Multi-messenger aspects of the IceCube excess

Transcription

1 Multi-messenger aspects of the IceCube excess Markus Ahlers UW-Madison & WIPAC Cosmic Messages in Ghostly Bottles CCAPP, February 27/28, 2014

2 Multi-messenger paradigm Neutrino astronomy: natural extension: optical + multi-wavelength + multi-messenger closely related to cosmic rays (CRs) and γ-rays smoking-gun of CR sources weak interaction during propagation Challenges: CR ν γ low statistics large backgrounds

3 High-energy neutrino detection High energy neutrino collisions with nuclei are rare. Backgrounds are huge and partially irreducible! back-of-the-envelope (E ν 15 ev): flux of neutrinos : d 2 N ν dt da 1 cm 2 5 yr cross section : σ νn 33 cm 2 targets: N N N A V/cm 3 rate of events : Ṅ ν N N σ νn d2 N ν dt da 1 year V 1km 3

4 Multi-messenger paradigm pion production in CR interactions with ambient radiation & matter π + µ + ν µ e + ν e ν µν µ π 0 γγ ν inelasticity: E ν E γ/2 κe p/4 relative multiplicity: K = N π ±/N π 0 CR γ pion fraction via optical depth: f π 1 e κτ

5 Multi-messenger paradigm pion production in CR interactions with ambient radiation & matter inelasticity: π + µ + ν µ e + ν e ν µν µ π 0 γγ E ν E γ/2 κe p/4 relative multiplicity: K = N π ±/N π 0 3 Kf π 4 1+K E2 pj p E 2 νj ν 3K 4 E2 γj γ pion fraction via optical depth: (E 2 νj ν energy density ω) f π 1 e κτ

6 Multi-messenger paradigm pion production in CR interactions with ambient radiation & matter inelasticity: π + µ + ν µ e + ν e ν µν µ π 0 γγ E ν E γ/2 κe p/4 relative multiplicity: 3 Kf π 4 1+K E2 pj p E 2 νj ν 3K 4 E2 γj γ K = N π ±/N π 0 pion fraction via optical depth: f π 1 e κτ ω γ bgr 6 7 ev/cm 3 ω UHECR 1 7 ev/cm 3 ω νall 2 8 ev/cm 3

7 IceCube excess IceCube observes 28 events over a period of two years, while are expected from atmospheric contributions. flux excess at 4.1σ for combined 26+2 fit [ talk by C.Kopper tomorrow; IceCube arxiv: ] isotropic and flavor-universal no significant time-clustering small excess in the Southern Hemisphere even after correction for zenith angle dependent acceptance E 2 spectrum favors cutoff/break at 2 5 PeV best-fit of the HESE spectrum E 2 νj IC ν α (1.2 ± 0.4) 8 GeVs 1 cm 2 sr 1

8 IceCube excess 90 o o 13 1 Galactic Plane Northern Hemisphere Southern Hemisphere o Galactic -180 o [data from IceCube arxiv: (without muon 28)]

9 IceCube excess HI column density [cm 2 ] o 13 1 Galactic Plane Northern Hemisphere Southern Hemisphere o Galactic -180 o 1e+20 1e+22

10 IceCube excess Fermi Bubbles 17 Bubble o 13 1 Galactic Plane Northern Hemisphere Southern Hemisphere o Galactic -180 o

11 IceCube excess Ursa Willman Major 1 I Ursa Minor Ursa Major II Draco Local Group Canes Venatici II Boötes III Boötes III 17 Hercules 23 Coma Berenices 16 8 Leo IV Leo II 9 Segue Sextans 180 o 13 Segue 2 1 Galactic Plane Northern Hemisphere Southern Hemisphere Pisces II Sagittarius o 7 Sculptor Canis Major Carina Large 19 Magellanic Cloud Small 20 Magellanic Cloud Fornax Galactic -180 o

12 IceCube excess Galaxy Groups in Virgo Supercluster Canes I NGC5194 M81 M NGC2403 NGC5128, Cen A 180 o 13 Maffei Galactic Plane NGC672 1 Northern Hemisphere Southern Hemisphere NGC45 Sculptor -90 o Galactic -180 o

13 Multi-messenger paradigm Neutrino production is closely related to the production of cosmic rays (CRs) and γ-rays. 1 PeV neutrinos correspond to 20 PeV CR nucleons and 2 PeV γ-rays ν very interesting energy range: Glashow resonance? galactic or extragalactic? isotropic or point-sources? chemical composition? pp or pγ origin? CR γ

14 Multi-messenger paradigm TeVCat g-ray sources o 13 1 Galactic Plane Northern Hemisphere Southern Hemisphere o Galactic -180 o LBL, IBL, LBL, FRI, FSRQ Globular Cluster, Star Forming Region, Massive Star Cluster Binary PWN Shell, SNR/Molec.Cloud, Composite SNR Starburst Others [TeVCat 14]

15 Multi-messenger paradigm Auger 20 E > 55 EeV o 13 1 Galactic Plane Northern Hemisphere Southern Hemisphere o Galactic -180 o ( ) 1( ) D θ 1 2 E 1 ( ) ( ) λcoh B λ coh 55EeV 1Mpc 1nG [Waxman & Miralda-Escude 96]

16 Anisotropies & Variation Statistical distribution of local sources via anisotropies and ensemble variations. anisotropy 200Mpc ensemble variationen 200Mpc

17 Point Sources or Diffuse Emission? diffuse extragalactic neutrino flux J ν(e ν) = 1 4π 0 dz H(z)Qν((1 + z)eν) H(z) source red-shift evolution H and emission rate density Q ν E γ source red-shift distribution p(z) = Ωd 2 C(z)H(z)/H(z) ensemble variation: [Lee 79;MA,Anchordoqui&Taylor 13] J 2 [ ] σ 2 ν (1 + z) γ 2 [ ] 2 (1 + z) γ 1 = = dzp(z) dzp(z) J ν 2 4πdC 2 4πdC 2 n s( Ω) H = H 0(1 + z) 3 with z min < z < 2, power index γ = 2: ( σ 0.05 H 0 5 Mpc 3 ) 1/2 ( zmin ) 1/2 ( θres local fluctuation very low except for very nearby or rare sources! ) 1

