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Armen Atoyan U. de Montr é al Jeremy Holmes Florida Institute of Technology Truong Le NRL

Astrophysical Sources of Neutrinos and Expected Rates Chuck Dermer U.S. Naval Research Laboratory TeV Particle Astrophysics II Madison, Wisconsin August 28, 2006. Armen Atoyan U. de Montr é al Jeremy Holmes Florida Institute of Technology Truong Le NRL.

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Armen Atoyan U. de Montr é al Jeremy Holmes Florida Institute of Technology Truong Le NRL

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  1. Astrophysical Sources of Neutrinos and Expected RatesChuck DermerU.S. Naval Research LaboratoryTeV Particle Astrophysics II Madison, WisconsinAugust 28, 2006 Armen AtoyanU. de MontréalJeremy HolmesFlorida Institute of TechnologyTruong LeNRL

  2. Nonthermal Neutrinos from Photohadronic Production Mücke et al. 1999 SOPHIA code Threshold e’ mp  140 MeV Neutron b-decay Flavor Changing Decay lifetime  900 gn seconds Two-Step Function Approximation Atoyan and Dermer 2003 g - n connection But n without g (buried sources) g without n(leptonic emissions) (useful for energy-loss rate estimates)

  3. Nonthermal Neutrinos from Secondary Nuclear Production Threshold Ep mp  140 MeV 1. Isobaric production near threshold 2. Scaling representation at high energies e.g., Kelner, Aharonian, and Bugayov (PRD, 2006) Dermer 1986 Photon Targets (high radiation energy density and either VHE photons or particles) vs. Particle Targets (high target particle density but relatively low nonthermal particle energies) Rules out nuclear production in jet sources (Atoyan & Dermer 2003)

  4. “Best bet” Sources • nm detection probability Implications of the g/n Connection Gaisser, Halzen, Stanev 1995 km-scale n telescope (IceCube) has best detection probability near 100 TeV Number of nm detected: 100 TeV Dermer & Atoyan NJP 2006

  5. Diffuse g Rays and Point Sources of g Rays as Candidate n Sources • Diffuse Sources of g Rays • Diffuse Galactic Gamma Ray Background (Berezinsky et al. 1993) • Supernova Remnants • Clusters of Galaxies • Diffuse Extragalactic Gamma Ray Background • Point Sources of g Rays • EGRET point source catalog (~ 100 MeV – 5 GeV) (all sky) • HESS point source catalog (> 300 GeV – several TeV) • MILAGRO/all-sky water Cherenkov • VERITAS/MAGIC in Northern Hemisphere • GLAST: fall 2007

  6. EGRET Detection Characteristics • Spark Chamber (vs. Silicon Tracker in GLAST) • Two-week detection threshold • 1510-8 ph(>100 MeV) cm-2 s-1 • (Dermer & Dingus 2004) • (high-latitude sources; background limited) • Hard spectrum (photon index s < 2) • Energy range: ~100 MeV – 5 GeV • Threshold energy flux: 10-10 ergs cm-2 s-1 • Two week observation: ~106 sec • Threshold fluence: 10-4 ergs cm-2 s-1 • Therefore examine which EGRET sources are bright and have hard spectra

  7. Catalog of Established High Energy (> 100 MeV) Gamma-Ray Sources GRBs Microquasars

  8. Solar g-Ray Flares June 11, 1991 Flare Spectrum g-ray spectrum fit by slow-decaying (~255 minutes) pion emission and fast-decaying (~25 minutes) electron bremsstrahlung Energy flux at 100 MeV: ~ 10-8 ergs cm-2 s-1 Energy fluence at 100 MeV: ~ 210-4 ergs cm-2 But very soft spectrum s > 3 – 4 Kanbach et al. 1993

  9. Large Magellanic Cloud • Measured Integral Flux: • fg= 19  10-8 ph(>100 MeV) cm-2 s-1 • (Sreekumar et al. 1992) • “resulting spectral shape consistent with that expected from cosmic ray interactions with matter” • Third EGRET catalog • (Hartman et al. 1999) • fg = 14.4(±4.7)  10-8 ph(>100 MeV) cm-2 s-1 • s = 2.2(±0.2)  nFn = 2.3  10-11 (E/100 MeV)-0.2 ergs cm-2 s-1  >> 2 yrs to detect neutrinos from the LMC

