IceCube: Neutrino Messages from GRBsinoue/GRB... · Alexander Kappes, GRB’10, Kyoto, 23. April 2010 Waxman-Bahcall spectrum Individual spectra Prompt phase: stacked searches •

Alexander KappesUniv. Erlangen / Univ. Wisconsin-MadisonDeciphering the Ancient Universe with GRBs19. – 23. April 2010, Kyoto (Japan)

IceCube: Neutrino Messages from GRBs

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Outline

• Neutrino detection & the IceCube observatory

• Current status of GRB searches with IceCube- Prompt neutrinos- Precursor neutrinos- Model independent searches

• Future perspectives with IceCube- Observational program- Optical follow-up

2

Principle of neutrino detection

muon

νμ nuclearreaction

cascade

time & position of hits

µ (~ ν) trajectory energy

PMT amplitudes

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Background: atmospheric muonsand neutrinos

4

p

atmosphere

cosmicrays

μνμ

νμcosmic

p

μνμ

• Flux from above dominated by atmospheric muons• Neutrino telescopes mainly sensitive to neutrinos from below

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Sky visibility in neutrinos

5

Horizon

above

below

IceCube at the South Pole

South Pole

IceCube surface area

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

The IceCube observatory

7

• IceTopAir shower detector

• InIce86 strings (5160 PMTs)Instrumented volume: 1 km3

Current status: 79 strings deployed-1450 m

-2450 m

Alexander Kappes, GRB’10, Kyoto, 23. April 2010 8

Current Status ofGRB Searches with IceCube

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Neutrinos from GRBs

9

Fireball model

Precursor

~-100 s T0 ~100 s > 1000 s

TeV neutrinosPeV neutrinos

EeV neutrinos

Prompt

Smoking gun evidence for hadronic acceleration → sources of UHECR

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Detection channels

Muons:• Good angular resolution

(IceCube <1° for E > 1 TeV)• Rather poor energy resolution (factor ~3)

Cascades:• Sensitive to all flavors• Better energy resolution• Reduced directional information

10

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

• GCN-satellite triggered searches

very low background → 1 event can be significant !

• Untriggered “rolling window” searches

Analysis methods

11

On-time (blind) Off-timeOff-time

T0prompt

precursor (~100 s)

wide window (several hours)

background

time1 evt2 evt

1 evt

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Prompt phase: individual GRBs

• Individual analysis of bright GRBs worthwhile• Example “naked-eye” GRB: Expected 0.1 events (9 strings)

• Expect O(1) event from bright GRBs with 86 strings

12

Γ = 300

90% CL upper limit νμ

GRB 080319BAbassi et al., ApJ 701 (2009)

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

• Individual modeling of bursts using satellite data(fireball model á la Guetta et al.)

• IceCube 40-strings: 117 GCN bursts (northern hemisphere; mainly Swift + Fermi)

• Sum expected events = 2.8; no signal found

Prompt phase: stacked searches

13

preliminary

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Waxman-Bahcall spectrum

Individual spectra

Prompt phase: stacked searches

• IceCube starts to constrain fireball model parameters

14

90% CL upper limits νμ for 117 bursts

AMANDA final(using 416 bursts)Achterberg et al., ApJ 674 (2008)

IceCube 40-strings(using 117 bursts)preliminary

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Precursor phase

• Jets with low Γ still inside progenitor star

→ TeV neutrinos

• Possibly large fraction of “choked” bursts

→ only detectable with “rolling window”

15

90% CL upper limits νμ

Rolling windowAMANDA, cascadesAchterberg et al., ApJ 664 (2007)

Triggered IceCube, 22-stringsAbbasi et al., ApJ 710 (2010)

all SNe havechoked jets

Razzaque et al., PRD 68 (2003)(H progenitors)

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

SN 2008d: neutrinos from core-collapse supernovae

16

90% CL upper limits νμ (IceCube 22-strings)

Distance: 27 Mpc• First direct observation of SN shock breakout

• X-ray flash yields precise SN time

• “Slow-jet” model(Razzaque, Meszaros, Waxman, Ando, Beacom)

• ~0.1 evts expected in IceCube 22-stringsAndo & Beacom, PRL 95 (2005):- jet points to Earth- Γb=3, Ej=3×1051