18 Conceivable PeV neutrino fluxes more ν flux properties (non-icecube & preliminary data): Glashow-excitement [Barger, Learned & Pakvasa ; Bhattacharya et al ] spectral features [Laha et al ; Anchordoqui et al ;He et al ] flavor composition [Winter ] neutrinos form pp interactions follow CR spectrum: E ν,max 1 20 Ep,max typical neutrino energy from pγ interactions (in boosted environments): E ν,pk 1 20 Γ2 m 2 m 2 p 4E γ 8PeV Γ 2 ( ) ev GZK neutrinos from optical-uv background (Γ 1 / E γ ev) [Berezinsky&Zatsepin 69; Roulet et al ] prompt neutrino emission in GRBs (Γ 300 / E γ 1 MeV) [Waxman&Bahcall 97] E γ prompt neutrino contribution? [Enberg, Reno & Sarcevic 08; Lipari ]

19 Conceivable PeV neutrino fluxes more ν flux properties (non-icecube & preliminary data): Glashow-excitement [Barger, Learned & Pakvasa ; Bhattacharya et al ] spectral features [Laha et al ; Anchordoqui et al ;He et al ] flavor composition [Winter ] neutrinos form pp interactions follow CR spectrum: E ν,max 1 20 Ep,max typical neutrino energy from pγ interactions (in boosted environments): E ν,pk 1 20 Γ2 m 2 m 2 p 4E γ 8PeV Γ 2 ( ) ev GZK neutrinos from optical-uv background (Γ 1 / E γ ev) [Berezinsky&Zatsepin 69; Roulet et al ] prompt neutrino emission in GRBs (Γ 300 / E γ 1 MeV) [Waxman&Bahcall 97] E γ prompt neutrino contribution? [Enberg, Reno & Sarcevic 08; Lipari ]

20 Conceivable PeV neutrino fluxes more ν flux properties (non-icecube & preliminary data): Glashow-excitement [Barger, Learned & Pakvasa ; Bhattacharya et al ] spectral features [Laha et al ; Anchordoqui et al ;He et al ] flavor composition [Winter ] neutrinos form pp interactions follow CR spectrum: E ν,max 1 20 Ep,max typical neutrino energy from pγ interactions (in boosted environments): E ν,pk 1 20 Γ2 m 2 m 2 p 4E γ 8PeV Γ 2 ( ) ev GZK neutrinos from optical-uv background (Γ 1 / E γ ev) [Berezinsky&Zatsepin 69; Roulet et al ] prompt neutrino emission in GRBs (Γ 300 / E γ 1 MeV) [Waxman&Bahcall 97] E γ prompt neutrino contribution? [Enberg, Reno & Sarcevic 08; Lipari ]

21 Conceivable PeV neutrino fluxes more ν flux properties (non-icecube & preliminary data): Glashow-excitement [Barger, Learned & Pakvasa ; Bhattacharya et al ] spectral features [Laha et al ; Anchordoqui et al ;He et al ] flavor composition [Winter ] neutrinos form pp interactions follow CR spectrum: E ν,max 1 20 Ep,max typical neutrino energy from pγ interactions (in boosted environments): E ν,pk 1 20 Γ2 m 2 m 2 p 4E γ 8PeV Γ 2 ( ) ev GZK neutrinos from optical-uv background (Γ 1 / E γ ev) [Berezinsky&Zatsepin 69; Roulet et al ] prompt neutrino emission in GRBs (Γ 300 / E γ 1 MeV) [Waxman&Bahcall 97] E γ prompt neutrino contribution? [Enberg, Reno & Sarcevic 08; Lipari ]

22 Proposed source candidates extragalactic sources: relation to the sources of UHE CRs [Kistler, Stanev & Yuksel ] GZK from low E max blazars [Kalashev, Kusenko & Essey ] cores of active galactic nuclei (AGN) [Stecker et al. 91;Stecker ] low-power γ-ray bursts (GRB) [Murase & Ioka ] starburst galaxies [Loeb&Waxman 06; He et al ; Murase, MA & Lacki ] hypernovae in star-forming galaxies [Liu, Wang, Inoue, Crocker & Aharonian ] galaxy clusters/groups [Berezinksy, Blasi & Ptuskin 97; Murase, MA & Lacki ] Galactic sources: heavy dark matter decay [Feldstein et al ; Esmaili & Serpico ] peculiar hypernovae [Fox, Kashiyama & Meszaros ; MA & Murase ] diffuse Galactic γ-ray emission [e.g. Ingelman & Thunman 96; MA & Murase ] γ-ray association: unidentified Galactic TeV γ-ray sources [Fox, Kashiyama & Meszaros ] sub-tev diffuse Galactic γ-ray emission [Neronov, Semikoz & Tchernin ]

23 Proposed source candidates extragalactic sources: relation to the sources of UHE CRs [Kistler, Stanev & Yuksel ] GZK from low E max blazars [Kalashev, Kusenko & Essey ] cores of active galactic nuclei (AGN) [Stecker et al. 91;Stecker ] low-power γ-ray bursts (GRB) [Murase & Ioka ] starburst galaxies [Loeb&Waxman 06; He et al ; Murase, MA & Lacki ] hypernovae in star-forming galaxies [Liu, Wang, Inoue, Crocker & Aharonian ] galaxy clusters/groups [Berezinksy, Blasi & Ptuskin 97; Murase, MA & Lacki ] Galactic sources: heavy dark matter decay [Feldstein et al ; Esmaili & Serpico ] peculiar hypernovae [Fox, Kashiyama & Meszaros ; MA & Murase ] diffuse Galactic γ-ray emission [e.g. Ingelman & Thunman 96; MA & Murase ] γ-ray association: unidentified Galactic TeV γ-ray sources [Fox, Kashiyama & Meszaros ] sub-tev diffuse Galactic γ-ray emission [Neronov, Semikoz & Tchernin ]

24 Proposed source candidates extragalactic sources: relation to the sources of UHE CRs [Kistler, Stanev & Yuksel ] GZK from low E max blazars [Kalashev, Kusenko & Essey ] cores of active galactic nuclei (AGN) [Stecker et al. 91;Stecker ] low-power γ-ray bursts (GRB) [Murase & Ioka ] starburst galaxies [Loeb&Waxman 06; He et al ; Murase, MA & Lacki ] hypernovae in star-forming galaxies [Liu, Wang, Inoue, Crocker & Aharonian ] galaxy clusters/groups [Berezinksy, Blasi & Ptuskin 97; Murase, MA & Lacki ] Galactic sources: heavy dark matter decay [Feldstein et al ; Esmaili & Serpico ] peculiar hypernovae [Fox, Kashiyama & Meszaros ; MA & Murase ] diffuse Galactic γ-ray emission [e.g. Ingelman & Thunman 96; MA & Murase ] γ-ray association: unidentified Galactic TeV γ-ray sources [Fox, Kashiyama & Meszaros ] sub-tev diffuse Galactic γ-ray emission [Neronov, Semikoz & Tchernin ]