  10. Pulsars Brightest persistent g-ray sources nFn10-3 MeV cm-2 s-1 10-6 GeV cm-2 s-1 10-9 ergs cm-2 s-1 Therefore require only >> 105 s ~ 1 day to reach nFn>>10-4 ergs cm-2 s-1 But…spectra drop off steeply above 1 – 10 GeV (pulsar), 100 MeV (nebula) Crab nebula Vela pulsar de Jager et al. 1999 • Pulsed component consistent with electromagnetic cascade radiation in polar cap or outer gap • Nebular component consistent with synchrotron + SSC component from cold MHD wind Thompson 2001

  11. Confirms ID of Paredes et al. (2000) • HESS Detection of LS 5039 at  200 GeV – 10 TeV • Consistent with point source (< 50) Microquasars: VHE g-Ray Detection of LS 5039 Aharonian et al. (2005) Mean orbital separation d 2.51012 cm (0.2 AU) Companion Mass  23 Mo(Casares et al. 2005) Cui et al. (2005)

  12. Multiwavelength Spectrum of LS 5039 RXTE XMM nFn flux = 10-12 ergs cm-2 s-1assumed to extrapolate to 100 TeV with s = 2 spectrum requires >>108 sec  3 years to reach fluence level of Fg>>10-4 ergs cm-2 s-1 (assuming hadronic emission; cf. Dermer and Böttcher 2006) Generic problem for detecting sources with nFn flux << 10-11 ergs cm-2 s-1 1 TeV Aharonian et al. (2005)

  13. EGRET Unidentified Sources Geminga-like pulsars Pulsar wind nebulae Dark dust complexes irradiated by cosmic rays Grenier et al. (2005) Low-mass microquasars Background AGNs Clusters of Galaxies

  14. 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 Integral photon flux ph(>E cm-2 s-1) Berrington and Dermer (2005)

  15. 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 3C 296 L ~5x1048 x (f/10-9 ergs cm-2 s-1) ergs s-1

  16. Photo-hadronic jet models Possible photon targets forp +: • Internal: synchrotron radiation (Mannheim & Biermann 1992, Mannheim 1993, etc.) requires a compact jet: nphot()  Lsyn /Rjet2 target disappears with jet expansion on: t ' ~ R'jet/c ~ tvar/(1+z) • External: accretion disk radiation (UV) (i)direct ADR: (Bednarek & Protheroe 1999) anisotropic, effective up to R < 100 Rgrav < 0.01 pc (ii) ADR scattered in the Broad-Line region (Atoyan & Dermer 2001) quasi-isotropic,up toRBLR~ 0.1-1 pc • Impact of the external ADR component: available on yrs scale (independent of L) high p-rates & lower threshold energies: protMeV/(1- cos) =7 (solid) =10 (dashed) =15 (dot-dashed) (red - without ADR) (for 1996 flare of 3C 279)

  17. Neutron & -rayenergy spectra & beam power Powerful FSRQ blazars / FR-II Radio Galaxies • 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) solid- neutrons escaping from the blob, anddashed-neutrons escaping from BL region (ext. UV) dot-dashed-rays escaping external UV filed (produced by neutrons outside the blob) dotted-CRs injected during the flare, and3dot-dashed-remaining in the blob atl = RBLR • Total energetics in UHE particles ( for parameters of the Feb 96 flare) =10: WCR(>1 PeV) = 6 1051erg, Wn / WCR =3.3%, W /WCR =4.4% =15: WCR(>1 PeV) = 3.1 1051erg, Wn / WCR =8.9 %, W /WCR = 0.9% • Particle energies in the neutral beam E ~ 1PeV- 3 EeV , En ~ 10PeV - 30 EeV

