The beginning of extra-galactic neutrino astronomy: What have we learned from IceCube’s neutrinos? E. Waxman Weizmann Institute arXiv: arXiv: J. Bahcall, “Neutrino Astronomy” (1989): “The title is more of an expression of hope than a description of the book’s content…”

Cosmic-ray accelerators: What have we learned from IceCube’s neutrinos? E. Waxman Weizmann Institute arXiv: arXiv:

The main driver of HE astronomy: The origin of CRs Cosmic-ray E [GeV] log [dJ/dE] E -2.7 E -3 Heavy Nuclei Protons Light Nuclei? Galactic UHE X-Galactic Source: Supernovae(?) Source? Lighter Where is the G/XG transition?

Consider the rate of CR energy production at UHE, >10 10 GeV; Intermediate E, PeV; “Low” E, ~10 GeV.

UHE: Composition HiRes 2005 Auger 2010 HiRes 2010 (& TA 2011) [Wilk & Wlodarczyk 10]* [*Possible acceptable solution?, Auger collaboration 13]

UHE: Energy production rate & spectrum Protons dQ/d log  =Const.  =0.5(+-0.2) x erg/Mpc 3 yr Mixed composition ct eff [Mpc] log(dQ/d log  ) [erg/Mpc 3 yr] [Katz & EW 09] [Allard 12] GZK

Collisionless shock acceleration The only predictive model. No complete basic principles theory, but - Test particle + elastic scattering assumptions gives v/c<<1: dQ/d log  =Const., v/c~1: dQ/d log  =Const.x  -2/9 (  >>1, isotropic scattering), - Supported by basic principles plasma simulations, - dQ/d log  =Const Observed in a wide range of sources (lower energy p’s in the Galaxy, radiation emission from accelerated e - ). [Krimsky 77] [Keshet & EW 05] [Spitkovsky 06, Sironi & Spitkovsky 09, Keshet et al. 09, …] 200c/  p 40c/  p

Intermediate energy: Neutrinos p +   N +   0  2  ;  +  e + + e +  +   Identify UHECR sources Study BH accretion/acceleration physics For all known sources,   p <=1: If X-G p ’ s:  Identify primaries, determine f(z) [EW & Bahcall 99; Bahcall & EW 01] [Berezinsky & Zatsepin 69]

BBR05 “Hidden” ( only) sources Violating UHECR bound

Bound implications: >1Gton detector 2 flavors, Fermi

   =( )x10 -8 GeV/cm 2 sr s =    WB = 3.4x10 -8 GeV/cm 2 sr s Consistent with Isotropy and with e :  :  =1:1:1 (  deacy + cosmological prop.). IceCube: 37 events at 50Tev-2PeV ~6  above atmo. bgnd. [02Sep14 PRL] A new era in astronomy

IceCube’s detection: Implications Unlikely Galactic: Isotropy, and  2   ~10 -7 (E 0.1TeV ) -0.7 GeV/cm 2 s sr [Fermi]   2  ~10 -9 (E 0.1PeV ) -0.7 GeV/cm 2 s sr <<  WB DM decay? The coincidence of 50TeV<E<2PeV flux, spectrum (& flavor) with the WB bound is unlikely a chance coincidence. XG distribution of sources, (dQ/d log  ) PeV-EeV ~  (dQ/d log  ) >10EeV,   p(pp) >~1 [“Calorimeters”]  Or  (dQ/d log  ) PeV-EeV >>  (dQ/d log  ) >10EeV,   p(pp) <<1  & Coincidence over a wide energy range. (dQ/d log  ) ~  0 implies: p, G-XG transition at ~10 19 eV.

Candidate CR calorimeters: Starburst galaxies Candidate UHECR sources are NOT expected to be “calorimeters” for <100PeV p’s [e.g. Murase et al. 2014]. Radio, IR &  -ray (GeV-TeV) observations  Starbursts are calorimeters for E/Z reaching (at least) 10PeV. Most of the stars in the universe were formed in Starbursts. If CR sources reside in galaxies and Q~Star Formation Rate (SFR), Then  (  <1PeV)~  WB. (And also a significant fraction of the  -bgnd, see Irene’s talk). [Loeb & EW 06]

Low Energy, ~10GeV Our Galaxy- using “grammage” Starbursts- using radio to  observations  Q/SFR similar for different galaxy types, dQ/dlog  ~Const. at all  ! [Katz, EW, Thompson & Loeb 14]

The cosmic ray spectrum [From Helder et al., SSR 12]

The cosmic ray generation spectrum XG CRs XG ’s MW CRs, Starbursts (+ CRs~SFR) [Katz, EW, Thompson & Loeb 14] A single source?

