news from the south pole: recent results from the icecube and amanda neutrino telescopes

News from the South Pole: Recent Results from the IceCube and

AMANDA Neutrino Telescopes

Alexander KappesUW-Madison

PANIC ‘08November 2008, Eilat (Israel)

Outline

• High-energy cosmic neutrino sources

• The IceCube and AMANDA neutrino telescopes

• Physics topics (recent results)– Moon shadow– Steady point-like sources– Gamma ray bursts– Dark Matter (WIMPs) Talk by Catherine De Clercq➞– Exotic physics Talk by John Kelley➞

Alexander Kappes PANIC'08, Eilat 2


Target:•photon field•molecular cloud•interstellar medium

Cosmic rayaccelerator

p + p() → ± + X + e + e +

cosmic ray + neutrinos

p + p() → 0 + X

cosmic ray + photons

Supernova remnants(Cas A)

Gamma-ray bursts(GRB 080319B, Swift)

?

Principle of neutrino detection


nuclearreaction

muon

• infrequently, a cosmic neutrino crashes into an atom in the ice and produces a nuclear reaction

• muon travels kilometers in the ice

• blue (Cherenkov) light produced • optical sensors capture (and map) the light

IceTop

InIce

• Air shower detector• 160 ice-tanks in

surface array• Threshold ~ 300 TeV

• 80 Strings each with• 60 Optical Modules• 17 m between Modules• 125 m between Strings

2004-2005 : 1 String

2005-2006: 8 Strings

AMANDA

(1995-2000)

19 Strings

677 Modules

Currently deployed:40 Strings80 IceTop tanks3 more seasons planned

2006-2007:13 Strings

2007-2008:18 Strings

1450m

2450m

The IceCube and AMANDA neutrino telescopes

Alexander Kappes 5PANIC'08, Eilat

Backgrounds: Atmospheric muons & neutrinos


Backgrounds: - Downgoing μ - Atmospheric ν

Data-MC comparison

Down-goingatm. muons

Up-going-induced muons

• Significantly higher sensitivity for up-going

• High-purity (atmospheric) up-going neutrino sample after cuts

Cosmic neutrinos typicallyhave harder spectra (E-2)

Pointing accuracy: the Moon shadow in IceCube 40-strings

• Moon shadow observed in first 3 months of IC40 data

• Validates pointing capabilities:

Angular resolution:– IceCube 22 < 1.5°– IceCube 80 < 1°


Preliminarytrue moon mean from

fake moons

difference

2000-2006 AMANDA point source search

• Unbinned likelihood method using energy information• Final 7 year AMANDA (3.8 yr livetime) analysis• 95% of RA-randomized skymaps have maximum significance > 3.38 σ

→ Not significant


Significance

Max Significanceδ=54o, α=11.4h 3.38σ

2000-2006 AMANDA point source search

• Unbinned likelihood method using energy information• Final 7 year AMANDA (3.8 yr livetime) analysis• 95% of RA-randomized skymaps have maximum significance > 3.38 σ

→ Not significant


Significance

Max Significanceδ=54o, α=11.4h 3.38σ

3yr max significance: 3.73σ 1.5σ

5yr max significance: 3.74σ 2.8σ

Search for point sources with IceCube 22-strings

• Unbinned likelihood method using energy information• Hottest spot found at r.a. 153º , dec. 11º• pre-trial p-value: 7×10-7 (4.8 sigma)• Accounting for all trials, p-value for analysis is 1.34% (2.2 sigma).• At this significance level, consistent with fluctuation of background.

Alexander Kappes 10PANIC'08, Eilat

preliminary

Current neutrino flux limits / sensitivities


IceCube 22

AMANDA 3.8 years

IceCube 80

Analysis of “naked eye” GRB 080319B

March 19, 06:12:49 UTC (duration ~70 s) Position: RA = 217.9º, Dec = +36.3º

Brightest (optical) GRB ever observed: z = 0.94 (DA = 1.6 Gpc, light travel time 7.5 Gyr)

Expect ~0.1 events in IceCube 9-strings(Fireball model, = 300)


Pi-of-the-Sky (optical)

Analysis of “naked eye” GRB 080319B

March 19, 06:12:49 UTC (duration ~70 s) Position: RA = 217.9º, Dec = +36.3º

Brightest (optical) GRB ever observed: z = 0.94 (DA = 1.6 Gpc, light travel time 7.5 Gyr)

Expect ~0.1 events in IceCube 9-strings(Fireball model, = 300)

Unbinned likelihood methodyields 0 signal events

Expect O(1) event in IceCube 80from similar burst!


