IceCube a 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 University of Oxford University Utrecht The IceCube Collaboration

The neutrino landscape Prompt ee Solar  Lines show atmospheric neutrinos + antineutrinos Slope = 3.7 RPQM for prompt from charm Bugaev et al., PRD58 (1998) Slope = 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 A K / A  and A C / A K determine magnitudes New information from MINOS relevant to  with E > TeV

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, (2003)

Angular dependence For  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 )A eff ( E ) dE Earth absorption – 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 60 o ! 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 formation A common phenomenon on both stellar & galactic scales: Matter falls onto black hole or neutron star driving collimated, relativistic jets perpendicular 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/

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. Woosley See astro-ph/ v2 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 AMANDA GRB models Waxman-Bahcall PRL 78 (1997) 2292 Murase-Nagataki A PRD 73 (2006) Supranova, Razzaque et al. PRL 90 (2003) Choked bursts Meszaros-Waxman PRL 87 (2001) 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 Braun Cosmo-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 TeV atmospheric neutrinos (The Economist, November, 2007) High-altitude pressure, weather from muon & IceTop counting rates High-energy cosmic rays ( 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 Air Showers Extra-galactic component ? Galactic cutoff ~ 3 x 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 proton heavy nucleus

Depth of maximum via air Cherenkov or fluorescence eV proton Depth of IceTop

Preliminary IceTop Spectrum

Composition from angular dependence of spectrum Protons onlyIron only 5-compnents

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 E primary Require consistency with angular distribution and  /e at the surface (light from muons in ice) (electrons at surface) (light from muons in ice) (electrons at surface) (light from muons in ice) (electrons at surface) Simulation for SPASE-AMANDA

An EeV event in IC40

125 m High Energy Earth Science Tom Gaisser Tokyo, June 26, 2008 Photo: James Roth IceCube photo gallery

22 strings running in strings deployed in 07 / 08 IceCube now 0.5 km 3 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 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

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

plan 2 test tanks Deployed 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, /10 season –Plan to install strings –Complete inner core with 5 special strings 10/11 season to complete IceCube construction