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Ground-based Cherenkov: VERITAS HESS Cangaroo III MAGIC  MAGIC-2 Milagro

Gamma Ray Sources Chuck Dermer Naval Research Laboratory Washington, DC USA TAUP 2007, Sendai, Japan, September 2007. Topics in Astroparticle and Underground Physics. Ongoing revolution in our understanding of g -ray sources. TeV astronomy. GeV astronomy. Ground-based Cherenkov: VERITAS

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Ground-based Cherenkov: VERITAS HESS Cangaroo III MAGIC  MAGIC-2 Milagro

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  1. Gamma Ray SourcesChuck DermerNaval Research LaboratoryWashington, DC USATAUP 2007, Sendai, Japan, September 2007 Topics in Astroparticle and Underground Physics Ongoing revolution in our understanding of g-ray sources TeV astronomy GeV astronomy • Ground-based Cherenkov: • VERITAS • HESS • Cangaroo III • MAGIC  MAGIC-2 • Milagro • Space-based: • EGRET  GLAST • AGILE + multi-wavelength/ multi-messenger information (talk by W. Hoffman) focus on GeV and extragalactic sources

  2. The Gamma-Ray Sky Diffuse/unresolved emissions (Quasi)-quiescent radiations Pulsing sources Flaring sources Bursting sources

  3. EGRET Detector Energetic Gamma Ray Experiment Telescope on the Compton Gamma Ray Observatory • Spark Chamber • Energy range: ~100 MeV – 5 GeV • Pointing Instrument (psf ~ 5.7° at 100 MeV) • Two week observation: ~106 sec • Field-of-view: ~1/24th of the Full Sky • Two-week detection threshold • 1510-8 ph(>100 MeV) cm-2 s-1 • (high-latitude sources; background limited) • nFn Threshold energy flux: 10-10 ergs cm-2 s-1 Flew 1991 -- 2000

  4. GLAST Detector Gamma Ray Large Area Space Telescope Large Area Telescope + GLAST Burst Monitor • LAT Tracker • Energy range: ~ 50 MeV – 100 GeV • Scanning Instrument (psf ~ 3.5° at 100 MeV) • Views whole sky every 3 hours • Field-of-view: ~1/5th of the Full Sky • One year detection threshold • 0.410-8 ph(>100 MeV) cm-2 s-1 • (high-latitude sources; background limited) • nFn threshold energy flux: 3 10-12 ergs cm-2 s-1 Launch: February 2008 (talk by C. Cecchi)

  5. EGRET (> 100 MeV) All-Sky Map • Requires background cosmic-ray/gas model to find g-ray sources

  6. (Hartman et al. 1999) (271 Sources, plus 5 GRBs) Catalog of Established High Energy (> 100 MeV) Gamma-Ray Sources (66/27 hi/low confidenceAGNs) GRBs + Radio galaxy (Cen A) High mass binaries/microquasars

  7. Revised EGRET Catalog Before: After: • 107 3EG sources not confirmed • most Gould Belt sources • 32 new sources from 9-year data • GeV/TeV irradiated cloud "sources" Casandjian & Grenier ‘07

  8. g-Ray Supernova Remnants • No unambiguous identification of a SNR with EGRET • SNR maps with HESS • RX J1713.7-3946 • Vela Jr • RCW 86 • Cosmic Ray Origin Problem • g rays from Compton-scattered CMB • g rays from CR p + p,N  p0 • Detection of p0 bump with GLAST Aharonian et al. 2007

  9. Normal, Starburst and IR Luminous Galaxies • Detection of LMC with EGRET • fg= 19  10-8 ph(>100 MeV) cm-2 s-1 • (Sreekumar et al.1992) • spectral shape consistent with that expected from cosmic ray interactions with matter • Scale to local galaxies (SMC, Andromeda) • Starburst Galaxies (M82, NGC 253;  3 Mpc) • IR Luminous Galaxies (Arp 220;  72 Mpc) (Torres 2004)

  10. Clusters of Galaxies nFn few10-13 ergs cm-2 s-1at 1 TeV Implies >> years required to detect n with a km-scale n telescope UHECRs and secondary g rays from clusters? (talk by S. Inoue) Integral photon flux ph(>E cm-2 s-1) • (Armengaud, Sigl, & • Miniati 2006) Berrington and Dermer (2005)

