High Energy Neutrino Astronomy

Gisela AntonLAUNCH 09Heidelberg, November 10th, 2009

High Energy Neutrino Astronomy

Alexander Kappes, DPG-Frühjahrstagung, München, 12.03.2009 2

Content

• Introduction to high energy neutrino astronomy

• Neutrino-Telescopes: IceCube and ANTARES

• Selected results

• Future perspectives of IceCube und KM3NeT

Gisela Anton, LAUNCH 09, Heidelberg, November 10th, 2009


Messengers of the high energy universe


p

p

e

Cosmic ray spectrum


The high energy universe

Gamma-ray Burst(GRB 080319B, X-Ray, SWIFT)

Active Galactic Nuclei(artists view)

Supernova Remnant(SN1006, optiical, radio, X-ray)

Microquasar(artists view)



Acceleration of particles

• Shock front (Fermi-acceleration)

• Objects with strong magnetic fields (pulsars, magnetars)

Beam dump (secondary particles)

• Interaction of high energy particles with photons or matter

- Protons: pion production and decay

- Electrons: inverse Compton-Scattering of Photons

e + γ(low energy) → e + γ (TeV)

Production mechanisms

p + p(γ) → π± + X μ + νμ

e + νμ + νe

p + p(γ) → π0 + X γ + γ (TeV)



• Photon ↔ neutrino connection:

• Observed from RX J1713.7–3946:

- γ-rays up to several 10 TeV

→ particle acceleration up to 100 TeV and above

• Calculated neutrino fluxes:

Estimated neutrino fluxes (SNR)

RX J1713.7–3946

p + p → π± + X μ + νμ

e + νμ + νe

p + p → π0 + X γ + γ

For strong sources:

10-12–10-11 TeV-1 cm-2 s-1 @ 1 TeV

AK, Hinton, Stegmann, Aharonian, ApJ (2006)Halzen, AK, O’Murchadha, PRD (2008)Kistler, Beacom, PRD (2006). . .

AK, Hinton, Stegmann, Aharonian, ApJ (2006)



Neutrinos as cosmic messengers

• Neutrinos point back to sources

• Neutrinos travel cosmological distances

• Neutrinos escape dense sources

• Neutrinos are related to hadron acceleration

• Neutrinos complement high energy proton and gamma observation



Detection of Neutrinos

muon

νμnuclearreaction

cascade



Background: atmospheric muonsand neutrinos

p

atmosphere

cosmicrays

μνμ

νμ

cosmic

background

p

μνμ

• Flux from above dominated by atmospheric muons

• Neutrino telescopes mainly sensitive to neutrinos from below



Sky visibility in neutrinos

Horizon

above

below



Neutrino Telescopes:

Baikal, IceCube and ANTARES



• NT200

• 8 strings (192 optical modules)

• Instrumented volume 1×10-4 km3

• Running since 1998

• NT200+

• NT200 + 3 outer strings(36 optical modules)

• Instrumented volume 0.004 km3

• Running since 2005

Baikal NT200+

Single storeySingle storey



Sky coverage

Visibility ANTARES (Mediterranean Sea) > 75% 2 25% – 75% < 25%

TeV γ-Sources galactic extragalactic

Visibility IceCube (Southpole) 100% 0%



IceCube at the Southpole

Southpole

IceCube



I



ANTARES in the Mediterranean

Main cable (45km)

Shore station



• 12 Lines (885 PMTs)

• Completion May 2008

• Instrumented volume: ~0.01 km3

ANTARES

2100 m

2475 m



• Lines moving in the sea current

• Acoutic positioning system + tiltmeter and compasses:

x < 10 cm

• Monitoring of the positioning with laser pulses

Precision ~0.5 ns = 10 cm

Position determination for PMTs

Laser

0.5 ns

0-1-2-3-4 1 2 3 4Time measured – calculated (ns)



Optical Background

Optical background due to 40K-decay and bioluminescense

• Typical rate per PMT 60-100 kHz

• Additional short bursts and periods with higher rates

Mar.’06 Sept.’06 Mar.’07 Sep.’07 Mar.’08

Med

ian

rate

(kH

z)



Selected Results



ANTARES: Atmospheric Myons & Neutrinos

up going:ν-induced myons

ANTARES (173 days)

down going:atm. myons



• Need of calibration source for proof of detector pointing capability and resolution

• Nature offers deficit of muons from direction of the Moon

- Diameter of the Moon 0.5°

Angular resolution

- IceCube 80-String < 1°

- ANTARES < 0.5°

• First observation of the Moon shadow with IceCube 40-String data

IceCube: the shadow of the moon


A. Karle @ ICRC 2009

RA relative to moon position

Dec

rel

. m

oo

n


Search for point sources – IceCube 40 strings (6 months)

PreliminaryBackground: atm. neutrinos(6796 events)

(10981 events)Background: atm. muons

Most-significant spot:all-sky background probability: 61%

Significance



Point source sensitivities

ANTARES: 12 lines 1 year (pred. sensitivity)

Flux predictionsHalzen, AK, O’Murchadha, PRD (2008)AK, Hinton, Stegmann, Aharonian, ApJ (2006)Kistler, Beacom, PRD (2006)Costantini & Vissani, App (2005). . .

