Galactic Diffuse Gamma-Ray EmissionGLAST Japan Workshop

November 24-25, 2006

Tuneyoshi KAMAE (SLAC/KIPAC, Stanford University)

1. Introduction:• Status of EGRET γ-ray diffuse emission mdeling• What Integral see in hard X-ray band• Diffuse emission seen in the X-ray band

2. New anaysis technologies for GLAST era we are working on• Correct p-p int. modeling for secondary particles (pub and to be pub)• Correct analysis of low-energy EGRET diffuse emission (to be pub) • 3D ISM distr. by Nakanishi and Sofue for H2 and HI (pub and to be pub)• Modeling of non-Fermi acceleration senario (in progress)

3. Preliminary results• Possible new interpretation of EGRET γ-ray diffuse emission (in progress)• Clarification of “unidentified sources”: Suzaku, Nanten, GLAST, NuStar

Cosmic Ray Propagation and Interaction- Interplay among sources(SNRs), propagation, targets(H2,HI, ISRF) -

From Strong and Moskalenko

GALPROP: γ-Ray Spectrum- A parameter set to explain EGRET γ-ray spectrum -

IC: uncertainty in •e−/e+

•ISRF

e−/e+: •2-3 time the local flux•spectral shape adjusted

π0: proton flux•~2 times higher than LIS

GALPROP: Longitude Distribution- Optimized to explain EGRET γ-ray map -

30-50MeV 50-70MeV 70-100MeV

100-150MeV 150-300MeV 500-1000MeV

Glon distribution for |Glat|<5.5 deg Look all similar: tracer for H2 and HI?

GALPROP: Latitude Distribution- Optimized to explain EGRET γ-ray map -

30-50MeV 50-70MeV 70-100MeV

100-150MeV 150-300MeV 500-1000MeV

Glat distribution for |Glon|<30.5 deg Look all similar: tracer for H2 and HI?

Observation in Hard X-ray Band- Ginga, ASCA, Integral, Suzaku -

Exposure map of Integral Has not survey the entire ridge

Observation in Hard X-ray Band- Integral -

Enhancement in |Glon|<10 deg

Deconvolution of EGRET’s PSF- Why essential -

True directionof γ-ray

Reconstructed direction of γ-ray

Angular dependence of “exposure” (~FOV)

True exposure

Assumed exposure

EGRET PSF for E<150MeV

EGRET FOV

High latitude flux is systematically over estimated by up to 20-30%

Need sharper image for detailed analyses

Kamae, in prep

Deconvolution of EGRET PSF- PSF Representation on Glon-Glat Map is Glat-dependent -

Index2.2 at Glat=0.0

Index2.2 at Glat=+/-22.0 Index2.2 at Glat=+/-26.0

Angular Response Matrix Based on EgretPsf- Building 3600x3600 Matrix for E0-E9-

Deconvolution of EGRET’s PSF- Ideal and Poisson noise dominated cases -

True Latitude Distribution in Low Energy- PSF deconvolved maps –

l=-74~-34 l=-30~-30 l=34~-74

E(MeV)=30-50(brn), 50-70(mgt), 70-100(grn), 100-150(blu), 150-300(blk)

Proton-Proton Interaction Modeling- Cross-sections -

Total cross-section

Total inelastic

Non-diffractive

Diffractive process

Elastic cross-section

Delta(1232) excitation

Reson(1600) excitation Kamae, Abe, Koi (ApJ 05)Kamae, Karlsson, Mizuno, Koi, Abe (to be submitted to ApJ)

Proton-Proton Interaction Modeling- Low energy cross-sections -

Total inelastic

Non-diffractive

Diffractive process

Delta(1232) excitationReson(1600) excitation

Experimental data on total inelastic

Model vs Exp. Data- Resonance region -

Tp=0.65GeV Tp=0.68GeV Tp=2.0GeV

Model vs Exp. Data- Pi-0 multiplicity -

Total inelastic

Non-diffractive

Diffractive process

Delta(1232)Reson(1600)

Experimental data

Predictions of Our Paramerized Model- Harder secondary spctr expected -

γ-ray spectrum will be harder than that of the incident proton

Galprop withbuilt-in pp model

Galprop withour pp model

γ-ray spectrumindex=1.95

γ-ray spectrum for power-law proton of index=2.0

Kamae, Abe, Koi (ApJ 05)Kamae, Karlsson, Mizuno, Koi, Abe (to be submitted to ApJ)

Predictions of Our Param. Model- Secondaries positron dominates over electrons -

Positron

Electron

Spectrum vs. Viewing Angle- Important for mom-dependent diffusion -

Spiral arm structure we now know is different from that by Georgelin & Georgelin ‘79

Perseus

Local

Sagittarius-C

arina

Norma

Scutum-Crux

HI cloud and armsNakanishi & Sofue ‘05

H2 cloud and armsNakanishi & Sofue ‘05

Bar structure

Density too high?

Matter Distribution in 3D- H2 and HI 3D distr. by Nakanishi and Sofue -

Matter Distribution- H2 and HI projected column density -

Matter Distribution- H2 and HI in the Galactic disk (|Glat|<4deg) -

H2+HI

H2

HI

Correction for missing section

Correction for missing section

Something wrong?

EGRET Intensity Profile along Gal Long. (1/4)

EGRET Intensity Profile along Gal Long. (2/4)

EGRET Intensity Profile along Gal Long. (3/4)

EGRET Intensity Profile along Gal Long. (4/4)

Acceleration at SNR and Galactic CR Spectrum

Berezhko &Elliison 1999

Not power law spectrum at the shockNaïve calculation by Yamasaki (‘97)

Heating and instabilitybuild-up

Run-away turbulanceδB/B >> 1

Acceleration(Non Fermi-type?)

Mom. dependent escape

Conclusion

• New tools and new modeling bring up new physics.• Multiwavelengthe collaboration is norm. From Japnese

perspective:üGLASTüSuzaku (hard X-ray)üNanten and its upgrade (molecular clouds)üSubaru and smaller telescopes (GRB followup)üCangaroo (TeV γ-ray)

• Resolution of diffuse Galactic emission and origin of CR• Understanding acceleration mech. and discovery (or

upper limit) of dark-matter will follow

Ec=5GeV

E-2.7

E-3.7