25 T I i ' ' a) Active Galactic Nuclei neutrino interactions from pγ interactions in AGN cores AGN diffuse emission normalized to X-ray background revised model predicts 5% of original estimate " 2, &) t rnosph eri» 14 IceCube excess [Steckeret al. 91] [Stecker 05; 13] 03 U 0 22 " x i TTTTTTT i 1T1TITTl T TTT~ 1WTT~ i i i iiiq T i ' ' '. : ' ' ('.)' 'l 0' 'l 0' i, ( T T I I lliii I i i I IIII' I i I I i III i Illa' 1(3 'I (;I' [Stecker et al. 91]

26 b) Gamma-ray Bursts strong limits on neutrino emission associated with the fireball model [Abbasi et al. 12] IceCube excess exceeds IC40+59 limit by factor 5 loophole: undetected low-power γ-ray bursts (GRB) [Murase & Ioka ] talk by K.Murase this morning IceCube excess Waxman & Bahcall IC40 limit IC40 Guetta et al. IC40+59 Combined limit IC40+59 Guetta et al. x5? Neutrino Energy (GeV) [modified from Abbasi et al. 12]

27 Here, t H is the age of the Universe, and the factor ζ = 0.5 spectrum observed ζ 0.5 incorporates a correction due to redshift of the cosmic-ray d evolution of the star formation rate relative to its presentday value. (and The value acceleration) of ζ 0.5 1appliestoactivitythat in dense starburst galaxies > 1GeVphotonflu The inferred excess intense CR interactions traces the cosmic star formation history [6]. Note that cutoff/break feature (0.1 1) PeV at the CR knee (of these galaxies), the flavor oscillations would convert the pion decay flavor ratio, ν e : ν µ : ν τ =1:2:0to1:1:1[11],sothat butcosmic-rays very ar uncertain smaller than the va cosmic-ray distribu plot shows muon Φ νe neutrinos = Φ νµ = Φon ντ = production Φ ν /2. (3/2 of total) index of cosmic-ray the local one [27]. T 5 in SNe is inferred t p =2.1 ± 0.1 over TeV, based o 6 (e.g. [28]). AMANDA(ν ); Baikal(ν ) µ e For a steeply falli E 2,theproductio nated by protons o 7 WB Bound cosmic-ray knee c Star Bursts ogy with the Gala rays, we expect the C) Starburst galaxies E 2 ν Φ ν [GeV/cm2 s sr] km 2 Eν 2 ΦSB ν 7 (E ν / Atmospheric 1 km 2 GZK up to 0.1 PeV.In 9 trum for starburst g E ν [GeV] than in the Galaxy proton spectrum a [Loeb steeper & Waxman 06] proton prod FIG. 1: The shaded region brackets the range of plausible choices for the spectrum of the neutrino background. Its upper boundary is obtained for a power-law index p = 2 of time. Since both afasterdeclinewit t

28 d) Cosmogenic neutrinos cos-mo-gen-ic (adj.): produced by cosmic rays but this is true for all high-energy neutrinos... more specifically: not in the source or atmosphere, but during CR propagation most plausibly via pion production in pγ interactions, e.g. p + γ bgr n + π + π + µ + ν µ & µ + e + ν µν e pγ / pp (e.g. Centaurus A) propagation

29 d) Cosmogenic neutrinos Greisen-Zatsepin-Kuzmin (GZK) interactions of ultra-high energy CRs with cosmic microwave background (CMB) [Greisen 66;Zatsepin/Kuzmin 66] GZK -neutrinos at EeV energies from pion decay [Berezinsky/Zatsepin 69] three neutrinos (ν µ/ ν µ/ν e) from π + : E νπ 1 4 x Ep 1 20 Ep one neutrino from neutron decay: mn mp E p 3 E p m n log E dn/de, per cm 2.s.ster log E dn/de, per cm 2.s.ster W&B E νe E ν, ev FIG. 4. Fluxes of electron [Engel, neutrinos Stanev (dashed & Seckel 01] lines) and antineutrinos (dotted lines) generated in propagation of protons are shown in the upper panel. The lower panel shows the fluxes of muon neutrinos and antineutrinos. Solid lines show Markus Ahlers (UW-Madison) Multi-messenger aspects of the the IceCube sum excess of neutrinos and antineutrinos. February 27/28, The 2014 shaded band ν e ν µ tr th ar ar b p a ar h n su sh A ti b ti of fa th of ti a) or b th tr h th sp se ca

30 d) Cosmogenic neutrinos Greisen-Zatsepin-Kuzmin (GZK) interactions of ultra-high energy CRs with cosmic 5 microwave background (CMB) [Greisen 66;Zatsepin/Kuzmin 66] -4 RICE(2012) ANITA-II(20) 13 GZK -neutrinos 4 at EeV energies from pion decay [Berezinsky/Zatsepin 69] max z 3 three neutrinos (ν µ/ ν µ/ν e) from π + : 68% C.L. E νπ 1 4 x Ep 1 90% C.L. 20 Ep m sr -1 ] s -1-2 ) [GeV cm ν φ(e E 2 ν PAO(2012) ν τ limit x3 IceCube2012 Cosmogenic ν models Engel et al. Kotera et al. (FRII) Ahlers et al. (max) Ahlers et al. (best) Yoshida et al. FIG. 8. Constraints on the UHECR source evolution parameters of m and zmax with the present analysis. The semianalytic formulation [4] estimates the neutrino flux for calculating the limit shown here. The area above mn mp E νe E p 3 the solid lines is excluded at the quoted confidence level. E p m n one neutrino from neutron decay: CMB photons produces a bulk of neutrinos with energies much higher than 0 PeV which should have been detected because of the significantly larger effective area at 6 8 log (E /GeV) ν [IceCube 13] FIG. 9. All flavor neutrino flux differential 90% C.L. upper limit evaluated for each energy with a sliding window of one energy decade from the present IceCube EHE analysis including the IceCube exposure from the previously published result (IC40) [9]. All the systematic errors are included. Various model predictions (assuming primary protons) are shown for comparison; Engel et al. [7], Kotera et al. [17], Ahlers et

