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Supernova and GRB remnants and their GeV-TeV g -ray emission. Kunihito Ioka (KEK) Peter Mészáros (IGC, Penn State). 1. GRB/Hypernova remnants ~ TeV unID sources 2. A new mechanism for TeV g : Radio Isotope decay. Contents. TeV unidentified (TeV unID) sources
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Supernova and GRB remnantsand their GeV-TeV g-ray emission Kunihito Ioka (KEK) Peter Mészáros (IGC, Penn State) 1. GRB/Hypernova remnants ~ TeV unID sources 2. A new mechanism for TeV g: Radio Isotope decay
Contents TeV unidentified (TeV unID) sources No counterpart, Origin unknown Gamma-Ray Burst (GRB) GRB-Supernova/Hypernova GRB/Hypernova remnant-TeV unID 1. p0 decay: Nobs(HNR)~Nobs(SNR) 2. b decay + e-Inverse Compton 3. Radio isotope (RI) decay
Multi-wavelength sky Radio IR Opt X g New wavelength⇒New sources (GRB, pulsar, …)
Increasing TeV sources “Kifune plot” Jim Hinton, rapporteurtalk, ICRC 2007 Most abundant category: unID! No clear counterparts at other wavelengths
Observed properties TeV unID Disk ⇒ Galactic origin Aha+ 06 Extended
TeV g-ray Leptonic process (e with 10-100TeV) Synchrotron⇒X Inverse Compton⇒g Electron acceleration Synchrotron (X) Magnetic Field Inverse Compton (g) CMBg Hadronic process (p with 10-100TeV) pp⇒p0 decay⇒2g Proton acceleration p0 2g Nucleus p+
SNR Koyama+ 05 Bamba+ 03 CR acceleration at SN shock Most likely Galactic CR origin Also likely TeV g sources Hwang+ 04 Aha+ 04
Suzakuupper limit Suzaku⇒Strong X-ray upper limit FTeV/FX>50 ⇒ Leptonic × Hadronic ○ ⇒ Young SNR × TeV g X-ray Matsumoto+ 07 Bamba+ 07
Old SNR? In old SNRs, emax,electron is low butp0g flux~const ⇒ FTeV/FX>100 Yamazaki+ 06 TeV X But, Rate~1/100yr⇒103 SNR ⇔ 10 unID
GRB = Rare SN Luminosity The most luminous objects~1051erg/s >msec Afterglow GRB X Opt Radio Redshift ~1000 events/yr isotropic ~200 keV, nonthermal 10-3s~103s : Short, Long SN ~1day Time
Standard model optically thick gg→e+e- Internal shock SN? ? ISM G>100 External shock Central Engine 光度 Afterglow Kinetic energy ↓ Shock dissipation GRB 時間
GRB-SN Hjorth+(03) Afterglow Light curve Type Ic spectrum Bloom+(99) ⇒ GRB is associated with SN Ibc
Collapsar Jet breaks out the massive stellar envelope
GRB/Hypernova Hypernove (hyper-energetic SNe) occur more frequently than GRBs EHN~1052erg RSN~1/100yr RHN~1/104yr RGRB~1/105yr tage~105yr ⇒ NHN~10~NunID Nomoto+
Old GRB/HN remnant g-ray Flux for pp→p0→2g Just by scaling the SNR calculations ~FunID CR energy~1051erg~10%x1052erg Flux: t-independent ⇒Old ones are dominated ⇒leptonic emission is weak (low emax,e) ⇒ unID Number Size R~1/104yr tage~105yr ⇒ NHN~10~NunID
Observed number ratio Observed #(HNR)~Observed #(SNR) ① ~10times energy ⇒ dmax∝E1/2 ② Sensitivity to extended sources∝(size)∝d-1 ⇒ dmax∝E ⇒ Volume∝dmax2∝E2 Observable SNRs are nearby ⇒ Size is too large?
GRB jet-Cosmic Ray SN shock Hillas diagram B GRB E<ZeBR Internal shock External shock also accelerate cosmic ray R RGRB~1/105yr ⇒ NGRB~1 but recent obs. suggest RGRB w/ slow jet~1/104yr~RHN
GRB remnant (GRBR) Loeb & Perna 98 Wick, Dermer & Atoyan 04 Dermer & Atoyan 06 After non-rela ⇒ Jet→Sphere ⇒ GRBR~SNR hydrodynamically (cf., R~E1/5) Metal distribution could be different Ayal & Piran 01
1. p0 decay HESS J1301-631 SNR All Atoyan, Buckley & Krawczynski 06 Relativistic souces ⇒ less particle @ low E ⇒ Low GeV & Radio emission
2. b decay – e-IC ep~1016g7eV tdecay~900s pg→np+ g (CMB, …) Energy fraction of TeV g KI, Kobayashi & Mészáros 04
Unique morphology KI, Kobayashi & Mészáros 04 W49B SNR Elongated emission outside SNR Age/Energy dependent profile Less e @ low E Dim @GeV & radio
Candidate? Aha+ 06
3. Radio isotope (RI) decay 56Ni ⇐ SN light curve 1998bw: M(56Ni)~0.4M◉ ~2MeV Could be shock-accelerated before decay (by reverse shock?) No need for target g and matter
SN light & RI decay NS/BH Nomoto+07 56Ni, 56Co decay ⇒SN light curve Complete Si burning⇒56Ni Fall back to central BH/NS
Fe(56Ni) O Woosley & Zhang 07 Mazzali+05
RI decay model 56Co case 56Co energy GRB jet OK SNR disappears Energy fraction of TeV g ~energetic GRB
Spectrum tdecay~106g6yr eg~TeVg6 t nFn n(2-p)-1 Exp. cutoff Already decayed Now decaying ~GeV n ~TeV
RI model spectrum 105yr p-2nd e+ Radio X
Fe ? Auger Depth of air shower maximum
Photo-disintegration Murase,KI+08 Wang, Razzaque & Mészáros 07 Ni/Co/Fe can survive photo-disintegration (⇔ Fe UHECR implied by Auger Xmax)
Model identificaion Neutrino g Morphology p0 No n (Already decayed) b RI
Summary TeV unID sources Dominant in TeV sky, Origin unknown Old GRB/Hypernova remnant Nobs(HNR)~Nobs(SNR) SNR may be more nearby and extended BH in unID? A new mechanism for g-ray production Decay of Accelerated Radio Isotope (RI) No need for target matter or photon