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Neutrino Astronomy. Why Neutrinos Questions in ultra high energy astrophysics Source of UHE cosmic rays GRBs AGN Other Physics Questions – DM, Top Down models, etc Understanding the W-B bound Why the kilometer scale or bigger Overview of experimental approach
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Neutrino Astronomy • Why Neutrinos • Questions in ultra high energy astrophysics • Source of UHE cosmic rays • GRBs • AGN • Other Physics Questions – DM, Top Down models, etc • Understanding the W-B bound • Why the kilometer scale or bigger • Overview of experimental approach • Cherenkov Detectors- IceCube – Nestor, Antares, Baikal • Radio - Rice, Anita, Salsa J. Goodman – Univ. of Maryland
Why Neutrinos J. Goodman – Univ. of Maryland
Why not protons? • Protons are bent in the magnetic fields of our galaxy and local cluster • Energy of >1019eV needed to point back to even galactic sources • Above a few 1019eV GZK cutoff limits their range too J. Goodman – Univ. of Maryland
z = 0.0 z = 0.03 z = 0.1 z = 0.2 z = 0.3 Effect of IR Absorption on Distant Sources IR Model of Stecker & deJager (1998) e- ~TeV g e+ • No direct measurement of IR extragalactic background light exists due to zodiacal foreground. • TeV absorption constrains IR which depends on cosmology of galaxy and star formation models. ~eV g J. Goodman – Univ. of Maryland
Photon Attenuation on IR J. Goodman – Univ. of Maryland
Questions in ultra high energy astrophysics Source of UHE cosmic rays GRBs AGN Dark Matter Other Physics Questions J. Goodman – Univ. of Maryland
Origin of Cosmic Rays Extragalactic flux sets scale for many acceleration models Atmospheric neutrinos See Monday PM & Thursday AM J. Goodman – Univ. of Maryland
Knee Ankle New component with hard spectrum? J. Goodman – Univ. of Maryland
Bottom up GRB fireballs Jets in active galaxies Accretion shocks in galaxy clusters Galaxy mergers Young supernova remnants Pulsars, Magnetars Mini-quasars … Observed showers either protons (or nuclei) Top-down Radiation from topological defects Decays of massive relic particles in Galactic halo Resonant neutrino interactions on relic n’s (Z-bursts) Mostly pions (ns,gs,not protons) Disfavored! Highest energy cosmic rays are not gamma rays Overproduce TeV-neutrinos Alternative Models J. Goodman – Univ. of Maryland
SNRs J. Goodman – Univ. of Maryland
HESS: RXJ1713 First resolved TeV g-ray image of a Shell type SNR (Resolution ~10 arcmin) Acceleration source of Cosmic Rays, but is it evidence of Protons? J. Goodman – Univ. of Maryland
HESS: RXJ1713 – Molecular Clouds J. Goodman – Univ. of Maryland
H.E.S.S.: full remnant CANGAROO: hotspot Index 2.2±0.07±0.1 Index 2.84±0.15±0.20 preliminary RXJ1713 Spectrum See HESS Talk Tuesday Afternoon • In favor of p0: • no cut-off in the • HE tail of HESS • spectrum • signal from the • direction of • molecular clouds J. Goodman – Univ. of Maryland
Have g-rays from p0 decay been discovered? En Nn (En) = EgNg (Eg) 1 < < 8 accelerator beam dump (hidden source) transparent source p0 = p+ = p- n flux predictedobserved g-ray flux ~40 per km2 RX J1713-3946 per year (galactic center) J. Goodman – Univ. of Maryland
Milagro (TeV) Diffuse Source See Milagro Talk Tues Afternoon J. Goodman – Univ. of Maryland
Active Galactic Nuclei Radiation field: Produces cosmic ray beam J. Goodman – Univ. of Maryland
Shock fronts Jets Fermiacceleration Black Hole Accretion Disk Active Galactic Nuclei (AGN) J. Goodman – Univ. of Maryland
VLA image of Cygnus A See Monday Morning AGN Session J. Goodman – Univ. of Maryland
0.6 x 10-27 cm2 π + + μ + e GZK • p + gCMB→p+ + n • = (ncmbsp + g )-1 l= 10 Mpc Cutoff above 50 EeV n n n g p p n E = 6 x10 19 eV E ~4 x 10 19 eV J. Goodman – Univ. of Maryland
GZK Cosmogenic neutrinos are guaranteed if primaries are nucleons. May be much larger fluxes, for some models, such as topological defects J. Goodman – Univ. of Maryland
GZK See Monday PM + Thurs AM Sess. J. Goodman – Univ. of Maryland
GRBs J. Goodman – Univ. of Maryland
GRBs Shocks: external collisions with interstellar material or internal collisions when slower material is overtaken by faster in the fireball. See Wed AM+ Thu PM GRB sessions J. Goodman – Univ. of Maryland
Electron --- Magnetic Field -ray Fireball Phenomenology & The Gamma-Ray Burst (GRB) Neutrino Connection Progenitor (Massive star) 6 Hours 3 Days -ray e- p+ Optical X-ray (2-10 keV) Radio Shock variability is reflected in the complexity of the GRB time profile. E 1051 – 1054 ergs R < 108 cm R 1014 cm, T 3 x 103 seconds Meszaros, P R 1018 cm, T 3 x 1016 seconds J. Goodman – Univ. of Maryland
Lorentz Invariance Violation Bounds on energy dependence of the speed of light can be used to place constraints on the effective energy scale for quantum gravitational effects. E2 = m2c4 +p2c2 -in the Lorentz invariant case, E2-c2p2~E2x(E/EQG)a - This may be modified in some quantum gravity models. This has the important observational consequence that this will give rise to energy dependent delays between arrival times of photons. Dt ~ x(E/EQG)a L/c The expected time delay is : This may be measurable for very high energy photons/neutrinos coming from large distances. See Wed. Afternoon J. Goodman – Univ. of Maryland