31 d) Cosmogenic neutrinos IC excess (x3) IC excess (x3) [Decerpit & Allard 11] neutrino flux depend on source evolution model (strongest for FR-II ) and EBL model (highest for Stecker model) Stecker model disfavored by Fermi observations of GRBs strong evolution disfavored by Fermi diffuse background

32 e) GZK neutrinos from heavy nuclei E 3 J [GeV 2 cm 2 s 1 sr 1 ] 3 2 HiRes I&II (E/1.2) Auger p source Fe source E 2 J [GeV cm 2 s 1 sr 1 ] Fermi-LAT IceCube (IC40) p source Fe source E [GeV] E [GeV] UHE CR emission toy-model: 0% proton: n = 5 & z max = 2 & γ = 2.3 & E max = 20.5 ev 0% iron: n = 0 & z max = 2 & γ = 2.3 & E max = ev Diffuse spectra of cosmogenic γ-rays (dashed lines) and neutrinos (dotted lines) vastly different. [MA&Salvado 11]

33 e) GZK neutrinos from heavy nuclei nucleon spectrum for observed mass number A obs: J min N (E N) = A 2 obsj CR(A obse N) lower limit by indefinite back-tracking of nuclei dependence on cosmic evolution of sources: no evolution (dotted) star-formation rate (solid) generalization to arbitrary composition via JN min (E N) = i f i(a ie N)A 2 i J CR(A ie N) E 2 J [GeV cm 2 s 1 sr 1 ] IC-86 (yr) p He N Si Fe HiRes TA Auger ARA-37 (3yr) E [GeV] [MA&Halzen 12]

34 e) GZK neutrinos from heavy nuclei nucleon spectrum for observed mass number A obs: J min N (E N) = A 2 obsj CR(A obse N) lower limit by indefinite back-tracking of nuclei dependence on cosmic evolution of sources: no evolution (dotted) star-formation rate (solid) generalization to arbitrary composition via JN min (E N) = i f i(a ie N)A 2 i J CR(A ie N) E 2 J [GeV cm 2 s 1 sr 1 ] IC-86 (yr) p@0eev: 0% % 1% HiRes TA Auger SFR evolution ARA-37 (3yr) E [GeV] [MA&Halzen 12]

35 f) γ-ray associations (isotropic) IceCube-equivalent diffuse γ-ray flux: E γj γ(e γ) e λγγ d 2 K 1 3 ν α E νj IC να (E ν) absorption length λ γγ via γγ e + e effect strongest for CMB in PeV range: λ γγ kpc plot shows distance d from 8.5 kpc (GC) to 30 kpc strong constraints of isotropic diffuse Galactic emission from γ-ray observatories [Gupta ] E 2 Jγ [GeV cm 2 s 1 sr 1 ] GRAPES-3 HEGRA IC-40 (γ) GAMMA UMC EAS-TOP KASCADE CASA-MIA kpc 9 20kpc 30kpc Eγ [TeV] [MA & Murase ]

36 f) γ-ray associations (isotropic) 90 o o 13 1 Galactic Plane Northern Hemisphere Southern Hemisphere o IC-86 (γ) IC-40 (γ) CASA-MIA HAWC 27 5 Galactic -180 o 15 events lie in TeV-PeV blind spot [MA & Murase ] one PeV event ( Ernie ) within of PeV γ-ray warm spot [IceCube 12]

37 g) γ-ray associations (Galactic Plane) diffuse γ-ray emission from CR propagation ( b < 2 ) supernova remnants (SNR): R SN 0.03yr 1 E ej 51 erg N SNR 1200 hypernova remnants (HNR): R HN 0.01R SN E ej 52 erg N HNR 20 flux concentrated in Galactic Plane: J 50% for b < 5 J 30% for b < however, this does not account for local fluctuation [MA & Murase ] E 2 Jγ [GeV cm 2 s 1 sr 1 ] supernova remnants ( b < 2 ) hypernova remnants ( b < 2 ) diffuse cosmic rays ( b < 2 ) HiSCORE (5yrs, b < 2 ) LHAASO (1yr, b < 2 ) HAWC (3yrs, b < 2 ) CTA (0h, b < 2 ) HEGRA ( b < 5, 0 < l < 255 ) HEGRA ( b < 5, 20 < l < 60 ) UMC ( b <, 30 < l < 220 ) IC-40 (γ) ( < b < 5, 280 < l < 330 ) GRAPES-3 ( b < 2, 20 < l < 55 ) GRAPES-3 ( b < 2, 140 < l < 225 ) EAS-TOP ( b < 5, l [40,111 ] [134,205 ]) Tibet ( b < 2, 20 < l < 55 ) Tibet ( b < 2, 140 < l < 225 ) CASA-MIA ( b < 5, 50 < l < 200 ) Milagro ( b < 5, 40 < l < 0 ) Milagro ( b < 2, l [30,65 ]([65,85 ])) Milagro ( b < 2, l [85,1 ]([136,216 ])) E γ [TeV]

38 g) γ-ray associations (Galactic Plane) EAS-TOP 13 UMC EAS-TOP IC-40 (γ) 28 4 latitude b Tibet 5 GRAPES CASA-MIA HEGRA Tibet HEGRA GRAPES Milagro 5 Milagro longitude l on-source search regions of TeV-PeV diffuse γ-rays from Galactic Plane no significant overlap [MA & Murase ]

39 h) γ-ray associations (extragalactic pp) CMB interactions (solid lines) dominate in casade: inverse Compton scattering (ICS) e ± + γ CMB e ± + γ pair production (PP) γ + γ CMB e + + e PP in IR/optical background (red dashed line) determines the edge of the spectrum. this calculation: Franceschini et al. 08 interaction length [Mpc] E [GeV] Γ 1 Γ 1 PP (CMB) PP (IR/opt.) Γ 1 ICS (CMB) E/b syn (pg) Rapid cascade interactions produce universal GeV-TeV emission (almost) independent of injection spectrum and source distribution. cascade bound for neutrinos [Berezinsky&Smirnov 75]

40 h) γ-ray associations (extragalactic pp) CMB interactions (solid lines) dominate in casade: diffuse γ-ray background inverse Compton scattering (ICS) e ± + γ CMB e ± + γ 5 pair production (PP) γ + γ CMB e + + e PP in IR/optical background (red dashed line) determines the edge of the spectrum. this calculation: Franceschini et al. 08 E 2 J [GeV cm 2 s 1 sr 1 ] Fermi-LAT (Abdo et al. ) Fermi-LAT fit: E 2.4 EGRET (Sreekumar et al. 98) EGRET fit: E E [GeV] Rapid cascade interactions produce universal GeV-TeV emission (almost) independent of injection spectrum and source distribution. cascade bound for neutrinos [Berezinsky&Smirnov 75]

