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.
Download ReportTranscript 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.
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 Montréal Jeremy Holmes Florida Institute of Technology Truong Le NRL Nonthermal Neutrinos from Photohadronic Production p g Mücke et al. 1999 p 0 p 2g n n e 3 SOPHIA code Threshold e’ m 140 MeV Neutron b-decay Decay lifetime 900 gn seconds p g p 2g Flavor Changing p 2e 4 g - connection Two-Step Function Approximation Atoyan and Dermer 2003 ( Er ) 340b, 200 MeV Er 500 MeV 120b, Er 500 MeV But without g (buried sources) Kin ( Er ) ˆ 70b, Er 200 MeV g without (leptonic emissions) (useful for energy-loss rate estimates) Nonthermal Neutrinos from Secondary Nuclear Production p N N p 0 p 2g n n e 3 Threshold Ep m 140 MeV 1. Isobaric production near threshold 2. Scaling representation at high energies e.g., Kelner, Aharonian, and Bugayov (PRD, 2006) 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) Dermer 1986 Rules out nuclear production in jet sources (Atoyan & Dermer 2003) Implications of the g/ Connection “Best bet” Sources detection probability Gaisser, Halzen, Stanev 1995 P (e ) 104 e14 , 0.1 e14 (e / 100TeV ) 10 km-scale telescope (IceCube) has best detection probability near 100 TeV Number of detected: N 100 TeV N 2 ( ergs cm ) 10 2 P (e14 ) 10 cm 160ergs / e14 10 4 N ergs cm 2 g 10 4 ergs cm 2 Dermer & Atoyan NJP 2006 Diffuse g Rays and Point Sources of g Rays as Candidate Sources Diffuse Sources of g Rays 1. 2. 3. 4. Diffuse Galactic Gamma Ray Background (Berezinsky et al. 1993) Supernova Remnants Clusters of Galaxies Diffuse Extragalactic Gamma Ray Background Point Sources of g Rays 1. EGRET point source catalog (~ 100 MeV – 5 GeV) (all sky) 2. 3. 4. 5. HESS point source catalog (> 300 GeV – several TeV) MILAGRO/all-sky water Cherenkov VERITAS/MAGIC in Northern Hemisphere GLAST: fall 2007 EGRET Detection Characteristics Spark Chamber (vs. Silicon Tracker in GLAST) Two-week detection threshold 1510-8 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 Catalog of Established High Energy (> 100 MeV) Gamma-Ray Sources GRBs Microquasars 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: ~ 210-4 ergs cm-2 But very soft spectrum s>3–4 Kanbach et al. 1993 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) F = 2.3 10-11 (E/100 MeV)-0.2 ergs cm-2 s-1 >> 2 yrs to detect neutrinos from the LMC Pulsars Brightest persistent g-ray sources Crab nebula F 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 F >> 10-4 ergs cm-2 s-1 But…spectra drop off steeply above 1 – 10 GeV (pulsar), 100 MeV (nebula) Vela pulsar Thompson 2001 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 Microquasars: VHE g-Ray Detection of LS 5039 Confirms ID of Paredes et al. (2000) • HESS Detection of LS 5039 at 200 GeV – 10 TeV Aharonian et al. (2005) • Consistent with point source (< 50) Mean orbital separation d 2.51012 cm (0.2 AU) Companion Mass 23 Mo (Casares et al. 2005) Cui et al. (2005) Multiwavelength Spectrum of LS 5039 RXTE XMM 1 TeV Aharonian et al. (2005) F flux = 10-12 ergs cm-2 s-1 assumed to extrapolate to 100 TeV with s = 2 spectrum requires >>108 sec 3 years to reach fluence level of g >> 10-4 ergs cm-2 s-1 (assuming hadronic emission; cf. Dermer and Böttcher 2006) Generic problem for detecting sources with F flux << 10-11 ergs cm-2 s-1 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 Integral photon flux ph(>E cm-2 s-1) Clusters of Galaxies F few10-13 ergs cm-2 s-1 at 1 TeV Implies >> years required to detect with a km-scale telescope Berrington and Dermer (2005) 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 Photo-hadronic jet models Possible photon targets for p + g : • Internal: synchrotron radiation (Mannheim & Biermann 1992, Mannheim 1993, etc.) requires a compact jet: nphot(e) Lsyn / e 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 =7 (solid) =10 (dashed) =15 (dot-dashed) (red - without ADR) (Atoyan & Dermer 2001) quasi-isotropic, up to RBLR~ 0.1-1 pc Impact of the external ADR component: available on yrs scale (independent of L) high pg-rates & lower threshold energies: prot MeV/(1- cos) e (for 1996 flare of 3C 279) Neutron & g -ray energy spectra & beam power Powerful FSRQ blazars / FR-II Radio Galaxies ● Neutrons with En > 100 PeV and grays with Eg > 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, and dashed- neutrons escaping from BL region (ext. UV) dot-dashed- grays escaping external UV filed (produced by neutrons outside the blob) dotted- CRs injected during the flare, and 3dot-dashed- remaining in the blob at l = RBLR ● Total energetics in