Galactic Microquasars See Talk Monday Morning J. Goodman – Univ. of Maryland
What About Dark Matter? • ~85% of the matter in the Universe is Dark Matter • At most a few % of the matter is baryons • Most people believe that the lightest SUSY particle is a stable neutralino and is probably the dark matter • These are weakly interacting and heavy • Evidence of clustering See Friday Afternoon Session on Dark Matter J. Goodman – Univ. of Maryland
c Earth nm Detector Wimp Capture J. Goodman – Univ. of Maryland
Wimp Detection J. Goodman – Univ. of Maryland
Neutrino Astronomy Explores Extra Dimensions 100 x SM GZK range See Wednesday Afternoon Session TeV-scale gravity increases PeV n-cross section J. Goodman – Univ. of Maryland
Cosmic Neutrino Factory black hole radiation enveloping black hole p + g -> n + p+ ~ cosmic ray + neutrino -> p + p0 ~ cosmic ray + gamma J. Goodman – Univ. of Maryland
W-B Bound J. Goodman – Univ. of Maryland
Evading the Bound • “Neutrino only” sources that are optically thick to proton photo-meson interactions and from which protons cannot escape. • No observational evidence (from baryons or high energy photons) • Cores of AGNs (rather than in the jets) by photo-meson interactions or via p−p collisions in a collapsing galactic nucleus or in a cacooned black hole. • The most optimistic predictions of the AGN core model have already been ruled out by AMANDA J. Goodman – Univ. of Maryland
Mannheim, Protheore and Rachen Model J. Goodman – Univ. of Maryland
Neutrinos from Cosmic Rays ~50 events/km2/yr J. Goodman – Univ. of Maryland
Size Perspective for KM3 AMANDAII 300 m 1500 m 50 m 2500 m J. Goodman – Univ. of Maryland
Detection Technique Cerenkov light cone muon or tau interaction detector See Talks in this Session • The muon radiates blue light in its wake neutrino • Optical sensors capture (and map) the light J. Goodman – Univ. of Maryland
Electromagnetic and hadronic cascades ~ 5 m Detection ofe, , O(km) long muon tracks 17 m direction determination by cherenkov light timing J. Goodman – Univ. of Maryland
Muon Events Eµ= 6 PeV Eµ= 10 TeV Measure energy by counting the number of fired PMT. (This is a very simple but robust method) J. Goodman – Univ. of Maryland
Determining Energy 6 PeV m 10 TeV m 375 TeV Cascade J. Goodman – Univ. of Maryland
t + N --> t- + X t + X (82%) Double Bang Learned, Pakvasa, 1995 Regeneration makes Earth quasi transparent for high energie ; (Halzen, Salzberg 1998, …) Also enhanced muon flux due to Secondary µ, and nµ (Beacom et al.., astro/ph 0111482) E << 1PeV: Single cascade (2 cascades coincide) E ≈ 1PeV: Double bang E >> 1 PeV: partially contained (reconstruct incoming tau track and cascade from decay) J. Goodman – Univ. of Maryland
Tau Cascades E << 1PeV: Single cascade (2 cascades coincide) E ≈ 1PeV: Double bang E >> 1 PeV: partially contained (reconstruct incoming tau track and cascade from decay) J. Goodman – Univ. of Maryland
Neutrino ID (solid)Energy and angle (shaded) Neutrino flavor J. Goodman – Univ. of Maryland
Tau Transparency/Regeneration • ne and nµ are absorbed in the Earth via charged current interactions (muons range out) • Above ~100 TeV the Earth is opaque to ne & νµ. • But, the Earth never becomes completely opaque to nt • Due to the short t lifetime, t’s produced in nt charged-current interactions decay back into nt • Also, secondary ne & νµ. fluxes are produced in the tau decays. J. Goodman – Univ. of Maryland
Flavor Ratios • The ratio of flavors at the source is expected to be 0:2:1= nt : nm : ne • Since the distance to the source is >> than the oscillation length – any admixture at the source should wind up: 1:1:1= nt : nm : ne when arriving at earth • What if that isn’t true? J. Goodman – Univ. of Maryland
Exotic neutrino properties if not 1:1:1 • Neutrino decay (Beacom, Bell, Hooper, Pakvasa& Weiler) • CPT violation (Barenboim& Quigg) • Oscillation to steriles with very tiny delta δm2 (Crocker et al; Berezinskyet al.) • Pseudo-Dirac mixing (Beacom, Bell, Hooper, Learned, Pakvasa& Weiler) • 3+1 or 2+2 models with sterile neutrinos (Dutta, Reno and Sarcevic) • Magnetic moment transitions (Enqvist, Keränen, Maalampi) • Varying mass neutrinos (Fardon, Nelson & Weiner; Hung & Pas) J. Goodman – Univ. of Maryland
Count rates 0 5 10 sec Supernova Monitor B10: 60% of Galaxy A-II: 95% of Galaxy IceCube: up to LMC Amanda-II Amanda-B10 IceCube J. Goodman – Univ. of Maryland
Large Scale Neutrino Detectors ANTARES La-Seyne-sur-Mer, France BAIKAL Russia NEMO Catania, Italy See Talks in this Session NESTOR Pylos, Greece IceCube, South Pole, Antarctica J. Goodman – Univ. of Maryland
Radio Cherenkov Detectors Rice Anita Salsa J. Goodman – Univ. of Maryland