Pi-of-the-Sky (optical)

Gamma-ray bursts with IceCube 22-strings

• Currently analyzing data from41 bursts (Swift, AGILE + others)

• Individual modeling of burstsaccording to GRB fireball model

• Expected events:– average Waxman-Bahcall ~0.7– individual GRB spectra ~0.5

• Outlook:IceCube 80 will be able to seeWB GRB flux within few years


Discovery potential for average WB bursts

~30% chance

preliminary

Conclusions and Outlook

• IceCube halfway completed (40 strings), completion planned for 2011

• Verification of pointing accuracy via observation of Moon shadow

• Search for point-like sources over the whole sky– Final AMANDA 7 year (3.8 years livetime) analysis– IceCube 22-string analysis➞ no significant access above background observed

• Search for neutrinos from gamma-ray bursts– Individual analysis of “naked eye” GRB 080319B

no signal events found➞– Analysis results for 41 bursts with IceCube 22-strings coming soon

• With the nearing completion of the first km3-scale detector, IceCube,neutrino astronomy enters into a new era


Exciting times lie ahead !

The IceCube collaboration

The IceCube collaboration


• Univ Alabama, Tuscaloosa • Univ Alaska, Anchorage • UC Berkeley• UC Irvine • Clark-Atlanta University• U Delaware / Bartol Research Inst• Georgia Tech• University of Kansas • Lawrence Berkeley National Lab• University of Maryland• The Ohio State University• Pennsylvania State University• University of Wisconsin-Madison• University of Wisconsin-RiverFalls• Southern University, Baton Rouge

• Universität Mainz • Humboldt Univ., Berlin • DESY, Zeuthen• Universität Dortmund• Universität Wuppertal• MPI Heidelberg • RWTH Aachen

• Uppsala University• Stockholm University

Chiba University

• Universite Libre de Bruxelles• Vrije Universiteit Brussel• Université de Mons-Hainaut• Universiteit Gent • EPFL, Lausanne

Univ. of Canterbury, Christchurch

University of Oxford

University Utrecht

32 Institutions, ~250 members

Backup


Effective muon neutrino area


Separation of atmospheric and cosmic neutrinos


• Atmospheric neutrinos irreducible background(~60,000 per year in IceCube with 80 strings)

• Cosmic neutrinos typically have harder spectra (E-2)(detected events peak at higher energies)

A Priori Source List for IC22 Obj. Name ra(deg) dec(deg) p-value (pre-trial) ------------- ------- ------ -------- MGRO_J2019+37 (304.830 , 36.830) : 0.251 MGRO_J1908+06 (287.270 , 6.280) : ----- Cyg_OB2 (308.083 , 41.510) : ----- SS_433 (287.957 , 4.983) : 0.317 Cyg_X-1 (299.591 , 35.202) : ----- LS_I_+61_303 ( 40.132 , 61.229) : ----- GRS_1915+105 (288.798 , 10.946) : ----- XTE_J1118+480 (169.545 , 48.037) : 0.082 GRO_J0422+32 ( 65.428 , 32.907) : ----- Geminga ( 98.476 , 17.770) : ----- Crab_Nebula ( 83.633 , 22.014) : ----- Cas_A (350.850 , 58.815) : ----- Mrk_421 (166.114 , 38.209) : ----- Mrk_501 (253.468 , 39.760) : ----- 1ES_1959+650 (299.999 , 65.149) : 0.071 1ES_2344+514 (356.770 , 51.705) : ----- H_1426+428 (217.136 , 42.672) : ----- 1ES_0229+200 ( 38.202 , 20.287) : ----- BL_Lac (330.680 , 42.278) : 0.368 S5_0716+71 (110.473 , 71.343) : 0.309 3C66A ( 35.665 , 43.035) : 0.313 3C_454.3 (343.491 , 16.148) : ----- 4C_38.41 (248.815 , 38.135) : ----- PKS_0528+134 ( 82.735 , 13.532) : ----- 3C_273 (187.278 , 2.052) : 0.369 M87 (187.706 , 12.391) : ----- NGC_1275 ( 49.951 , 41.512) : 0.213 Cyg_A (299.868 , 40.734) : -----

(only excesses reported, otherwise given as “---”)

Lowest p-value (0.07) is for 1ES 1959+650.

Not significant after trial factor of 28 sources in list.

All Flavor GRB Limits from AMANDA IIAll Flavor GRB Limits from AMANDA II

Limits from triggered searches assume ~700 bursts per year

~420 GBs investigated

AMANDA starts to excludeflux models!

Cascade search in IceCubemuch more competitive(factor 70 in instrumented vol.)

Eff. volume (cascades) grows faster than eff. area (muon)!

Muonsearches(only trig)

Cascadesearches

(trig + roll)only

rolling

news from the south pole: recent results from the icecube and amanda neutrino telescopes

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