  11. Radio Galaxies and Blazars Cygnus A FR2/FSRQ L ~1045 x (f/10-10 ergs cm-2 s-1) ergs s-1 Mrk 421, z = 0.031 FR1/BL Lac 3C 279, z = 0.538 L ~5x1048 x (f/10-9 ergs cm-2 s-1) ergs s-1 FR1/2 dividing line at radio power 1042 ergs s-1 BL Lacs: optical emission line equivalent widths < 5 Å 3C 296

  12. Redshift Distribution of EGRET g-Ray Blazars

  13. Standard Blazar Model • Collimated ejection of relativistic plasma from supermassive black hole • Relativistic motion accounts for lack of gg attenuation; superluminal motion; super-Eddington luminosities • High energy beamed g rays made in Compton or photo-hadronic processes • FSRQs have intense external radiation field from broad line-region gas

  14. Blazar Main Sequence: Supermassive Black Hole Growth and Evolution FSRQ BL Lac Evolution from FSRQ to BL Lac Objects in terms of a reduction of fuel from surrounding gas and dust Böttcher and Dermer (2000) Cavaliere and d’Elia (2000) Sambruna et al. (1996); Fossati et al. (1998) Understanding the blazar main sequence

  15. Observer Black Hole Jet Physics q Variability and Black Hole Mass Energy Source: Accretion vs. Rotation Two Component Synchrotron/ Compton Leptonic Jet Model Location of g-ray Emission Region BLR clouds G Relativistically Collimated Plasma Outlfows Dusty Torus W Accretion Disk SMBH BL Lac vs. FSRQ Hadronic Jet Model G Ambient Radiation Fields

  16. Leptonic Blazar Modeling Temporally evolving SEDs Evolution of electron distribution with time: information about acceleration (e.g., loop diagrams); Correlated behavior expected for leptonic emissions Infer B field, Doppler power, jet power, location z = 0.538 Böttcher et al. 2007 L ~5x1048 x (f/1014 Jy Hz) ergs s-1

  17. Evidence for Anomalous g-Ray Components in Blazars • Infer intrinsic spectrum with EBL absorption • Implied large Doppler factors of TeV blazars • Orphan TeV flares • Linear jets z = 0.186 Aharonian et al., Nature, 2005

  18. Pictor A d ~ 200 Mpc l jet ~ 1 Mpc (lproj = 240 kpc) Deposition of energy through ultra-high energy neutral beams (Atoyan and Dermer 2003) Pictor A in X-rays and radio(Wilson et al, 2001 ApJ 547)

  19. Blazars as High Energy Hadron Accelerators Powerful blazars / FR-II Neutrons with En > 100 PeV and rays with E > 1PeV take away ~ 5-10 %of the total WCR(E > 1015eV=1 PeV) injected at R<RBLR (3C 279) Synchrotron and IC fluxes from the pair-photon cascade for the Feb 1996 flare of 3C279 dotted -CRs injected during the flare; solid - neutrons escaping from the blob, dashed -neutrons escaping from Broad Line Region (ext. UV) dot-dashed -g rays escaping external UV field (produced by neutrons outside the blob) 3dot-dashed- Protons remaining in the blob atl = RBLR astro-ph/0610195 Sreekumar et al. (1998)

  20. UHE neutrons &  -rays: energy & momentum transport from AGN core • UHE -ray pathlengths in CMBR: l~ 10 kpc - 1Mpc for the En ~ 1016 - 1019 eV • Neutron decay pathlength: ld(n) = 0 c n , (0 ~ 900 s)  ld ~ 1 kpc - 1Mpc for the predicted E~ 1017 - 1020 eV • High redshift jets: photomeson processes on neutrons turn on solid: z = 0 dashed: z = 0.5 Detection of single high-energy n from blazars  neutral beams could power large-scale jets