41 h) γ-ray associations (extragalactic pp) neutrino flux in pp scenario follows CR spectrum E Γ low energy tail of GeV-TeV neutrino/γ-ray spectra constraint by extragalactic γ-ray background extra-galactic emission: Γ 2.2 Galactic emission: Γ 2.0 limits insensitive to redshift evolution effects [Murase, MA & Lacki 13]

42 i) Fermi Bubbles 26 two extended GeV γ-ray emission regions close to the Galactic Center [Su, Slatyer & Finkbeiner ] 3.0 Fermi 1-5 GeV hard spectra and relatively uniform emission some correlation with WMAP haze and X-ray observation model 1: hadronuclear interactions of CRs accelerated by star-burst driven winds and convected over few 9 years [Crocker & Aharonian 11] model 2: leptonic emission from 2nd order Fermi acceleration of electrons [Mertsch & Sarkar 11] probed by associated neutrino production [Lunardini & Razzaque 12] kev cm -2 s -1 sr [Su, Slatyer & Finkbeiner 11] Rosat Band 6 and 7-5

43 i) Fermi Bubbles Fermi Bubbles 17 Bubble o 13 1 Galactic Plane Northern Hemisphere Southern Hemisphere o Galactic -180 o

44 i) Fermi Bubbles 6 B Fermi Bubbles? sin(declination) E 2 Jγ [GeV cm 2 s 1 sr 1 ] LHAASO (1yr, FB) HAWC (3yrs, FB) CTA (0h, FB) ANTARES (FB, prel.) GRAPES-3 (FB) CASA-MIA (FB) Fermi Bubble IceCube (FB) small zenith excess in IceCube excess (but not significant) E γ [TeV] Galactic Center source(s) of extended source, e.g. Fermi Bubbles? γ να [MA & Murase ] [Finkbeiner, Su & Slatyer ] FB excess in agreement with GeV-PeV neutrino & γ-ray observations and limits assuming Γ 2.2

45 j) UHE CR associations neutrino and CR nucleon relation: 1 EνQ 2 να (E ν) 1 f πk π ENQ 2 N(E N) K π α UHE CR proton emission rate density: E 2 pq p(e p) (1 2) 44 erg Mpc 3 yr 1 cosmic evolution, e.g. H 0(z) = Θ(2 z) or (1 + z) 3.4 z < 1, H SFR(z) = N 1 (1 + z) < z < 4, N 1 N 4 (1 + z) 3.5 z > 4 [Hopkins&Beacom 98] E 2 Qp [erg Mpc 3 yr 1 ] H0 HSFR 11 E [GeV] [MA&Halzen 12]

46 j) UHE CR associations diffuse extragalactic neutrino emission: J ν(e ν) = 1 4π per flavor flux (ξ z and K π 1 2): WB bound: f π 1 0 dz H(z)Qν((1 + z)eν) H(z) EνJ 2 ξ zk π ν(e ν) f π (2 4) 8 GeV cm 2 s 1 sr 1 + K π f π 1 requires efficient pion production how to reach E max 20 ev in environments of high energy loss? two-zone models: acceleration + CR calorimeter? starburst galaxies galaxy clusters holistic CR models: universal time-dependent CR sources? [Waxman&Bahcall 98] [Loeb&Waxman 06] [Berezinsky,Blasi&Ptuskin 96;Beacom&Murase 13] [Parizot 05;Aublin&Parizot 06;Katz,Waxman,Thompson&Loeb 13]

47 Outlook The IceCube excess marks the birth of HE neutrino astronomy! background probability 4.1σ: 4 in 0000 What s next: 3rd year of data to be un-blinded & 4th year of data collected by May 2014 Do we see individual sources or just a diffuse background? What can we learn from spectrum (in particular a possible PeV-ish break) and flavor composition? Is the corresponding CR population responsible for UHE CRs? Neutrino astronomy also closes in on cosmogenic neutrino fluxes. Will we already see the first hints with IceCube or do we have to wait for future EeV neutrino upgrades (ARA, ARIANNA,... )?

48 Appendix Appendix

49 Cosmic ray spectrum 4 Knee sr -1 ] s -1 m [GeV F(E) 2.6 E Grigorov JACEE MGU Tien-Shan Tibet07 Akeno CASA-MIA HEGRA Fly s Eye Kascade Kascade Grande 2011 AGASA HiRes 1 HiRes 2 Telescope Array 2011 Auger E [ev] 18 Ankle [from Particle Data Group 12] Appendix

50 extragalactic Cosmic ray spectrum Appendix sr -1 ] s -1 m [GeV F(E) 2.6 E Grigorov JACEE MGU Tien-Shan Tibet07 Akeno CASA-MIA HEGRA Fly s Eye Kascade Kascade Grande 2011 AGASA HiRes 1 HiRes 2 Telescope Array 2011 Auger Knee 16 galactic 17 E [ev]? 18 Ankle [from Particle Data Group 12]

51 Milky Way and Local Arm 60 o 240 o Close-by sources in the Local Arm can show up as high-latitude hot spots! Appendix

52 Glashow resonance resonant interactions with in-ice electrons: ν ee W X hadronic (70%) or leptonic (30%) decay pp (top plot) and pγ (bottom plot) with different flavor ratios and E 2 -flux [Bhattacharya, Gandhi, Rodejohann & Watanabe 11] early Glashow-excitement after Neutrino 2012, Kyoto [Barger, Learned & Pakvasa ] [Bhattacharya et al ] Where are the Glashow events? flavor composition and spectral features [Laha et al ; Anchordoqui et al ] [He et al ; Winter ] Figure 4: The shower spectrum for pure pp sources, x = 1. We have neglected eve from the interactions νee νee and νee ντ τ which contribute, comparatively, a v tiny fraction of events to the spectrum. (neutral) current. The tau contribution ντn + ντ N (CC) is irrelevant at the resona energy bin since a tau with Eτ 2 PeV manifests itself as a track. The event rate νen + νen (CC) is given by Rate = 2π NAVeff deν [ σcc(νn) Φνe(Eν)+σCC( νn) Φ νe(eν)], (4 where σcc(νn/ νn) is the neutrino nucleon cross section which is cm 2 Eν =6.3 PeV [24]. For ναn + ναn (NC), the rate is calculated as Rate 2π NAVeff α=e,µ,τ E1/ y deν [ σnc(νn) Φνα(Eν)+σNC( νn) Φ να(eν)], (4 E0/ y Appendix for the shower energy between E0 and E1. Here y is the mean inelasticity which well described by the average value y =0.26 at PeV energies. The NC cross sect Figure 5: The shower spectrum at the resonant peak is 6 34 for pure cm 2 pγ sources, x = 0. We have neglected eve. In the NC process, only a part of the neutr from the interactions νee νee and νee ντ τ which contribute, comparatively, a v

