neutrino “astronomy” · • introduction • we built a km3 neutrino detector 3 challenges: •...

francis halzen university of wisconsin

http://icecube.wisc.edu

neutrino “astronomy”

• introduction

• we built a km3 neutrino detector 3 challenges:

• drilling

• optics of ice

• atmospheric muons

• search for the sources of the Galactic cosmic rays

• search for the extragalactic cosmic rays

• gamma ray bursts

• active galaxies

dark matter

IceCube.wisc.edu

TeV sources

cosmic rays

Rad

io

CM

B

Vis

ible

GeV

g-r

ay

s

energy (eV)

flu

x

n

particle flux

In the Universe

Pacini 1910

1911

neutrino sky

requires a km2

neutrino telescope

cosmic rays interact with the

microwave background

0g pandnp

TeV102E 6

cosmic rays disappear, neutrinos appear

{e e}

~1 event per cubed kilometer per year

M. Markov

1960

B. Pontecorvo

M.Markov :

we propose to install detectors

deep in a lake or in the sea and

to determine the direction of

charged particles with the help

of Cherenkov radiation.

• lattice of photomultipliers

• shielded and optically

transparent medium

n

n

n

n

RnP

energy measurement ( > 1 TeV )

e+e-

g pair-creation

bremsstrahlung

photo-nuclear

convert the amount of light emitted

to measurement of the muon

energy (number of optical modules,

number of photons, dE/dx, …)

muon track

main board

LED flasher board

HV board

architecture of independent DOMs

10 inch pmt

improving angular and energy resolution

why did it take so long ?

IceCube / Deep Core

Digital Optical Module (DOM)

• 5320 optical modules on 86 strings ( + IceTop)

• detects ~220 neutrinos and 3x108 muons per day

• threshold 10 GeV

• angular resolution

< 1 degree

completed December 18, 2010

IC-1

04-05 Season

IC-9

05-06 Season

IC-22

06-07 Season

IC-40

07-08 Season

IC-59

08-09 Season

IC-79

09-10 Season

IC-86

10-11 Season

each DOM is

independent:

continuously

sends time-

stamped

wave forms

27

89 TeV

• introduction

•we built a km3 neutrino detector 3 challenges:

• drilling

• optics of ice





• active galaxies

dark matter

IceCube.wisc.edu

… you looked at 10msec of data !

muons detected per year:

• atmospheric* ~ 1011

• atmospheric** n ~ 105

• cosmic n ~ 10

* 3000 per second ** 1 every 6 minutes

moon shadow

> 16

~ 0.1 deg

… on to IceCube science

we measure the flux of atmospheric muons and

neutrinos at higher energies and with better

statistics than previous experiments. Any deviations

from what is expected is new neutrino physics or

new astrophysics. We just look for surprises.

cosmic

neutrinos:

energy:

>> 100 TeV

atmospheric neutrino spectrum to >100 TeV

zenith angle

two analyses

matter effect

of eV sterile n’s ?

3

3+1

zenith angle distribution

not even preliminary

59 strings

… on to IceCube science

we measure the flux of atmospheric muons and

neutrinos at higher energies and with better

statistics than previous experiments. Any deviations

from what is expected is new neutrino physics or

new astrophysics. We just look for surprises.

• introduction


• drilling

• optics of ice


• search for the sources of the cosmic rays



• active galaxies

dark matter

IceCube.wisc.edu

cassiopeia A supernova remnant in X-rays

gravitational energy

released is trans-

formed into

acceleration

E-2 spectrum

acceleration when

particles cross

high B-fields

and if the star collapses to a black hole …

collapse of massive

star produces a

gamma ray

burst

shocks produced

in the outflow of

the spinning

black hole:

electrons (and

protons ?)

spinning black hole

and if the star collapses to a black hole …

happens in seconds not thousands of years

beamed not spherical

simulation not image

Hillas formula :

qBRvE

RvqB

ERgyro

)(

• dimensional analysis, difficult to satisfy

• accelerator must contain the particles

Cosmic Rays & SNRs

supernova remnants:

1050 ergs every 30 years

~10-12 erg/cm3

for steady state of CR

with lifetime ~106 years

SNRs provide the environment and energy

to explain the galactic cosmic rays!

observed energy

density of galactic CR:

~ 10-12 erg/cm3

galactic

Cosmic Rays & GRBs

Extragalactic

Gamma-Ray Bursts:

1052 ergs x 300/Gpc3

x 1010 yr

~ 10-19 erg / cm3

GRBs provide environment and energy

to explain the extragalactic cosmic rays!

observed energy

density of

extragalactic CR:

~ 10-19 erg / cm3

directions of ~ 600 neutrinos

early

astronomy

AMANDA

2000

IceCube 40 strings

operated 375.5 days northern sky: 14139 neutrinos

southern sky: 23151 muons

search for

• clustering

• high energy (>> 100 TeV)

• nothing seen

• nothing expected

next?

