Teresa Montaruli, 5 - 7 Apr. 2005 Teresa Montaruli, 5 - 7 Apr. 2005 5 10 : 2 : 1 τ μ e ν ν ν φ : φ : φ i i U 2 , | | | c = cosθ sol , s = sinθ sol , θ sol ~35 o x = sinθ atm = cosθ atm , θ atm ~ 45 0 Δm atm =2.5 10 -3 eV 2 , Δm sol =710 -5 eV 2 For astrophysical sources L>kpc : Δm 2 L/2E » 1 \e e 60% 60% 20% 20% 20% 20% 20% 20% 40% 40% 40% 40% 20% 20% 40% 40% 40% 40% Beam dump when all s decay: 2 1 58 . 0 4 . 0 2 1 58 . 0 4 . 0 0 57 . 0 82 . 0 0 x cx sx x cx sx s c U solar CHOOZ (reactor) atmospheric 2 . 0 2 . 0 6 . 0 e e Neutrino oscillations and Neutrino oscillations and astrophysical fluxes astrophysical fluxes at Earth 0 p e e e j i E L m i j j i i j i e U U U U P , 2 , * , * , , 2 , i i i U U P 2 , 2 , ther scenarios: neutron decay 2 . 0 2 . 0 6 . 0 e e % 20 58 . 0 57 . 0 4 . 0 82 . 0 2 2 2 2 e P
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c = cos θ sol , s = sin θ sol , θ sol ~ 35 o x = sin θ atm = cos θ atm , θ atm ~ 45 0
Neutrino oscillations and astrophysical fluxes. CHOOZ (reactor). solar. atmospheric. at Earth. c = cos θ sol , s = sin θ sol , θ sol ~ 35 o x = sin θ atm = cos θ atm , θ atm ~ 45 0 Δ m atm =2.5 10 -3 eV 2 , Δ m sol =7 10 -5 eV 2. For astrophysical sources L>kpc : - PowerPoint PPT Presentation
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Neutrino production: top downNeutrino production: top downDecay of neutrons in sources Decay or annihilation of supermassive relic of Big Bang 1024 eV = 1015 GeV ~ MGUT (monopoles, topological defects, vibrating strings…)Resonant UHE neutrino interactions on relic neutrinos (Z-bursts)
Guaranteed neutrinos: GZK Guaranteed neutrinos: GZK ssUHECR produce UHECR produce s s s s
s from CR interactions in the s from CR interactions in the Galactic plane Galactic plane
observationsobservations EGRET observed a diffuse emission 100MeV-10 GeV from Galactic Centre EGRET observed a diffuse emission 100MeV-10 GeV from Galactic Centre
region (300 pc): excess > factor 10 around 1 GeV region (300 pc): excess > factor 10 around 1 GeV INTEGRAL: resolved 91 point sources. 90% of ‘diffuse’ flux can be due to INTEGRAL: resolved 91 point sources. 90% of ‘diffuse’ flux can be due to
point sources <100 keVpoint sources <100 keV Milagro: discovery of TeV emission (astr-ph/0502303)Milagro: discovery of TeV emission (astr-ph/0502303) 4.54.5 excess from |b|<5˚ and l excess from |b|<5˚ and l[40˚,100˚][40˚,100˚] Covered pond with 2 layers of PMTs, from relative timing 0.75Covered pond with 2 layers of PMTs, from relative timing 0.75˚ shower direction ˚ shower direction
resolution, gamma-hadron discrimination based on shape of Cherenkov light resolution, gamma-hadron discrimination based on shape of Cherenkov light emitted by showersemitted by showers
observationsobservationsExtreme models Extreme models =-(2.4-2.9) (hard electron disfavoured)s follow primary spectrum ( decay dominates over interactions)New model in Strong, Moskalenko, and Reimer, astro-ph/0406254
Figure: Strong, Moskalenko, and Reimer, astro-ph/0406254
red = from 0
INTEGRAL: flux from point sourcesINTEGRAL: flux from point sources
Galactic CentreGalactic Centre High matter density and activityHigh matter density and activity compact radio source Sgr A* possibly associated to black hole ~3 10compact radio source Sgr A* possibly associated to black hole ~3 106 6 MMsunsun in in
the centerthe center Sgr A East SNRSgr A East SNR
HESS (6.1 4.7h/9.2 11.8 h)
HESS TeV- spectrum in disagreement with the other experiments Variability? localization? HESS 1 arcmin around Sgr A*
Sgr A EastChandra & Radio
Sgr A*
95%68%
astro-ph/0408145
Four 12 m diameter telescopes running since ~ 1yr in Namibia (16 in the future?) Eth 100 GeV
Cherenkov light is emitted by showers induced by high-energy gamma rays This light is very faint - about 10 s/m2 at E=100 GeV - and the duration of the light flash is only a few nsec. Large mirrors, fast photon detectors and short signal-integration times are required to collect enough light from the shower, with minimal contamination from night-sky background light.