53 Gamma-ray bursts (GRBs) CONTENTS Appendix

54 IC40+59 results Limits on neutrino emission coincident with 215 (85) northern (southern) sky GRBs between April 2008 and May 20 ( IC40+59 ). [Abbasi et al. 11; 12] Model-dependent limit for prompt emission model. Model-independent limit for general neutrino coincidences (no spectrum assumed) with sliding time window ± t from burst. Stacked flux below benchmark prediction of burst neutrino emission by a factor 3-4. [Guetta et al. 04] conversion to diffuse flux via cosmic GRB rate. Appendix string portion of the analysis, and the black dashed line labelled IC40159 r Guetta et al. showing the prediction for the full two-year dataset. The cosmic ( ray normalized Waxman-Bahcall flux 4,20 is also shown for reference as the pale n grey RESEARCH dashed line. LETTER 90% confidence upper limits on these spectra are shown as c solid lines, with the grey line labelled IC40 limit showing the previous IceCube model-dependent s result 6 and the black IC401IC59 Combined line showing the result from the 9 full dataset 8 (this work). The predicted neutrino flux, when normalized to the a c-rays 6,9, is proportional Waxman and Bahcall to the ratio of energy in protons to that in electrons, 0 G which are presumed IC-40 responsible for the c-ray emission (ep/ee, here the standard 1 IC40 Guetta et al. p ). The flux shown is slightly modified 6 from the original calculation 9. Wn (left IC40+59 Combined c vertical axis) limit is the average neutrino flux at Earth, obtained by scaling the T summed predictions IC40+59 Guetta from the bursts in our sample (Fn, right vertical axis) by et al. the global GRB rate (here 667 bursts yr 21 fi ; ref. 7). The first break in the neutrino b1 spectrum is related to the break in the photon spectrum measured by the to satellites, 9 and the threshold for photo-pion production, whereas the second li break corresponds to the onset of synchrotron losses of muons and pions. 1 Not s all of the parameters used in the neutrino spectrum calculation are measurable a from every burst. In such cases, benchmark values 7 were used for the 1 d unmeasured parameters. Data shown here were taken from the result of the d model-dependent analysis. ( Neutrino energy (GeV) ta Figure 1 Comparison of results to predictions based on observed c-ray a spectra. The summed flux predictions normalized to c-ray spectra 6,9,19 are model-independent in shown as a function of neutrino energy (E) in dashed lines, with the dark grey a dashed 24line labelled IC40 Guetta et al. showing the flux prediction for the 40- Figur string portion of the analysis, and the black dashed line labelled IC ( 90% Upper limit ray pm Guetta et al. showing 90% Sensitivity the prediction for the full two-year dataset. The cosmic 20 ( IC40 ray normalized Waxman-Bahcall flux 4, is also shown for reference as the pale neutr p grey dashed line. 90% confidence upper limits on these spectra are shown as 0.30 comp solid lines, with the grey line labelled IC40 limit showing the previous IceCube s 16 solid result 6 and the black IC401IC59 Combined line showing the result from the t Event % c full dataset (this work). The predicted neutrino flux, when normalized to the e analy c-rays12 6,9, is proportional to the ratio of energy in protons to that in electrons, 0.20 GRBs lo which are presumed responsible for the c-ray emission (ep/ee, here the standard powe ). The 8 flux shown is slightly modified 6 from the original calculation 9. Wn 0.15(left corre vertical axis) is the average neutrino flux at Earth, obtained by scaling the s The m summed predictions from the bursts in our sample (Fn, right vertical axis) 0.by T the global GRB rate (here 667 bursts yr 21 first b 4 ; ref. 7). The first break in the neutrino t been spectrum is related to the break in the photon spectrum measured by the 0.05 to the A satellites, and the threshold for photo-pion production, whereas the second limits c break corresponds 0 to the onset 0 of synchrotron 1,000 losses of muons and,000 pions. 0 Not showc all of the parameters used in the neutrino Δt (s) spectrum calculation are measurable all mo from every burst. In such cases, benchmark values 7 were used for the fl depen unmeasured Figure 2 Upper parameters. limitsdata on Eshown 22 power-law here were muon takenneutrino from the result fluxes. oflimits the p decay E 2 ν (GeV cm 2 s 1 sr 1 ) Φ Muon neutrino events 21 E 2 F ν (GeV cm 2 ) E 2 F ν (GeV cm 2 ) E 2 ν Φ ν (GeV cm 2 s 1 sr 1 )