  21. Neutrinos: expected fluences/numbers Expected  - fluences calculated for 2 flares, in 3C 279 and Mkn 501, assuming proton aceleration rateQprot(acc) = Lrad(obs) ;red curves- contribution due to internal photons, green curves - external component (Atoyan & Dermer 2003) Expected numbers of for IceCube-scale detectors, per flare: • 3C 279: N = 0.35 for  = 6 (solid curve) and N = 0.18 for  = 6 (dashed) Mkn501: N = 1.210-5 for  = 10 (solid) and N = 10-5for  = 25 (dashed) (`persistent')  -level of 3C279 ~ 0.1 F (flare) , ( + external UV for p ) N ~ few - several per year can be expected from poweful HE  FSRQ blazars. N.B. : all neutrinos are expected at E>> 10 TeV

  22. GRBs Long Duration GRBs Massive Star Origin Collapse to Newly Formed Black Hole Prompt phase: internal or external relativistic shocks Afterglow phase: external shock Mean redshift: ~1 (BATSE), ~2 (Swift)GRB/Supernova connection Multiple Classes 1. Long duration GRBs 2. X-ray flashes 3. Low-luminosity GRBs 4. Short Hard Class of GRBs Kouveliotou et al. 1993

  23. Anomalous g-ray Emission Components in GRBs Long (>90 min) g-ray emission (Hurley et al. 1994)

  24. Anomalous High-Energy Emission Components in GRBs Evidence for Second Component from BATSE/TASC Analysis −18 s – 14 s 1 MeV 100 MeV 14 s – 47 s 47 s – 80 s Hard (-1 photon spectral index) spectrum during delayed phase 80 s – 113 s 113 s – 211 s GRB 941017 (González et al. 2003)

  25. Second Gamma-ray Component in GRBs: Other Evidence Sommer et al. 1994 Atkins et al. 2002 Delayed g-ray emission from superbowl burst GRB 930131 Low significance Milagrito detection of GRB 970417A (Requires low-redshift GRB to avoid attenuation by diffuse IR background)

  26. Photon and Neutrino Fluence during Prompt Phase Hard g-ray emission component fromhadronic-induced electromagnetic cascade radiationinside GRB blast wave Second component from outflowing high-energy neutral beam of neutrons, g-rays, and neutrinos Nonthermal Baryon Loading Factor fb = 1 Ftot = 310-4 ergs cm-2 d = 100

  27. Gamma-Ray Bursts as Sources of High-Energy Cosmic Rays Solution to Problem of the Origin of Ultra-High Energy Cosmic Rays (Waxman 1995, Vietri 1995, Dermer 2002) Hypothesis requires that GRBs can accelerate cosmic rays to energies > 1020 eV Injection rate density determined by GRB formation rate (= SFR?) GZK cutoff from photopion processes with CMBR Ankle formed by pair production effects (Wick, Dermer, and Atoyan 2004) (Berezinsky and Grigoreva 1988, Berezinsky, Gazizov, and Grigoreva 2005)

  28. USFR HB06 LSFR Star Formation Rate: Astronomy Input Hopkins & Beacom 2006 Fitting Redshift and Opening-Angle Distribution SFR6, pre-Swift SFR6, Swift SFR6, pre-Swift Le & Dermer 2006

  29. Cosmogenic GZK g-Ray Intensity (Le & Dermer 2006) astro-ph/0611191 Dermer, unpublished calculations, 2007

  30. Neutrinos from GRBs in the Collapsar Model requires Large Baryon-Loading Nonthermal Baryon Loading Factor fb = 20 (~2/yr) (diffuse n background from GRBs: talk by K. Murase) Dermer & Atoyan 2003

  31. Unresolved g-Ray Background BL Lacs: ~2 - 4% (at 1 GeV) FSRQs: ~ 10 - 15% Star-forming galaxies (Pavlidou & Fields 2002)Starburst galaxies(Thompson et al. 2006) Pulsar contribution near 1 GeV Galaxy cluster shocks (Keshet et al. 2003, Blasi Gabici & Brunetti 2007) Dark matter contribution (talk by Bergstrom) astro-ph/0610195 Data: Sreekumar et al. (1998) Strong, Moskalenko, & Reimer (2000)

  32. Summary • GeV g-ray Astronomy: Some Important Problems • Particle acceleration theory • Origin of galactic cosmic rays • Jet physics, differences between radio/g-ray black hole sources • Blazar demographics • Search for hadronic emission components: Acceleration of UHECRs in extragalactic sources (predictions for n astronomy) • Origin of diffuse/unresolved g-ray background Waiting for GLAST…

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