High energy neutrino astronomy What we have learned

High energy neutrino astronomy What we have learned and the way forward Eli Waxman Weizmann Institute of Science Feb. 2017

log [dn/d. E] The main driver of HE n astronomy: The origin of Cosmic Rays E-2. 7 E-3 Detection: Space (direct) Ground (Air-showers indirect) Open Q’s Composition: Protons Heavier (C, N, O, Fe) Lighter (Heavier? ) Composition? Confinement: Galactic G/XG transition? 1 Sources: X-Galactic 103 SN remnants(? ) 106 1010 ? ? E [Ge. V] Sources? Acceleration? [Reviews: Helder, et al. 12; Lemoine 13]

The acceleration challenge • At the focus of HE Astro. Radio- g-ray observations Particle acceleration

UHE, >1010 Ge. V, CRs J(>1011 Ge. V)~1 / 100 km 2 year 2 p sr 3, 000 km 2 Auger: 3000 km 2 Fluorescence detector Ground array

UHE: Air shower composition constraints Auger 2010 2015 Fe N He p Hi. Res Stereo 2010 Hi. Res 2005

UHE: Air shower composition constraints Inconclusive • Auger/Hi. Res discrepancy. • Uncertainties in extrapolation to ECM>100 Te. V (not spanned by models), 25% cross-section & elasticity [Ulrich, Engel & Unger 11] Exp. sys. uncertainty. • Primary mass & Extrapolation to >100 Te. V effects are degenerate. • Discrepancies between shower models and data. [Auger Dec 16]

>1010 Ge. V spectrum: a hint to p’s cteff [Mpc] GZK

UHE p-sources & GRB’s UHE p source requirements GRBs’ characteristics Transient 1 -100 s long [EW 95]

A mixed composition? N p He Fe [Auger Dec 16]

High energy n telescopes • Detect HE n’s from p(A)-p/p(A)-g charged pions n’s, p + m+ + n m e + + n e + n m , En/(EA/A)~0. 05. • Goals: – Identify the sources (no delay or deflection with respect to EM), – Identify the particles, – Study source/acceleration physics, – Study n/fundamental physics.

HE n: predictions •

HE n: predictions p n HE p’s lose their energy in star-forming host galaxy tgp(pp)>1 UHE p’s escaping their sources Observed UHE CRs “Calorimetric” n’s 106 WB Bound 108 CMB interaction n’s 1010 E [Ge. V]

Bound implications: >1 Gton detector (natural, transparent) Fermi 1/Gt yr Rate ~ (EF)Nns(E), s~E Rate ~ (E 2 F)M 2 flavors,

AMANDA & Ice. Cube Completed Dec 2010

Looking up: Vetoing atmospheric neutrinos [Schoenert, Gaisser et. al 2009] • Look for: Events starting within the detector, not accompanied by shower muons. • Sensitive to all flavors (for 1: 1: 1, nm induced m~20%). • Observe 4 p. • Rule out atmospheric charmed meson decay excess: Anisotropy due to downward events removal (vs isotropic astrophysical intensity). [Cartoon: N. Whitehorn]

r 400 Te. V 1100 Te. V

Ice. Cube: 37 events at 50 Tev-2 Pe. V ~6 s above atmo. bgnd. [02 Sep 14 PRL] y m o n stro ra e w a n in e n A E 2 Fn =(2. 85+-0. 9)x 10 -8 Ge. V/cm 2 sr s =E 2 FWB= 3. 4 x 10 -8 Ge. V/cm 2 sr s (2 Pe. V cutoff? ). Consistent with Isotropy, ne: nm: nt=1: 1: 1 (p deacy + cosmological prop. ).

Status: Isotropy, flavor ratio

Status: Flux, spectrum WB E L E H PRL 115, 081102 (2015) • Excess below ~50 Te. V. If real, likely a new low E component (rather than a soft G=2. 5 spectrum). [e. g. Palladino & Vissani 16] • PRD 91, 022001 (2015) However, note: - F ~ 0. 01 FAtm. at low E, - Veto efficiency decreasing at low E, - Tension with Fermi data.

Ice. Cube’s (>50 Te. V) n sources • DM decay? Unlikely- chance coincidence with FWB. • Galactic? Unlikely. - Isotropy. - Fermi’s g-ray DGE intensity (all sky average) at 1 -100 Ge. V E 2 Fg~2 x 10 -7(E 0. 1 Te. V)-0. 7 Ge. V/cm 2 s sr, extrapolated to Ice. Cube’s energy E 2 Fn~2 x 10 -9(E 0. 1 Pe. V)-0. 7 Ge. V/cm 2 s sr << FWB. XG CR sources. Coincidence with FWB suggests a connection to the UHE sources.

