icecube a new window on the universe muons & neutrinos neutrino astronomy icecube science status...

IceCubea new window on the Universe

• Muons & neutrinos

• Neutrino astronomy

• IceCube science

• Status & plans

Tom Gaisser for the IceCube Collaboration Arequipa, Peru, Sept. 1, 2008

• 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• Pennsylvania State University• University of Wisconsin-Madison• University of Wisconsin-RiverFalls• Southern University, Baton Rouge

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

• Uppsala University• Stockholm University

• Uppsala University• Stockholm University

Chiba University

Chiba University

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

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

Univ. of Canterbury, Christchurch Univ. of Canterbury, Christchurch

• University of Oxford• University of Oxford

University Utrecht University Utrecht

The IceCube Collaboration

The neutrino landscape

Prompt

e

Solar

Lines show atmosphericneutrinos + antineutrinos

Slope = 3.7

RPQM for prompt from charmBugaev et al., PRD58 (1998) 054001Slope = 2.7

Astrophysical neutrinos (WB “bound” / 2 for osc)

Expected flux of relic supernova neutrinos

Cosmogenic neutrinos

Atmospheric neutrinos

• Produced by cosmic-ray interactions– Last component of secondary cosmic

radiation to be measured– Close genetic relation with muons

• p + A ± (K±) + other hadrons

• ± (K±) ± + ()

• ± e± + () + e (e)

– Above ~2 GeV muons reach the ground before decaying

e

e

p

High-energy atmospheric neutrinos

Primary cosmic-ray spectrum (nucleons)

Nucleons produce pions

kaons

charmed hadrons

that decay to neutrinos

Kaons produce most

for 100 GeV < E < 100 TeV

Eventually “prompt ” from charm decay dominate, ….but what energy?

Neutrinos from kaons

Critical energies determine where spectrum changes, but AK / A and AC / AK determine magnitudes

New information from MINOS relevant to with E > TeV

1.27

1.37

x

x

TeV +/- with MINOS far detector

• 100 to 400 GeV at depth > TeV at production

• Increase in charge ratio shows– p K+ is important– Forward process– s-quark recombines

with leading di-quark

– Similar process for c? Increased contribution from kaons at high energy

Neutrinos from charm

• Main source of atmospheric for E > ??

• ?? > 20 TeV

• Large uncertainty!

Gelmini, Gondolo, Varieschi PRD 67, 017301 (2003)

Angular dependenceFor K < E cos() < c , conventional neutrinos ~ sec() , but “prompt” neutrinos independent of angle

Uncertain charm component most important near the vertical

Detecting neutrinos

• Rate– Convolution of:

• Neutrino flux• Absorption in Earth• Neutrino cross section• Range of muon• Size of detector

Probability to detect-induced muon:

Neutrino effective area

• Rate:

= ∫(E)Aeff(E)dE

• Earth absorption– 10-100 TeV

• cos() > -0.8• Main effect near

vertical

– Higher energy ’s absorbed at larger angles

IceCube acceptance, resolution

Atmospheric muons in telescopes

Angular-dependence of muons in SNO at 6000 m.w.e. depth Crossover of -induced at 60o !

Depths of large neutrino telescopes

Million to 1 background to signal from above. Use Earth as filter; look for neurtinos from below.

Muon signal from all directions

Downward atmospheric muons

Upward neutrino-induced muons

Patrick Berghaus et al., Cosmo-08 and ISVHECRI-08

IceCube 22: signal from below at trigger level, background / signal = 1000 / 1

Efficiency at final cut level ~ 10%

Unrelated muons from different cosmic-ray primaries in the same time window

IC22 Events

Downward cosmic-ray event (“muon bundle”) Upward candidate event

( Red hits = early; yellow/green/blue = later ) IceCube DOM locations blue, AMANDA OM locations red

Neutrino astronomy with IceCube

Accretion and jets formationAccretion and jets formationA common phenomenon on both A common phenomenon on both stellar & galactic scales:stellar & galactic scales:Matter falls onto black hole or neutron Matter falls onto black hole or neutron star driving collimated, relativistic jets star driving collimated, relativistic jets perpendicular to the diskperpendicular to the disk

AGN, other extra-galactic sources

Micro-quasars, galactic sources

Expect hard spectrum(like cosmic-ray source, E-2 )

Cutoffs ~10 – 100 TeV expected for galactic sources M. Urry, astro-ph/0312545

Limits on excess of above atmospheric background

Jim Braun, UW Madison, presented at Cosmo-08

Point source search with 7 years of AMANDA 3.8 yrs livetime 26 candidate sources

- 10 seconds

fireball protons interact with remnant

of the star

0 seconds

fireball protons and

photons interact

afterwards

afterglow protons interact with inter-

stellar medium

TeV

PeV

EeV

Image: W. Zhang & S. WoosleySee astro-ph/0308389v2

Jet breakout in GRB following collapse of massive progenitor star

Slide from Alexander Kappes

Search for neutrinos from GRB

Cascade(Trig & Roll)