direction < 0.1
High Energy Stereoscopic System
Galactic point SourcesGalactic point SourcesThe case of RXJ1713.7-The case of RXJ1713.7-39463946
Open problem: elusive 0 produced in accelerated nuclei collisions with SN ambient material. Still not a clear evidence BUT…CANGAROO claim
ControversialReimer et al., A&A390,2002Incompatible with EGRET
Enomoto et al, Nature 2002
0
RXJ1713.7-3946RXJ1713.7-3946
RXJ1713.7-3946RXJ1713.7-3946Seen by HESSSeen by HESS
H.E.S.S.: full remnantCANGAROO: hotspot
Index 2.2±0.07±0.1
preliminary
Index 2.84±0.15±0.20
NBCANGAROO measures
the spectrum for the NW part of the rim, HESS for
the entire region
No cut-off in the HE tail of HESS spectrum favors 0 decay scenario respect to the case of em processesStudy of electron density and B can help
MicroquasarsMicroquasarsGalactic X-ray binaries with radio relativistic jets Their structure make them similar to quasars but ~106 times smaller Most have bursting activity (hrs-days)Persistent: SS433 GX339-4
Neutrinos from p- interactions (photons from synchr. emissionof electrons accelerated in jet or from accretion disc)
Ljet : jet kinetic power (erg/s) δ : jet Doppler factor δ= γ(1- β cosθ) ηp : fraction of jet energy transferred to protons (~0.1) fπ : fraction of p energy transferred pions D : source distance
Xray afterglow discovery: delayed emission even after ~ 1d optical counterparts SN association: GRB980425-SN1998bw GRB030329-SN2003dh position coincidence and SN like spectrum in afterglowLong GRBs: stellar core collapse into a BH,accretes mass driving a relativistic jet thatpenetrates the mantle and produces GRBControversial: observation off-axis suppresses flux
The fireball modelCompactness problem: the optical depth for pair production very high if initial energy Compactness problem: the optical depth for pair production very high if initial energy emitted from a volume with radius R emitted from a volume with radius R <c dt ~300 km with dt = variability time scale ~ ms <c dt ~300 km with dt = variability time scale ~ ms in in photons photons with the observed spectrum with the observed spectrum this would imply thermal spectra contrary t this would imply thermal spectra contrary t observationsobservations
Solution: relativistic motion Solution: relativistic motion dimension of source R dimension of source R <<22 c dt and E c dt and Eobsobs = = E Emitted mitted
A fireball (A fireball (, e, e, baryon loading <10, baryon loading <10-5 -5 MMsunsun to reach observed to reach observed ) forms due to the high ) forms due to the high energy density, that expands. When it becomes optically thin it emits the observed energy density, that expands. When it becomes optically thin it emits the observed radiation through the dissipation of particle kinetic energy into relativistic shocksradiation through the dissipation of particle kinetic energy into relativistic shocks
External shocks:External shocks: relativistic matter runs on external medium, interstellar or wind earlier relativistic matter runs on external medium, interstellar or wind earlier emitted by the progenitoremitted by the progenitor
Internal shocks:Internal shocks: inner engine emits inner engine emits many shells with different Lorentz many shells with different Lorentz factors colliding into one another, and factors colliding into one another, and thermalizing a fraction of their kinetic thermalizing a fraction of their kinetic energy energy
Rotating massive BH with jets along rotation axis with matter outflow + accretion disc Spectra have a thermal part due to synchrotron radiation of electrons in a magnetic field (UV bump at optical-UV frequencies)+non thermal componentextending up to 20 orders of magnitudeexplained by leptonic/hadronic modelsNeutrino production in p or pp processes
Upper bounds on X-galactic fluxesUpper bounds on X-galactic fluxes
This bound does not apply to harder This bound does not apply to harder spectra or optically thickspectra or optically thick
Cosmic p accelerators produce CRs, ’s and ’s Ultimate bound of any scenario involving and production from s: diffuse extra-galactic background E2F< 6 10-7 GeV /cm2 s sr (EGRET) Measured UHECR flux provides most restrictive limit (Waxman & Bahcall (1999) - optically thin sources: nucleons from photohadronic interactions escape - CR flux above the ankle (>3 ·1018eV) are extragalactic protons with E-2 spectrum E2F< 4.5 10-8 GeV /(cm2 s sr)
Mannheim, Protheroe & Rachen (2000): Magnetic fields and uncertainties in photohadronic interactions of protons can largely affect the bound as these effects restrict number of protons able to escape
Neutrino Detection PrincipleNeutrino Detection Principles are weekly interacting require large target mass andrequire large target mass andconversion into charged particleMarkov/ Greisen idea (1960)Markov/ Greisen idea (1960)
Target is surrounding matterTarget is surrounding matter M =M = RRS (ES (E = 1 TeV : R = 1 TeV : R = 2.5 = 2.5
km)km)
Events are upgoingEvents are upgoing
XN
)(
Muon neutrinosMuon neutrinosare the only topologyare the only topologyto allow source pointingto allow source pointingBut since But since s oscillate s oscillate other topologies shouldother topologies shouldbe considered thatbe considered thatallow to observe upper allow to observe upper skysky
Energy lossesEnergy lossesIonization and atomic excitationIonization and atomic excitation: interactions with electrons in the media: interactions with electrons in the mediaContinuous processContinuous processmip: particles at the minimum of ionization mip: particles at the minimum of ionization 2 MeV/g/cm2 MeV/g/cm22
Radiative: discrete process and stochasticRadiative: discrete process and stochasticBremmsstrahlung:Bremmsstrahlung: radiation emitted by an radiation emitted by anaccelerated or decelerated particle throughaccelerated or decelerated particle throughthe field of an atomic nucleithe field of an atomic nucleiEnergy emitted Energy emitted 1/m1/m22
Pair production:Pair production: +N +N e e++ee--
Photonuclear : Photonuclear : inelastic interaction ofinelastic interaction ofmuons with nuclei, produces hadronic muons with nuclei, produces hadronic showersshowers