UHE particles ( for parameters of the Feb 96 flare) =10 : WCR(>1 PeV) = 6 1051 erg, Wn / WCR = 3.3%, Wg /WCR = 4.4% =15 : WCR(>1 PeV) = 3.1 1051 erg, Wn / WCR = 8.9 %, Wg /WCR = 0.9% ● Particle energies in the neutral beam Eg ~ 1PeV- 3 EeV , En ~ 10PeV - 30 EeV Neutron & g - ray beams in BL Lacs/FR-I neutrons with En > 100 PeV and grays with Eg > 1PeV take away << 0.1 % of the total injected WCR(E > 1 PeV) 'Mkn 501' Blue solid- neutrons escaping from the blob and external field, 3dot-dashed- neutrinos dot-dashed- grays escaping external filed dotted- protons injected during the flare, and thin solid - protons remaining at l = RBLR ● UHE neutral beam energetics (stationary frame): =10 : WCR(>1 PeV) = 5.2 1048 erg, Wn / WCR = 3.3 10- 4 , Wg /WCR = 4.3 10 - 7 =25 : WCR(>1 PeV) = 5.3 1047 erg, Wn / WCR = 4.5 10- 4, Wg /WCR = 1.6 10- 4 ● Particle energies in the neutral beam Eg < 1 EeV , En ~ 30PeV - 5 EeV Neutrinos: expected fluences/numbers Expected - fluences calculated for 2 flares, in 3C 279 and Mkn 501, assuming proton aceleration rate Qprot(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 = 1.2 10-5 for = 10 (solid) and N = 10-5 for = 25 (dashed) (`persistent') g -level of 3C279 ~ 0.1 Fg (flare) , ( + external UV for pg ) N ~ few- several per year can be expected from poweful HE g FSRQ blazars. N.B. : all neutrinos are expected at E>> 10 TeV UHE neutrons & g -rays: energy & momentum transport from AGN core UHE g-ray pathlengths in CMBR: lgg ~ 10 kpc - 1Mpc solid: z=0 dashed: z = 0.5 for the predicted E~ 1016 - 1019 eV • neutron decay pathlength: ld (gn) = 0 c gn , ( 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 ? (!) ( ??? ) 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) Fluence Distribution of GRBs Fluence distribution of 2135 BATSE GRBs N ( e ) e de1 e12 P A 0.6f 4 A10 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 f McCullough (2001) Photon and Neutrino Fluence during Prompt Phase Nonthermal Baryon Loading Factor fb = 1 tot = 310-4 ergs cm-2 = 100 Hard g-ray emission component from hadronic-induced electromagnetic cascade radiation inside GRB blast wave Second component from outflowing high-energy neutral beam of neutrons, g-rays, and neutrinos pg e ( n, p, ) 0 2g e Evidence for Anomalous g-ray Emission Components in GRBs Long (>90 min) g-ray emission (Hurley et al. 1994) GRB 940217 Nonthermal processes Two components seen in two epochs MeV synchrotron and GeV/TeV SSC gg lower limit to the Two components seen in two separate epochs bulk Lorentz factor How to explain the two components? of the outflow How to explain the two components? Anomalous High-Energy Emission Components in GRBs Evidence for Second Component from BATSE/TASC Analysis −18 s – 14 s 1 MeV 14 s – 47 s 47 s – 80 s 80 s – 113 s Hard (-1 photon spectral index) spectrum during delayed phase 113 s – 211 s GRB 941017 (González et al. 2003) 100 MeV 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) Swift Observations of Rapid X-Ray Temporal Decays Tagliaferri et al. (2005) O’Brien et al. (2006) Rates for 1020 eV Protons with Equipartition Parameters Standard blast wave model with external density = 1000 cm-3, z = 1 Rapid blast wave deceleration from radiative discharge causes rapid X-ray declines 10 -2 r Calculated at E =10 20 p esc eV -1 Comovin Rates (s ) Within the available time, photopion losses and escape cause a discharge of the proton energy several hundred seconds after GRB 10 -3 r r 10 -4 10 -5 1/t' acc ava p,syn 1 r 10 100 Observer time t(s) Dermer 2006 1000 f Neutrinos from GRBs in the Collapsar Model requires Large Baryon-Loading Nonthermal Baryon Loading Factor fb = 20 (~2/yr) Dermer & Atoyan 2003 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 (Berezinsky and Grigoreva 1988, Berezinsky, Gazizov, and Grigoreva 2005) (Wick, Dermer, and Atoyan 2004) Star Formation Rate: Astronomy Input USFR LSFR HB06 Hopkins & Beacom 2006 Fitting Redshift and Opening-Angle Distribution SFR6, pre-Swift SFR6, Swift Le & Dermer 2006 SFR6, pre-Swift UHECR Spectra for Different SFRs Provides good fits to HiRes data with fCR 50 - 70 Waiting for next data release of Auger fCR 50 GZK neutrinos from UHECRs produced by GRBs Assume GRBs inject power-law distribution with exponentional cutoff energy = 1020 eV with rate density different SFR histories f = 50 CR RICE Halzen & Hooper 2006 AMANDA Dermer & Holmes 2006 Summary g - Connection g-ray fluence (extrapolated to 100 TeV) > 10-4 ergs cm-2 required for detection for optically thin sources Best bet for detectable neutrino point source with km-scale 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 Lots of room for surprises…