Cascade(Rolling)

search

All flavor limits by AMANDAGRB models

Waxman-BahcallPRL 78 (1997) 2292

Murase-Nagataki APRD 73 (2006) 063002

Supranova,Razzaque et al.PRL 90 (2003) 241103

Choked burstsMeszaros-WaxmanPRL 87 (2001) 171102

Limits on neutrinos from GRB from AMANDA: -from cascades (e, ), Ap.J. 664 (2007) 397-from neutrino-induced muons, Ap.J (to be published)

Prospects for detecting GRB ’s with IceCube

• Advantage:– time window and direction defined by satellite observation

of the GRB– Observation of coincidences removes background

• AMANDA limits– Already disfavor some models– Sensitivity close to classic Waxman-Bahcall fireball

prediction (expected ~ 1 in 400 GRBs)• IceCube sensitivity ~20 times AMANDA

– 200 GRB / yr expected from GLAST– Expect 3 detection of Waxman-Bahcall level in 70 GRB

with full IceCube– Non-observation would indicate GRB jets are pure

Poynting flux (Blandford) rather than baryon loaded plasma (Piran, Meszaros, …)

• IceCube to send alerts to ROTSE

Shadow of the Moon in IC40

Laura Gladstone,Jim BraunCosmo-08

Related science with IceCube

• Archaeology of ice• Physics by monitoring counting rates:

– Supernova watch– Solar activity, solar flares, etc.

• Indirect search for dark matter:– WIMP annihilation in the Sun

• Neutrino physics– Oscillations at high energy?– Energy dependence of neutrino cross section

• Measure Earth density profile – Use energy and angle dependence of 10-100 TeV atmospheric

neutrinos (The Economist, November, 2007)

• High-altitude pressure, weather from muon & IceTop counting rates• High-energy cosmic rays (< 1 PeV to > 1 EeV )

13 Dec 2006 solar flare in IceTop

During transition from TICL to ICL

Cosmic-ray physics with

IceCube

• E-spectrum• Composition

– Coincident events: / e

– Knee to transition from galactic

• Calibration, partial veto for IceCube

LHC

Tevatron

DIRECT AirShowers

Extra-galactic component ?

Galactic cutoff~ 3 x 1015 eV ?

Composition with air showers

• Proton penetrates deep in atmosphere– Shower max deeper– ( mu / e ) smaller– muons start deeper

• Heavy nucleus cascade starts high– shower max higher up– ( mu / e ) larger– muons start higher

protonheavy nucleus

Depth of maximum via air Cherenkov or fluorescence

1018 eV proton

Depth of IceTop

Preliminary IceTop Spectrum

Composition from angular dependence of spectrum

Protons only Iron only 5-compnents

(lig

ht f

rom

muo

ns in

ice)

(electrons at surface)

(lig

ht f

rom

muo

ns in

ice)

(electrons at surface)

Composition from In-ice / IceTop (/e)

• Use coincident events• Reconstruct muon

bundle in-ice to obtain energy deposition by muons

• Reconstruct surface shower to get Eprimary

• Require consistency with angular distribution and /e at the surface Simulation for SPASE-AMANDA

An EeV event in IC40

125 m

High Energy Earth Science Tom GaisserTokyo, June 26, 2008 Photo: James Roth 17-12-2007

IceCube photo gallery

• 22 strings running in 2007• 18 strings deployed in 07 / 08• IceCube now 0.5 km3

• Complete in 2011

Drilling

Hose reel & tower,

Drill Camp

DOM deployment

Photo: James Roth, Dec 8, 2007

IceTop

Photo: Jim Haugen

Nov 23, 2007

Photos: Jim Haugen

Cables

Photo: Justin Vandenbroucke

ICL: IceCube Laboratory

and Data Center• Commissioned for

operation in January 2007.

• 17 racks of computers

• Power: 60 kW total for full IceCube

• Initiate runs and monitor detector from North

• Filtered data sent by satellite

• Ethan, Tex on site

1500

2500

Plan low energy core for IceCube;will replace AMANDA

AMANDA

Deep Core

Concept: define fiducial volume. Contained vertex with no hits in outer “veto” region is a neutrino candidate. Opens some phase space for downward neutrinos.

Dust layer

Very clear ice

2008-09 plan

2 test tanksDeployed Dec 03

?

?

?

??

New string postions

Standard IceCube

36

Inner core- Consists of 6 specially configured strings between 7 standard IceCube strings-Special strings have 50 DOMs, 7 m spacing below dust layer- Lower E threshold

Status

• IceCube construction & operation– Drill season: Nov-Dec-Jan– Commission new detectors: Feb-March– Start new science run April, continue through drilling

• 2007 run– 22 strings, 26 surface stations, 05/07 to 03/08– Analysis underway, some results available

• 2008– 40 strings, 40 surface stations, 04/08 to 03/09– Running now, filtered data sent by satellite to UW

Plans

• 08/09 season – Reductions due to fuel costs & NSF budget– +16 to 19 strings; +19 IceTop stations– Includes first special string of inner core– Start IC56 science run April, 2009

• 09/10 season– Plan to install 15 + 5 strings– Complete inner core with 5 special strings

• 10/11 season to complete IceCube construction