Ice. Cube’s (>50 Te. V) n sources (a) Most natural (and predicted): XG UHE p sources, QE=Const. , residing in (starburst) “calorimeters”. Sources & calorimeters known to exit, no free model parameters. Main open question: properties of star-forming galaxies at z~1. (b) Q>>QUHE sources with tgp(pp)<<1, ad-hoc Q/QUHE>>1 & tgp(pp)<<1, to give (Q/QUHE) * tgp(pp)=1 over a wide energy range. (b) tgp(pp)<<1 p UHE (a) tgp(pp)>1 n IC n’s 106 108 1010 E [Ge. V]

A single cosmic ray source across the spectrum? Observed spectrum Generation spectrum Cosmic background From a past transient in the MW XG n’s XG CRs [Katz, EW, Thompson & Loeb 14] [From Helder et al. , SSR 12]

Fermi’s XG g-ray background [EGB] • [Murase & EW 16] Murase 14

Identifying the “calorimeters” •

Have we already seen the “calorimeters”? •

Identifying the sources •

Model predictions vs. observations UHE (>109 Ge. V) Prediction VHE Obs. Prediction Obs. Galactic Prediction Obs. ? (low statistical significance) (source subtraction uncertainty) (weak) LSS anisotropy ?

The way forward: I. GZK n’s • ARIANNA radio station J. Hoerandel

Auger’s UHE limit [<2013/6 data]

The way forward: UHE CR experiments • Telescope-Array x 4 (hybrid, ~Auger at the North). • Auger’ : Add scintillators for e/m to Identify primary mass for all events (not only hybrid), Use p fraction for “astronomy” (anisotropy, sources). Complete deployment by 2020. • Radio arrays, high duty cycle [e. g. Falcke & Gorham 03] [LOFAR-LORA Buitink et al. 2016 ]

The way forward: II. VHE n’s • IC Gen 2 KM 3 Ne. T

The way forward: III. HE n’s • 10 Gton n detector point source sensitivity [van Santen 2017] g ray telescopes’ sensitivity [Ohm 2017]

Future constraints from flavor ratios ! e r o f e tb i e on n‘s d e hav • Without "new physics", nearly single parameter (~fe @ source). • Few % flavor ratio accuracy [requires x 10 Meff @ ~100 Te. V] Relevant n physics constraints [even with current mixing uncertainties]. [Capozzi et al. 13] E. g. (for p decay) m/(e+t) = 0. 49 (1 -0. 05 Cos d. CP), e/t = 1. 04 (1+0. 08 Cos d. CP). [Blum et al. 05; Seprico & Kachelriess 05; Lipari et al. 07; Winter 10; Pakvasa 10; Meloni & Ohlsson 12; Ng & Beacom 14; Ioka & Murase 14; Ibe & Kaneta 14; Blum et al. 14; Marfatia et al. 15; Bustamante et al. 15…]

Short GRBs: multi-messenger prospects • The jets of short GRBs are believed to be driven by Neutron star mergers • Prospects for detection in Gravitational waves, Photons, Neutrinos. [Bartos et al. 11, 13; Bartos, Brady & Marka 13] Radio to gamma-ray “Afterglow” • Study Nuclear density matter, Jet “engines”, Particle acceleration.

Summary •

Backup Slides

1011 Ge. V: The acceleration challenge v R B v 2 R l =R/G (dt. RF=R/Gc)

UHE: Do we learn from (an)isotropy? • No significant anisotropy >4 x 1010 Ge. V. Galaxy density integrated to 75 Mpc Not a significant result: P(reject isotropy @ 95% CL with 600 events)=50%. [Kashti & EW 08] • Significant strong dipole at ~ 8 x 109 Ge. V. Near the Galactic plane. [Auger, Kampert 17] CR intensity map (rsource~rgal)

A note on prompt GRB n’s • In [EW & Bahcall 97] WB 10% 1% GRB 0. 1 1 E (Pe. V) [Ice. Cube 16]

Where is the G-XG transition? [Katz & EW 09]

Low Energy, ~10 Ge. V • Our Galaxy- using “grammage”, local SN rate • Starbursts- using radio to g observations Q/SFR similar for different galaxy types, d. Q/dlog e ~Const. at all e. [Katz, EW, Thompson & Loeb 14]

Are SNRs the sources of E<1 Pe. V CRs? p 0 decay signature [Ackermann et al. 13]. • So far, no direct evidence. • EM observations- ambiguous. • Modelling complex (interaction with molecular clouds). • p 0 interpretation Ep<100 Ge. V.