neutrinos

•about to unblind one year of data for 79 strings

•one year of data with completed detector on tape

• introduction


• drilling

• optics of ice





• active galaxies

dark matter

IceCube.wisc.edu

Galactic

cosmic rays :

must produce

pionic g-rays

in interactions

with hydrogen

in Galactic plane

(1 proton cm-3)

cr + p pions

0 gg

trace cosmic

rays

Galactic extragalactic

produce 100 TeV

gamma rays

Galactic plane in 10 TeV gamma rays : supernova remnants in star forming regions

Southern

Hemisphere

Sky

Sta

ndard

Devia

tions

30°

210°

90° 65°

milagro

neutrinos

from

supernova

remnants :

molecular

clouds as

beam

dumps

n + n -

+

+ -

e+ ne

e+ e-

e+

g

0

g

g e-

e+ g

n

neutral pions

are observed as

gamma rays

charged pions

are observed as

neutrinos

nn = g g

Cygnus region : Milagro

translation of

TeV gamma rays

into

TeV neutrinos :

3 ± 1 n per year in IceCube per source

5 in 5 years of IceCube …

IceCube image of our Galaxy > 10 TeV

first surprise

cosmic rays

in IceCube 10 TeV

to several

100 TeV

10 TeV

2 KHz

3 deg resolution

• we map the highest

energy Galactic

cosmic rays, but…

• their gyroradius is

< 1 pc in microgauss

magnetic field

• closest sources

> 100 pc

should not point! that’s why we

detect neutrinos!

32 billion cosmic ray muons/ 59 strings

Smoothing scan results

Abbasi et al., ApJ, 740, 16, 2011 arxiv/1105.2326

Skymap energy dependence summary

40 TeV

40 TeV


100 TeV


126 TeV


200 TeV


316 TeV


400 TeV


630 TeV


1 PeV


5 PeV


10 PeV

Wolfendale – Erlykin

Single Source Model

-- a recent, nearby Supernova IIa --

single source: more IceTop data required

• introduction


• drilling

• optics of ice





• active galaxies

dark matter

IceCube.wisc.edu

… often wrong, but never in doubt …

Galactic:

supernova

remnants?

extragalactic:

gamma ray

bursts?

active

galaxies?

solar cosmic

rays

collapse of massive

star produces a

gamma ray

burst

neutrinos are

produced in the

interactions of

fireball protons

(cosmic rays)

with synchrotron

photons

spinning black hole

decays to neutrino

decays to cosmic ray

GRB: one neutrino per cosmic ray observed

Search for GRB in coincidence with FERMI and SWIFT alerts

collide cosmic rays of

GRB

origin with fireball and

microwave photons

0g pandnp

cosmic rays from n-decay

GRB origin of cosmic

rays challenged

0 gamma rays after

cascading in the

microwave background + neutrinos

active galaxy

particle flows near

supermassive

black hole

cosmic rays interact with the

microwave background

0g pandnp

TeV102E 6

cosmic rays disappear, neutrinos appear

{e e}

~1 GZK event per cubed kilometer per year

• introduction


• drilling

• optics of ice





• active galaxies

dark matter

IceCube.wisc.edu

c

WIMP Capture and Annihilation

DETECTOR

n

n

c + c W + W n + n

b + b n + n

Galactic Center

in

neutrinos and

muons

~20σ

without

oscillations

with

oscillations

3+1 neutrinos?

IceCube science

conclusions

• Hess 1912…. and still no conclusion

• the instrumentation is in place …

• … supernova remnants,GZK neutrinos

and GRB are in close range !

• unblinding 59, 79 data by Neutrino 2012

Overflow slides

CLatmsstart

samplingmwithevents

%953:

sec7.1106

supernova

quantized space: matter where the geometry is activated

cm3310E1~

n

quantized space: matter where the geometry is activated

Lorentz violation from Planck scale

violation of Lorentz invariance may be a tool to study

Planck scale physics

interaction with Planck mass particles distort

spacetime

Planck scale vacuum fluctuations probed by

high energy neutrinos

modification to dispersion relation leads to an energy

dependent speed of light.

...)(2222 n

PlanckM

EEmpE

violation of Lorentz invariance because of Planck scale

physics can be detected through time delays of high

energy neutrinos relative to low energy photons

from a source at a distance d; for instance a GRB.

n

PlanckM

E

c

dnt

n

2

1

sensitivity to Planck scale !

Lorentz violation: E vs t





n

PlanckM

E

c

dnt

n

2

1

Lorentz violation: E vs t





PlanckMt

E

c

dscaleenergy

tests

• equivalence

principle

and

• Lorentz

invariance

…general

relativity

will not last

200 years…

M. Turner

IceCube

radiation and dust

black hole

p + 0

~ cosmic ray + gamma

NEUTRINO BEAMS: HEAVEN & EARTH Neutrino Beams: Heaven & Earth

p + g n + +

~ cosmic ray + neutrino

n and g beams : heaven and earth

1~1.5 events/yr

59 strings

• crash program in calibration and systematics

• check against 59 strings data

The Italian Navy Cacciatorpediniere “Fulmine” used

by Pacini in 1910-1911

Moon shadow observed in muons – IceCube points in the right direction!

Center of moon is spot on

to a precision of <0.1 degrees.

Statistical significance with

IC 59: > 10 sigma

145

One benchmark analysis as performance measure: Point source searches, E^-2 flux limits and sensitivities

original IC80

est. in 2004

paper

Example: Energy resolution Muon energy: rms of log(E) ~

0.15

Muon neutrino: 0.3 (inevitable

physics fluctuations from

neutrino energy to muon

energy at detector)

Electron neutrino cascades:

rms of log(E): ~ 0.175

sigma of peak: 0.07

Muon energy resolution

neutrino “astronomy” · • introduction • we built a km3 neutrino detector 3 challenges: •...

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