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Diffuse Gamma-Ray Emission. Su Yang 2010.1.19. Telescopes Examples Our work. VERITAS (Very Energetic Radiation Imaging Telescope Array System): 4*12*345. angular resolution: 0.1d@1TeV, 0.14d@200 GeV (68% containment radius) energy range: 100 GeV to >30 TeV
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Diffuse Gamma-Ray Emission Su Yang 2010.1.19
Telescopes • Examples • Our work
VERITAS (Very Energetic Radiation Imaging Telescope Array System): 4*12*345 • angular resolution: 0.1d@1TeV, 0.14d@200 GeV (68% containment radius) • energy range: 100 GeV to >30 TeV • energy resolution: 15% at 1 TeV • source location accuracy: 50’’ http://veritas.sao.arizona.edu/
H.E.S.S. (High Energy Stereoscopic System): 4*13*382 • energy resolution: 15% (Index~0.1; Flux~20%) • energy range: 0.1-10 TeV • PSF: 0.03/0.06d • FOV: 5d http://www.mpi-hd.mpg.de/hfm/HESS/
VERITAS Telescopes Help Solve 100-Year-Old Mystery;The Origin of CRs, Nature, 2009 • CR density (M82)~500*CR density (our Galaxy): SNe & Winds from massive stars Chandra;Spitzer; Hubble; Web Source
SNR G106.3+2.7 (60*24’; D~0.8kpc; Boomerang) Fermi (PSR J2229+6114) 3EG J2227+6122 0.4d Radio CO (-6, -4 km/s) Acciari et al. 2009, arXiv0911.4695
IC443: 1.5kpc, 45’; CXOU J061705.3+222127; (VER J0616.9+2230 ~ Magic J0616+225 ~ Milagro; 0FGL J0617.4+2234 ~ 3EG J0617+2238; ) Radio EGRET Fermi Magic OH PWN CO (-20,20km/s) Acciari et al. 2009, ApJ, 698:L133-L137
IC: L(0.3-2.0TeV)~4E32 erg/s E (rotation)~1-50E36 erg/s • Synchrotron cooling: Time (E)~ 1.3E7 (B/uG)-2 (E/GeV)-1 kyr E(electron)~20TeV, B~5uG Time~30 kyr (Abdo et al., 2010, B(Cas A)>=0.1mG) • Hadronic CRs Particles were accelerated prior to the shock hitting the MC? Or an energy-dependent rate of diffusion of CRs out of the MC? Acciari et al. 2009, ApJ, 698:L133-L137
VERITAS (Northern Sky) AGN, BIN, PWN, starburst galaxy, SNR, UNID Ong et al. 2009, arxiv0912.5355 +Web Source VERITAS HESS EGRET+GLAST
Fermi (GLAST: Gamma-ray Large Area Space Telescope): 2008-06-11 >9000 sources 271 sources
Dark Matter? Variations of the Galaxy’s CR spectra? Unresolved point sources? Instrumental effects? 1-10GeV excess? Abdo et al. 2009, arXiv0912.0973
The DGE (diffuse Galactic emission): CRs (protons, electrons) the ISM (Pi0-decay + bremsstrahlung), and radiation field (IC); 10-15% Abdo et al. 2009, arXiv0912.0973
(Abdo et al., 2010, arXiv:1001.1419; B(Cas A)>=0.1mG)
(Abdo et al., 2010, arXiv:1001.1419; B(Cas A)>=0.1mG) Leptonic model Hadronic model
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