MACRO (6 years)Super-K. (4.5 years)

AMANDA (3.8 years)

IceCube: IceCube 40 Strings 330 days (sensitivity)

IceCube 80 Strings 1 yr (pred. sensitivity)

90% CL sensitivity for E-2 spectra (preliminary)



triggered Search• Sensitivity gain due to time and direction of burst measured by satellites• Low number of events per GRB expected “Burst-Stacking” ➞

Un-triggered Search• Possible large population of “choked“ GRBs; unvisible in γ-rays• Search for excess of events in time and direction

Gamma-Ray Bursts

Fireball model

Precursor

~-100 s T0 ~100 s > 1000 s

TeV neutrinosPeV neutrinos

EeV neutrinos

Prompt



Limits on neutrino fluxes from GRBs

precursor prompt

precursor: Meszaros & Waxman, PRL (2001) prompt: IceCube, AK et al., ICRC2009

• Perspectives:

• 200 – 300 GRBs per year (Fermi, SWIFT)

• IceCube will be able to detect predicted fluxes within next years

• Baikal NT200+ (155 GRBs)(Avrorin et al., arXiv:0910.4327)

• IceCube 22-Strings (41 GRBs)(Abbasi et al, arXiv:0907.2227)

• AMANDA (417 GRBs)(Achterberg et al. (2008) ApJ 674, 357)

predictions

IceCube

Baikal

IceCube

Amanda



• First proposed by M. Kowalski (Kowalski and Mohr (2007), App 27, 533)

• IceCube: cooperation with ROTSE (4 telescopes)

• Antares: cooperation with TAROT (2 telescopes)

Optical Follow-Up

SN/GRB

robotic optical telescopes

neutrinotelescope

send alert



• Neutralino (χ) good WIMP candidate• Gravitational capture in the Sun + self annihilation

• Neutrino rate only depends on scattering cross section

(equilibrium between capture and annihilation)

Dark Matter Searches (WIMPs)

χ

ν

-ν



`

IceCube 86 with Deep CoreSensitivity 1 yr (prel., hard)

WIMP searches

Direct detection experiments (CDMS, COUPP, KIMS)

Super-Kamiokande (2004)

AMANDA 7 years soft hard

IceCube 22-strings limits(PRL 102, 201302 (2009)) soft hard

MSSM models}


Alexander Kappes, DPG-Frühjahrstagung, München, 12.03.2009

Expected Neutrino Events from Dark Matter Annihilation in ANTARES



Further Physics

Point Sources:

• Variable Sources

- Extragalactic -source candidates are non persistent

- Time search window given for instance by γ-ray signals reduction of background

• Target of opportunity: 2 neutrinos within t from same direction send alert to optical telescope for follow up

Other Topics:

• Supernovae (MeV neutrinos)

• Neutrino oszillation (atmospheric neutrinos 10 - 100 GeV)

• Exotic physics (Lorentz symmetry violation, monopoles, . . .)



Perspectives with

IceCube und KM3NeT



• IceCube: compared to AMANDA (7 years)factor 25 increased sensitivity

- larger detector + data quality

- accumulated data

- improved analysis methods

• IceCube is in the region of realistic discovery potential, but

- flux estimates indicate that IceCube is at the edge of the interesting region

- IceCube covers only have of the sky

Future of Neutrino-Astronomy Spiering, HGF review, 2009



• km3-scale neutrino telescope in the Mediterranean

( and infrastructure for marine and Earth science)

• Common effort of ANTARES, NEMO and NESTOR pilot projects

+ Institutes from marine science and oceanographic technologies

• On the Roadmap of the European Strategy Forum for Research Infrastructures (ESFRI)

• EU financed Design Study (2006-2009)

• EU financed Preparatory Phase (2008-2012)

KM3NeT

Artists view



• Semi-rigid system of horizontal elements (storeys):

• 20 storeys

• Each storey supports 6 OMs in groups of 2

• Storeys interlinked by tensioning ropes, subsequent storeys orthogonal to each other

• Power and data cables separated from ropes

Flexible tower with horizontal bars

6 m

40 m



OM with many small PMTs

• 31 3-inch PMTs in 17-inch glass sphere (cathode area ~3x10” PMTs)

- 19 in lower, 12 in upper hemisphere

- Suspended by compressible foam core

• 31 PMT bases (D) (total ~140 mW)

• Front-end electronics (B,C)

• Al cooling shield and stem (A)

• Single penetrator

• 2mm optical gel (ANTARES-type)

A

B

CC

D

PMT



KM3NeT Point Source Sensitivity (3 years)Aharens et al. Astr. Phys. (2004) – binned method

Average value of sensitivity fromR. Abbasi et al. Astro-ph (2009)

R. Abbasi et al. Astro-ph (2009) scaled – unbinned method

Observed Galactic TeV- sources (SNR, unidentified, microquasars)

Aharonian et al. Rep. Prog. Phys. (2008), Abdo et al., ApJ 658 L33-L36 (2007)

KM3NeT(binned/unb.)

IceCube

Typical fluxes

Estimated costs: ~100 MEuro (+10% man power)

Note: Double sensitivity for about double price . . .



• Next steps: Prototyping and design decisions

• organized in Preparatory Phase framework

• final decisions require site selection

• expected to be achieved in ~18 months

• Timeline:

KM3NeT Timeline

Feb 2

006

Mar

200

8

Oct 2

009

Mar

201

2

Construction phase

Data taking phase

TDRCDR

Design Study

Preparatory Phase

2011

Designdecision

2013

2015

2017



Summary

• High energy neutrinos deliver complementary information to gamma photons and protons

• ANTARES completed , IceCube 70% installed, KM3NeT in design phase

• No cosmological high energy neutrinos observed yet

• IceCube will enter the region with discovery potential

• KM3NeT will exceed IceCube



Thank you for your attentionmuon

νμnuclearreaction

cascade


Documents

High Energy Neutrino Astronomy