55 IC40+59 results Muon neutrino events 24IceCube 90% Upper limit below benchmark % Sensitivity 20diffuse models normalized to UHE CR data. [Waxman&Bahcall 03; Rachen et al. 98] IceCube s results challenge GRBs 0.2 as the sources of UHE CRs! Event Limit on burst neutrino emission 0 depends s on 0 s neutrino 00 break s energy s ε b Γ 2 t (s) (break in optical depth). ficiency, for example by modifying the physics included in the predictions 19,20 or by increasing the bulk Lorentz FIG. 2. boost Limits factor on E. 2 Increasing fluxes fromincreases the model-independent the proton energy asthreshold a function from analysis Results forof pion model-dependent theproduction size of thein time the observer window frame, t, calculated thereby using reducing the Feldman-Cousins the neutrino flux method due to analysis translate into bounds 17 the. The lower leftpro- ton density the total at higher number energies. of expected Astrophysical µ events of lower while GRB limits the y- axis shows right-hand parameters. on are vertical established axis by thepair same production as the right-hand [Guetta arguments etvertical al. 04],but axis inthe Fig. upper 1. Alimit timeiswindow less clear. of Although t impliesit observed is possible events that arrivingmay between take tvalues seconds of up before to 00 the burst in some and unusual t afterward. bursts, The variation the average of the value upper is likely limitlower with(usually t reflects assumed statistical to be fluctuations Neutron aroundin 300 the 6, emission observed ) and thebackground non-thermal models rate, gamma-ray largely as well as spectra the presence ruled fromof the individual out. bursts [MA, set events a Gonzalez-Garcia weak of varying constraint quality. that & Halzen 11] The event 21. at 30 For seconds all considered (Event 1) models, is consistent with uniform with background fixed protonand content, to be verya cosmic-ray high average airvalues shower. of are required to be believed compatible with our limits (Figs. 3, 4). In the case of models where cosmic rays escape from E 2 muon the GRB neutrino fireball fluxes as neutrons at Earth 9,11, as the a neutrons function and of the neutrinos are created in the same p interactions, Appendix directly E 2 F ν (GeV cm -2 ) E 2 Φ ν (GeV cm -2 s -1 sr -1 ) IC40+59 Allowed (90% CL) IC40+59 Allowed (95% CL) Waxman (2003) Rachen et al. (1998) Ahlers et al. (2011) Neutrino break energy ε b (GeV) 20 FIG. 3. Limits from the model-independent analysis in comparison to theoretical predictions relating GRB neutrino fluxes to the cosmic line (this result) ray flux. Data are taken from the time window corresponding to the median duration of the GRBs 3 years IC86 in our catalog ( t = 28 seconds). Spectra are represented as broken power laws ( {E 1 / b,e < b; E 2,E > b}) with a break energy b corresponding to the resonance for p interactions in the frame of the shock. The muon flux in IceCube is dominated by neutrinos with energies around the first break ( b). As such, the upper break, due to synchrotron losses of +, has been neglected, as its presence or absence does not contribute significantly to the muon flux and thus does 350 not 400have 450a significant e ect 600 on 650the700 presented limits. The neutrino break energy b is related to the bulk Lorentz factor ( b / 2 ). All of the models shown assume FIG Limits The value on GRB of energy corresponding protons, as to a function 7 GeV of is the > E 2 F ν (GeV cm -2 ) 5 4

56 GRB flux normalization Neutrino predictions depend on model and normalization: A GRB as the source of UHE CRs? calculate the pion energy fraction f π in pγ interactions normalize to UHE CRs [Waxman & Bahcall 97] A GRB as the source of UHE CR neutrons? independent of f π normalize to UHE CRs [Rachen & Mészáros 98; MA, Gonzalez-Garcia & Halzen 11] B GRB as one source of (UHE) CRs? use bolometric energy arguments about internal energy densities U in shock U B = ɛ BU tot U e = ɛ eu tot U p = ɛ pu tot by construction, ɛ B + ɛ e + ɛ p 1, but otherwise not well constrained calculate the pion energy fraction f π in pγ interactions normalize to CRs in individual bursts, U p = (ɛ p/ɛ e)u burst [Guetta et al. 04;He et al. 12] Appendix

57 GRB model-dependence The parameters Γ i, ɛ p and ɛ e are in general fudge-factors; some indirect observation by GRB afterglow emission. Model hierarchy: A B or not B not A Heavy nuclei acceleration in internal shocks? issues for model A; large internal shock radii and/or large Lorentz factors needed to reach UHEs [Wang,Razzaque&Meszaros 08;Murase et al. 08] generally lower neutrino luminosity due to limited photon density Diffuse limits have also dependence on the stochasticity of the tested GRB ensemble. [Baerwald,Hümmer&Winter 11] Revised calculations of pion fraction f π produce lower values than the standard parametrization [Li 11; Baerwald,Hümmer&Winter 11;He et al. 12] CR production via neutron emission (model A ) relates neutrinos and CR protons independent of the absolute value f π; scenario largely ruled out by IC [MA/Gonzalez-Garcia/Halzen 11] Appendix

58 Extra-galactic background light (EBL) λ [µm] E u(e) [erg cm -3 ] Finke et al. (20) Kneiske et al. (2004) Franceschini et al. (2008) Gilmore et al. (2008) Razzaque et al. (2009) Stecker et al. (2006) E [ev] 1 0 E I(E) [nw m -2 sr -1 ] [Finke et al. ] BL models, measurements, optical-uv background and constraints. gives PeV Seeneutrino Finke peak et al. for details and re Appendix

59 Cosmogenic neutrinos & gamma-rays GZK interactions produce neutral and charged pions p + γ CMB n + π + /p + π b BH p /E b π p/e H 0 Bethe-Heitler (BH) pair production: p + γ CMB p + e + + e BH is dominant energy loss process for UHE CR protons at GeV. energy loss rate [Mpc 1 ] 2 3 EM components cascade in CMB/EBL and contribute to GeV-TeV γ-ray background E [GeV] [Berezinsky&Smirnov 75] Appendix

60 Cosmogenic neutrinos from EBL E 2 J [GeV cm 2 s 1 sr 1 ] E 2 J [GeV cm 2 s 1 sr 1 ] Emin = 17.5 ev HiRes I&II Fermi LAT p (best fit), (99% C.L.) (99% C.L.) Emin = 18.5 ev HiRes I&II Fermi LAT p (best fit), (99% C.L.) (99% C.L.) maximal cascade maximal cascade Emin = 18 ev HiRes I&II Fermi LAT p (best fit), (99% C.L.) (99% C.L.) Emin = 19 ev HiRes I&II Fermi LAT p (best fit), (99% C.L.) (99% C.L.) maximal cascade maximal cascade E [GeV] E [GeV] [MA, Anchordoqui, Gonzalez-Garcia, Halzen & Sarkar 11] Figure 4: Comparison of proton, neutrino and -ray fluxes for di erent crossover energies. We show the best-fit values (solid lines) as well as neutrino and -ray fluxes within the 99% C.L. with minimal and maximal energy density (dashed lines). The Appendix values of the corresponding model parameters can be found in Table. 1. The dotted line labeled maximal cascade indicates

