 LATFermi CR data (Strong et al. 2004, Porter et al. 2008)π0-decay, e-Brems, Inverse Compton

LATmodel total

π0-decay

• Source and isotropic (w/ residual BG) component come from fitting the data to the sky above 30 deg

ICe-Bremsthe data to the sky above 30 deg latitude with model fixed • Although there is a uniform

b th d l d t iexcess above the model, data is reasonably reproduced by the model

Th d l i f l id i i i i i

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The model is successful considering it is a priori pre-Fermi model

Fermi_PIC2009.ppt

Correlation with the HI Column DensityCorrelation with the HI Column Density• Mask point sources (52 total) and subtract the residual point source contributions. Also subtract the IC contributions.

C l ti f 100 M V t 10 G V Th l i th• Correlation from 100 MeV to 10 GeV. The slope gives the γ-ray emissivity spectrum of local HI gas produced through interactions with CRs.

(error bars are statistical only)

sity

1 6-2 3 GeV400-560 MeV

400-566 MeV

HI column density (1020 cm-2)

ay In

tens

1.6-2.3 GeV

E2x

γ-ra

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HI column density (1020 cm-2)

Fermi_PIC2009.ppt

Fermi View on W51C RegionFermi View on W51C RegionBlack contours: ROSAT X-ray (0.1-2.4 keV)Green contours: VLA 1.4 GHzColor: Fermi-LAT count map (2-8 GeV)

X-ray:• Thermal emission by shock-heated plasma (kT=0.2 keV)• Central region due to cloud evapolation?R diRadio:• Peaks are HII region• Synchrotron radiation is well matched with thermal X-rays

G V

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GeV gamma-ray:• Origin?• Very high luminosity (~4 x 1035 erg/s) using 6 kpc

Fermi_PIC2009.ppt

FermiFermi--LAT Image of W44LAT Image of W44Fermi-LAT Smoothed Count Map (Front Evnets; 2-10 GeVBlack cross: location of PSR B1853+01

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Spatially Extended??