Electromagnetic acceleration in astrophysical sources requires L> L Sun (  2 /  ) (  /Z eV) 2 erg/s GRB: L Sun, M BH ~1M sun, M~1M sun /s,  ~ AGN: L Sun, M BH ~10 9 M sun, M~1M sun /yr,  ~10 1 No steady sources at d<d GZK  Transient Sources (AGN flares?), Charged CRs delayed compared to  ’s. Source candidates & physics challenges Energy extraction; Jet acceleration and content (kinetic/Poynting) Particle acceleration, Radiation mechanisms [Lovelace 76; EW 95, 04; Norman et al. 95]

Identifying the sources IC’s ’s are produced by the “calorimeters” surrounding the sources.  ~1deg  Identification by angular distribution impossible. Our only hope: Identification of transient sources by temporal  association. Requires: Wide field EM monitoring, Real time alerts for follow-up of high E events, and Significant increase of the detector mass at ~100TeV  (source) may be <<  (calorimeter)~  WB [ e.g.  (GRB) ~0.1  WB ] ].

What will we learn from  associations? Identify the CR sources. Resolve key open Qs in the accelerators’ physics (BH jets, particle acceleration, collisionless shocks). Study fundamental/ physics: -  decay  e :  :  = 1:2:0 (Osc.)  e :  :  = 1:1:1    appearance, - GRBs: -  timing (10s over Hubble distance)  LI to 1:10 16 ; WEP to 1:10 6. Optimistically (>100’s of ’ s with flavor identification): Constrain  CP, new phys. [Learned & Pakvasa 95; EW & Bahcall 97] [EW & Bahcall 97; Amelino-Camelia,et al.98; Coleman &.Glashow 99; Jacob & Piran 07] [Blum, Nir & EW 05; Winter 10; Pakvasa 10; … Ng & Beacom 14; Ioka & Murase 14; Ibe & Kaneta 14; Blum, Hook & Murase 14]

Summary IceCube detects extra-Galactic ’s.  =  WB at 50TeV-2PeV. Flux & spectrum of ~10 10 GeV CRs, ~1PeV (and ~10 GeV CRs) Consistent with CR p sources in galaxies, dQ/dlog  ~Const., Q~SFR. * IceCube’s detection consistent with the predicted  (  <1PeV)~  WB from sources residing in starbursts. [A flurry of models post-dicting IceCube’s results by arbitrarily choosing model parameters to match the flux.] * A single type of sources? The sources are unknown. * UHE: L>10 47(50) erg/s, GRBs or bright (to be detected) AGN flares. Temporal  association is key to: CR sources identification, Cosmic accelerators’ physics, Fundamental/ physics.

What is required for the next stage of the astronomy revolution The number of events provided by IceCube E>1 PeV, E>0.1PeV) will not be sufficient for an accurate determination of spectrum, flavor ratio and (an)isotropy.   telescopes M eff (100TeV) expansion to ~10Gton  (IceCube, Km3Net). Wide field EM monitoring. Adequate sensitivity for detecting the ~10 10 GeV GZK ’s.

Backup Slides

UHE, >10 10 GeV, CRs 3,000 km 2 J(>10 11 GeV)~1 / 100 km 2 year 2  sr Ground array Fluorescence detector Auger: 3000 km 2

Where is the G-XG E<10 18 eV ? Fine tuning Inconsistent with Fermi’s XG  (<1TeV) flux  2 (dQ/d  ) =Const E~10 19 eV [Katz & EW 09] [Gelmini 11]

UHE: Do we learn from (an)isotropy? Galaxy density integrated to 75Mpc CR intensity map (  source ~  gal ) [EW, Fisher & Piran 97] Biased (  source ~  gal for  gal >  gal ) [Kashti & EW 08] 98% CL; Consistent with LSS Anisotropy of Z at eV implies Stronger aniso. signal (due to p) at ( /Z) eV Not observed  No high Z at eV [Kotera & Lemoine 08; Abraham et al. 08… Oikonomou et al. 13] [Lemoine & EW 09]

 production: p/A—p/   decay  e :  :  = 1:2:0 (propagation)  e :  :  = 1:1:1 p(A)-p:  /  p ~1/(2x3x4)~0.04 (  p   A /A); - IR photo dissociation of A does not modify  ; - Comparable particle/anti-particle content. p(A)-  :  /  p ~ (0.1—0.5)x(1/4)~0.05; - Requires intense radiation at   >A keV; - Comparable particle/anti-particle content,  e excess if dominated by  resonance (dlog n  /dlog   <-1). [Spector, EW & Loeb 14]

IceCube’s GRB limits [Hummer, Baerwald, and Winter 12; see also Li 12; He et al 12] No ’ s associated with ~200 GRBs (~2 expected). IC analyses overestimate GRB flux predictions, and ignore model uncertainties. IC is achieving relevant sensitivity. [EW & Bahcall 97]

Are SNRs the low E CR sources? So far, no clear evidence. Electromagnetic observations- ambiguous. E.g.: “  decay signature” [Ackermann et al. 13] :