61 Propagation of CR nuclei 52 Ti 53 V 54 Cr 55 Mn 56 Fe 49 Ca 50 Sc 51 Ti 52 V 53 Cr 54 Mn 55 Fe fast photo-disintegration of nuclei (mass number A = N + Z) beyond the giant dipole resonance (GDR): λ GDR 4 A Mpc stable nuclei N longlived nuclei PSB-chain Z 48 Ca 49 Sc 50 Ti 51 V 52 Cr 53 Mn 54 Fe 46 K 47 Ca 48 Sc 49 Ti 50 V 51 Cr 52 Mn 53 Fe 44 Ar 45 K 46 Ca 47 Sc 48 Ti 49 V 50 Cr 51 Mn 52 Fe 43 Ar 44 K 45 Ca 46 Sc 47 Ti 48 V 49 Cr 42 Ar 43 K 44 Ca 45 Sc 46 Ti 47 V 48 Cr 40 Cl 41 Ar 42 K 43 Ca 44 Sc 45 Ti 38 S 39 Cl 40 Ar 41 K 42 Ca 43 Sc 44 Ti 37 S 38 Cl 39 Ar 40 K 41 Ca 36 S 37 Cl 38 Ar 39 K 40 Ca 35 S 36 Cl 37 Ar 38 K 32 Si 33 P 34 S 35 Cl 36 Ar strong influence of mass composition at very high energy BUT: conserves total number of nucleons with nucleon energy E/A! 31 Si 32 P 33 S 28 Mg 29 Al 30 Si 31 P 32 S 27 Mg 28 Al 29 Si 30 P 24 Ne 25 Na 26 Mg 27 Al 28 Si 24 Na 25 Mg 26 Al 22 Ne 23 Na 24 Mg 21 Ne 22 Na 18 O 19 F 20 Ne 17 O 18 F 14 C 15 N 16 O 17 F 13 C 14 N 15 O Be 11 B 12 C 13 N 14 O Neutrino production (mostly) via γ-nucleon interaction! Appendix 9 Be B 11 C 7 Li 6 Li 7 Be T 4 He D 3 He p [Puget/Stecker/Bredekamp 76;MA/Taylor ]

62 Approximate scaling law of energy densities ω ν i A 2 γ E i thq 2 i(e th) i 2 γ i } {{ } composition zmax 0 dz (1 + z)n+γ i 4 H(z) } {{ } evolution * disclaimer: source composition Q i with mass number A i and index γ i applies only to models with large rigidity cutoff E max,i A i E GZK previous examples (z max = 2 & γ = 2.3): 0% proton: n = 5 & E max = 20.5 ev ω γ % iron: n = 0 & E max = ev ω γ relative difference: 82. Appendix

63 Nucleon cascade Observed composition is result of source composition and nucleon cascades. A+5 Backtracking conserves energy per nucleon. Bethe-Heitler (BH) loss breaks this approximation b A,BH(E) Z 2 b p,bh(e/a) A+4 Minimal cosmogenic neutrino production from fit to Auger data assuming: maximal backtracking minimal BH loss p He A minimal nucleon emissivity Appendix

64 Nucleon cascade Observed composition is result of source composition and nucleon cascades. A+5 Backtracking conserves energy per nucleon. Bethe-Heitler (BH) loss breaks this approximation b A,BH(E) Z 2 b p,bh(e/a) A+4 Minimal cosmogenic neutrino production from fit to Auger data assuming: maximal backtracking minimal BH loss p He A minimal nucleon emissivity Appendix

65 bution of neutrino events that were detected, showing that the in neutrino angular acceptance spans a range from 5 below ne the horizon to 45 above the horizon, more than 6 steradi- ac ta A Auger Observatory, while probing a similar energy sta TABLE ARA, II: does Expected notnumbers have of asevents highnν afrom neutrino several UHE sensitivity neutrino models, comparing published values from the 2008 ANITA-II asa flight marily with predicted a UHECR events for instrument. a three-year exposure ARAforwill ARA-37. complem m other instruments by making high sensitivity obser tio themodel 0.1- & references EeV energy Nν: range, ANITA-II, matchingara, the peakth (2008 flight) 3 years pected cosmogenic neutrino fluxes. Cosmogenic neutrinos from heavy ans of solid nuclei angle. Yuksel & Kistler 07 ESS 01 strong Kotera et al. max ESS 01 baseline Ahlers et al. 11 re Baseline cosmogenic models: w ar Protheroe & Johnson 1996 [27] al Engel, Seckel, Stanev 2001 [28] ca Kotera,Allard, & Olinto 20 [29] V. CONCLUSIONS Strong source evolution models: ac Engel, Seckel, Stanev 2001 [28] Th We Kalashev havet al. described 2002 [30] the design5.8 and initial 146 perfo tin Barger, Huber, & Marfatia 2006 [32] a new ultra-high energy neutrino detector at the su S Yuksel & Kistler 2007 [33] fe themixed-iron-composition: 16-antenna, self-triggering ARA-testbed, which tim Kotera et al. mid fidelity Ave et prototype al [34] for future ARA0.01 detector6.6 stations. th Kotera et al. low Stanev 2008 [35] operation extending well into the the extreme therma Ave et al. 07 Fe mix Kotera, Allard, & 20 [29] upper al ANITA II (20) mentkotera, of the Allard, austral & Olintowinter 20 [29] indicates lower that radio-freque 4.1 te IceCube 40 (2011) ference Models constrained is infrequent by Fermi cascade and has bound: only a slight impact on am Auger (2009) for our Ahlerstestbed et al. 20 [36] detector, which is0.09 closest20.7 of any fu m ARA 37 3 yrs projected Waxman-Bahcall (WB) fluxes: tu stations to the primary sources of interference at WB 1999, evolved sources [37] PoleWB station. 1999, standard Other [37] than brief periods 0.5 of sporadic 27 int tin the baseline radio noise levels are dominated by the [ARA 11] mal In Table noiseii floor we give ofexpected the ambient neutrinoice, event and totals thefrom thermal a usn wide range of currently allowed cosmogenic neutrino models tim not appear to be correlated to wind velocity. We hav for ARA in three years of operation, compared to recent published orders stratexpectations theof ability magnitude!) for the to best maintain current limits cover impulse to date, various trigger from thesensi FIG. 27: Compilation of sensitivity estimates from existing instru- ANITA-II level close flight to [3]. the It isthermal evident that noise. ARA-37We willhave extenddemons in Best-fit range of GZK neutrino predictions ( two ments, published limits, and a range evolution of GZK neutrino models models, andalong sourcesensitivity compositions. above ANITA-2 s sensitivity by factors of two orders of magnitude or more. For strong-source-evolution and impulse propagation of more than 3 km slant rang with the expected 3 year ARA sensitivity. baseline the South models, Pole ARA-37 ice without detects between significant of order loss 50 toofover signaltim c 200 Weevents haveindemonstrated three years of operation, inter-antenna enough to pulse establishtiming the pr m Appendix basic order characteristics 0 ps, implying of the energyangular spectrum and resolutions source arrival which Th