Acceleration: Collisionless shocks A (collisionless) shock fast, cold, un-magnetized plasma v 1 slow, hot (non-thermal) v 2<v 1 10 c/wp Collective plasma mediated scattering v 2<v 1 10 c/wp Energetic particle

Collisionless shocks: Plasma simulations 3 D, mp/me=1 1 D, mp/me=100, L=103 c/wp [Park et al. 15] 200 c/wp p 2 dn/dp 1/E 2 40 c/wp p=mpc

Particle acceleration in collisionless shocks • No basic principles theory. • Challenges: Self-consistent particle/B, Non linear with a wide range of temporal/physical scales. [Sironi, Spitkovsky & Arons 13]

p production: p/A—p/g • p decay ne: nm: nt = 1: 2: 0 (propagation) ne: nm: nt = 1: 1: 1 • p(A)-p: en/ep~1/(2 x 3 x 4)~0. 04 (ep e. A/A); - IR photo dissociation of A does not modify G; - Comparable particle/anti-particle content. • p(A)-g: en/ep~ (0. 1— 0. 5)x(1/4)~0. 05; - Requires intense radiation at eg>A ke. V; - Comparable particle/anti-particle content, ne excess if dominated by D resonance (dlog ng/dlog eg<-1).

Future experimental developments • IC extension • Mediterranean Km 3 Net (~5 x IC) • ARA & ARIANNA: Coherent radio Cerenkov, 108 to 1010 Ge. V

What is required for the next stage of the n astronomy revolution? • Ice. Cube’s detection rate (~1/yr @ E>1 Pe. V, ~10/yr @ E>0. 1 Pe. V) insufficient for precision spectrum, flavor ratio and (an)isotropy, and for source identification. Expansion of n telescopes Meff @ ~1 Pe. V to ~10 Gton (NG-Ice. Cube, Km 3 Net). • Wide field EM monitoring. • Adequate sensitivity for detecting the ~1010 Ge. V GZK n’s. HE g-ray telescopes will play a key role. •

Star forming galaxies: candidate CR calorimeters •

[Rev. Sci. Inst. ]

Me. V- Ge. V Achievements: Detection of solar and SN n’s, Tests of stellar structure and explosion models, n mass and oscillations. >100 Te. V Achievements: Detection of extra-Galactic n’s. More to come… Nobel prizes: • 2002 Davis (Cl) & Koshiba (Kamiokande) “for pioneering contributions to … detection of cosmic n’s”; • 2015 Mc. Donald (SNO) and Kajita (Super-K) “for the discovery of n oscillations, which shows that n’s have mass”.

UHE: Do we learn from (an)isotropy? Biased (rsource~map rgal for rgal>~rrgal )) CR intensity (rsource gal Galaxy density integrated to 75 Mpc [Kashti & EW 08] [EW, Fisher & Piran 97] • Anisotropy @ 98% CL; Consistent with LSS [Kotera & Lemoine 08; Abraham et al. 08… Oikonomou et al. 13] • TA 3(? )s 20 -degree “hotspot”? [Abbasi et al. 14] • Anisotropy of Z at 1019. 7 e. V implies Stronger aniso. signal due to p at (10 19. 7/Z) e. V, since acceleration & propagation of p(E/Z)= Z(E). Not observed No high Z at 1019. 7 e. V [Lemoine & EW 09]

Ice. Cube’s detection: XG CR pion production (a) UHE CR sources reside in (<1017 e. V) “Calorimeters”: Starbursts. Implications: G-XG transition @ 1019 e. V; The (G) >106. 5 e. V flux is suppressed due to propagation. or (b) Q>>QUHE sources (unknown) with tgp(pp)<<1 (ad hoc, fine tuning) & Coincidence over a wide energy range: - AGN jets in Galaxy clusters, d. Q/dlog e~1047 erg/Mpc 3 yr, tpp~10 -2 [Murase, Inoue & Nagataki 2008] - BL Lacs [“obtained through a fine-tuning with the data”, Tavecchio & Ghisellini 2015] - Low L GRBs. . .