  18. Neutron &- ray beams in BL Lacs/FR-I 'Mkn 501' neutrons with En > 100 PeV and rays with E > 1PeV take away << 0.1 %of the total injected WCR(E > 1 PeV) Blue solid- neutrons escaping from the blob and external field, 3dot-dashed-neutrinos dot-dashed-rays escaping external filed dotted- protons injected during the flare, and thin solid - protons remaining atl = RBLR • UHE neutral beam energetics (stationary frame): =10: WCR(>1 PeV) = 5.2 1048erg, Wn / WCR =3.3 10- 4 , W /WCR =4.3 10 - 7 =25: WCR(>1 PeV) = 5.3 1047erg, Wn / WCR =4.5 10- 4, W /WCR = 1.6 10- 4 • Particle energies in the neutral beam E < 1 EeV , En ~ 30PeV - 5 EeV

  19. 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

  20. UHE neutrons &  -rays: energy & momentum transport from AGN core • UHE -ray pathlengths in CMBR: l~ 10 kpc - 1Mpc for the predicted E~ 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 • a new interpretation for large-scale jets ? (!) ( ??? ) solid: z = 0 dashed: z = 0.5

  21. Pictor A d ~ 200 Mpc l jet ~ 1 Mpc (lproj = 240 kpc) LX(jet) = 1.4 1041 erg/s LX(h.spot) = 1.7 1042 erg/s x ~ 1.1, radio ~ 0.8  S(syn.lobes) ~ 10-11 erg/cm2 s Pictor A in X-rays and radio(Wilson et al, 2001 ApJ 547)

  22. Fluence Distribution of GRBs Fluence distribution of 2135 BATSE GRBs Detection of neutrinos requires GRBs at fluence levels > 3x10-4 ergs/cm2 (2-5 GRBs per year at this level) unless GRBs are hadronically dominated McCullough (2001)

  23. 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

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

  25. GRB 940217 • Nonthermal processes • Two components seen in two epochs • MeV synchrotron and GeV/TeV SSC • g-g lower limit to the bulk Lorentz factor G of the outflow • How to explain the two components? Two components seen in two separate epochs How to explain the two components?

  26. 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)

  27. Second Gamma-ray Component in GRBs: Other Evidence Atkins et al. 2002 Bromm & Schaefer 1999 (Requires low-redshift GRB to avoid attenuation by diffuse IR background) Delayed high-energy g-ray emission from superbowl burst Seven GRBs detected with EGRET either during prompt MeV burst emission or after MeV emission has decayed away (Dingus et al. 1998) Average spectrum of 4 GRBs detected over 200 s time interval from start of BATSE emission with photon index 1.95(0.25) (> 30 MeV)

  28. O’Brien et al. (2006) Swift Observations of Rapid X-Ray Temporal Decays Tagliaferri et al. (2005)

  29. Rates for 1020 eV Protons with Equipartition Parameters Standard blast wave model with external density = 1000 cm-3, z = 1 Within the available time, photopion losses and escape cause a discharge of the proton energy several hundred seconds after GRB Rapid blast wave deceleration from radiative discharge causes rapid X-ray declines Dermer 2006

  30. Neutrinos from GRBs in the Collapsar Model requires Large Baryon-Loading Nonthermal Baryon Loading Factor fb = 20 (~2/yr) Dermer & Atoyan 2003

  31. 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 [air production effects (Wick, Dermer, and Atoyan 2004) (Berezinsky and Grigoreva 1988, Berezinsky, Gazizov, and Grigoreva 2005)

  32. 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

  33. UHECR Spectra for Different SFRs Provides good fits to HiRes data with fCR 50 - 70 Waiting for next data release of Auger fCR 50

  34. Assume GRBs inject power-law distribution with exponentional cutoff energy = 1020 eV with rate density  different SFR histories GZK neutrinos from UHECRs produced by GRBs fCR= 50 Halzen & Hooper 2006 RICE AMANDA Dermer & Holmes 2006

  35. g -nConnectiong-ray fluence (extrapolated to 100 TeV) > 10-4 ergs cm-2 required for n detection for optically thin sources Best bet for detectable neutrino point source with km-scale n detector (IceCube): v from photohadronic processes Blazar AGNs (FSRQs, not BL Lacs) Surrounding target radiation field; 1 PeV neutrino GRBs Signatures of hadronic acceleration in GRBs Microquasars (?) probably too weak Best bet for detectable diffuse neutrino sources: GZK neutrinos from cosmological sources of UHECRs (GRBs) Cosmic-ray induced galactic diffuse emission Summary Lots of room for surprises…

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