• No signal found

preliminary

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Model independent

• Model-independent approaches important→ choice of time window→ energy spectrum

• Simple approach: fixed (wide) time window

- IceCube 22 strings (41 GRBs): -1 to +3 h around GRB; No signal found

→ Average νμ upper limit (90% CL) per burst for E-2 flux: 6.6×10−5 erg cm−2 (3 TeV–2.8 PeV)

17

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

0 1 2 3 4 5 6 7 8 9

10 11 12

10 s 100 s 1000 s 10000 s0.0 ! 100

5.0 ! 10-4

1.0 ! 10-3

1.5 ! 10-3

2.0 ! 10-3

2.5 ! 10-3

3.0 ! 10-3

Muo

n N

eutr

ino

Eve

nts

Per-

Bur

st N

orm

aliz

atio

n (G

eV

cm-2

)

t (s)

Icecube 40 E-2 Muon Neutrino Flux Limits

90% Upper Limit90% Sensitivity

Approach for “arbitrary” time scales:• Start with search in small window and

increase it consecutively

• Trial factor important

• IceCube 40-strings: No signal found

Model independent

18

Sensitivity νμ (90%CL; IceCube 40-strings)

per

-bur

st n

orm

aliz

atio

n (G

eV c

m-2

)

GRB Trigger Time Difference

Weig

hte

d E

ntr

ies / b

in

-40 -20 0 20 40 600.000

0.005

0.010

0.015

emission window (s)

preliminary

Alexander Kappes, GRB’10, Kyoto, 23. April 2010 19

Future Perspectives with IceCube

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Observational program

20

Detector sensitivity still increasing significantly during next (analysis) years; operation for at least for 10 years

• Triggered searches- Stacked analysis (model dependent + independent)- Individual analyses of exceptional bursts- Satellite “coverage”:

• Present: Swift 2010 + 4 years, Fermi 2013 (+ 5 years)• Future: SVOM (planned 2012 – ?), UFFO (planned 2015 – ?),

EXIST (2017?) . . .

• Rolling-window searches important !

• All-flavor searches (cascades) underway

• Optical follow-up

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

• IceCube coincidence triggers optical follow-up- angular window 3.5°- time window 100 s

• Delay neutrino detection → start of optical observations: < 5 min

Optical follow-up

SN/GRB

Institute in the North Optical telescopes

IridiumIceCube

Alexander Kappes, GRB’10, Kyoto, 23. April 2010 22

Observational program

Kahn et al., 2006

t (days after burst)1E-4 0.01 1 100

Strizinger et al. (2003)m

agni

tud

e

t (days after burst)20 40 600

• Prompt observation (first night):Search for fast decreasing GRB afterglow- 10 short (5 s obs. time)- 10 medium (20 s obs. time) - 20 long (60 s obs. time)

• Follow-up observations (14 following nights): Slowly rising supernova light-curve- 8 long (60 s obs. time) per night

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

• Fully robotic• 24 hour (almost) all sky coverage• Large field of view (1.85˚× 1.85˚)

ROTSE telescope network

H.E.S.S., Namibia

McDonald, Texas TUG, Turkey

SSO, Australia

Alexander Kappes, GRB’10, Kyoto, 23. April 2010 24

Image processing

– =„New“ „Reference“ Subtraction

• Automatic candidate selection• Test of algorithms with simulated

SN light-curve(SN light-curve model by P. Nugent (SN1999ex))

• System successfully running since end of 2008

• Data analysis underway

Simulated SN light-curve

extr

acte

d -

mag

.

TUG, TurkeyMcDonald, Texas

Limiting mag.Measured mag.

time [days]T+0 T+10 T+20 T+30

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

Summary

• With IceCube, the first km3-scale neutrino telescope is nearing completion

• GRBs highly interesting targets for neutrino telescope

• Analyses cover wide range of scenarios;already starting to constrain models

• Optical follow-up program extends IceCube’s physics potential significantly

25

Alexander Kappes, GRB’10, Kyoto, 23. April 2010

The IceCube collaboration

Alexander Kappes PANIC'08, Eilat 16

• 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 • Universität Bonn

• 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