e. waxman weizmann institute
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DESCRIPTIONThe beginning of extra-galactic neutrino astronomy : What have we learned from IceCube’s neutrinos?. arXiv:1312.0558 arXiv:1311.0287. E. Waxman Weizmann Institute. J. Bahcall , “Neutrino Astronomy” (1989 ): “The title is more of an - PowerPoint PPT Presentation
Astrophysical sources of High Energy Neutrinos
The beginning of extra-galactic neutrino astronomy:
What have we learned from IceCubes neutrinos?
E. WaxmanWeizmann InstitutearXiv:1312.0558arXiv:1311.0287J. Bahcall, Neutrino Astronomy (1989): The title is more of anexpression of hope than a description of the books content 1The origin of cosmic-rays at different energies, from a few GeV to 100 EeV, is still unknown. Recent neutrino and cosmic-ray measurements provide new clues to the solution of this old puzzle. I will discuss these new clues, with emphasis on the implications of IceCubes detection of astrophysical high energy neutrinos, the main open questions, and the prospects for progress with future high energy neutrino measurements. The most important step forward would be an identification of the neutrino sources. Such will allow one to identify the UHECR accelerators, to resolve open questions related to the accelerator models, and to study neutrino properties (related e.g. to flavor oscillations and coupling to gravity) with an accuracy many orders of magnitude better than is currently possible. The most promising method for identifying the sources is by association of a neutrino with an electromagnetic signal accompanying a transient event responsible for its generation. The neutrino flux that is produced within the sources, and that may thus be directly associated with transient events, may be significantly lower than the total observed neutrino flux, which may be dominated by neutrino production at the environment in which the sources reside.
Collisionless shock accelerationThe only predictive model.
No complete basic principles theory, but - Test particle + elastic scattering assumptions gives v/c1, isotropic scattering),
- Supported by basic principles plasma simulations,
- dQ/d log e=Const Observed in a wide range of sources (lower energy ps in the Galaxy, radiation emission from accelerated e-).[Krimsky 77][Keshet & EW 05][Spitkovsky 06, Sironi & Spitkovsky 09, Keshet et al. 09, ]200c/wp40c/wp
Intermediate energy: Neutrinosp + g N + p p0 2g ; p+ e+ + ne + nm + nm Identify UHECR sources Study BH accretion/acceleration physicsFor all known sources, tgp1010 GeV;Intermediate E, 1-100 PeV;Low E, ~10 GeV.
UHE: CompositionHiRes 2005
Auger 2010HiRes 2010 (& TA 2011)[Wilk & Wlodarczyk 10]*[*Possible acceptable solution?, Auger collaboration 13]
UHE: Energy production rate & spectrum Protons
dQ/d log e =Const. =0.5(+-0.2) x 1044 erg/Mpc3 yrMixed compositioncteff [Mpc]log(dQ/d log e) [erg/Mpc3 yr]
[Katz & EW 09][Allard 12]GZK
BBR05Hidden (n only) sourcesViolating UHECR bound
Bound implications: >1Gton detector
e2Fn =(2.85+-0.9)x10-8GeV/cm2sr s =e2FWB= 3.4x10-8GeV/cm2sr s Consistent with Isotropy and with ne:nm:nt=1:1:1 (p deacy + cosmological prop.).
IceCube: 37 events at 50Tev-2PeV ~6s above atmo. bgnd. [02Sep14 PRL]A new era in n astronomyIceCubes detection: ImplicationsUnlikely Galactic: Isotropy, and e2Fg~10-7(E0.1TeV)-0.7GeV/cm2s sr [Fermi] e2Fn ~10-9(E0.1PeV)-0.7GeV/cm2s sr > (dQ/d log e) >10EeV, tgp(pp)1011GeV)~1 / 100 km2 year 2p srGround array Fluorescence detector
Auger:3000 km2Where is the G-XG transition? @ EA keV; - Comparable particle/anti-particle content, ne excess if dominated by D resonance (dlog ng/dlog eg