1. IceCube: Neutrino telescope & cosmic-ray detector
IceCube at U. Delaware
Cosmic-ray physics
IceCube/IceTop
Future plans
26 March Tom Gaisser
Photo: James Roth

2. The animation illustrates an air shower
26 March 2008
Tom Gaisser

3. Energy spectrum of cosmic rays
Range of IceTop/IceCube
DIRECT
Air
Showers
12 decades of energy
Two steady components
Galactic
Extra-galactic
Sporadic effects of solar activity
Solar cosmic rays (e.g. from flares)
Modulation of galactic component
Galactic
Extra-galactic
Tevatron
LHC
26 March 2008
Tom Gaisser

4. Solar energetic particles
Solar flare of Dec 13, 2006
Galactic CR
suppressed by solar activity
Observation by
PAMELA
Satellite Experiment
Solar energetic particles
26 March 2008
Tom Gaisser

5. Active Galactic Nuclei as cosmic accelerators?
Auger Collaboration:
20 of 27 events with E > 57 EeV
are within 3.1 degrees of an AGN
less than 75 Mpc away.
Centaurus-A (4 Mpc, white dot) is
especially prominent.
( 57 EeV = 0.01 Joule )
( 1 Mpc = 3 million light years )
Could be from AGN or from
other sources associated with
concentrations of galaxies
Are they protons (as expected
if they point to distant sources)?
26 March 2008
Tom Gaisser

6. Acceleration by supernova remnants: ‘standard model’ of galactic cosmic rays
Forward shock
u1 ~ 4/3 V
Particle with E1
E2 = x E1
Contact discontinuity, V
SN ejecta
Shocked
ISM
Unshocked ISM
Supernova progenitor
SNR expands into ISM
with velocity V~ 104 km/s.
Drives forward shock at 4/3 V
TSN ~ 1000 yrs before slowdown
Emax ~ Z x 100 TeV
26 March 2008
Tom Gaisser

7. Filamentary structure of X-ray emission of young SNRs:
Chandra
Cassiopeia A
SN 1006
Filamentary structure of X-ray emission
of young SNRs:
Evidence for amplification, B ~ 100 mG
Berezhko&Volk, OG111
26 March 2008
Tom Gaisser

8. Berezhko & Völk: global fit to data with Emax = Z x 3 x 1015 eV
arXiv 30
Acceleration, propagation
depend on B: rgyro = R/B
Rigidity, R = E/Ze
Ec(Z) ~ Z Rc
Slope change should occur within factor of 30 in energy
With characteristic pattern of increasing A
26 March 2008
Tom Gaisser

9. Berezhko & Völk Model galactic component Transition predicted:
Subtract from observed
to get extragalactic
Heavies at end of galactic
Extra-galactic protons
Transition predicted:
to eV 30
26 March 2008
arXiv: v1 [astro-ph]
Tom Gaisser

10. Composition with air showers
heavy
nucleus
proton
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
26 March 2008
Tom Gaisser

11. Composition with air shower experiments
Sketch of ground array with
fluorescence detector – Auger Project
Telescope Array realize this concept
Composition with air shower experiments
m / e
Deep IceCube
IceTop
Xmax
1000 Km2 detectors: > EeV
Auger & Telescope Array
Planning low energy extensions
Km scale detectors: PeV to EeV
26 March 2008
Tom Gaisser

12. Depth of maximum via air Cherenkov or fluorescence
1018 eV proton
Depth of IceTop
26 March 2008
Tom Gaisser

13. A coincident event
E0 ~ 30 PeV
26 March 2008
Tom Gaisser

14. IC22 Events ( Red hits = early; yellow/green/blue = later )
IceCube DOM locations blue, AMANDA OM locations red
Downward cosmic-ray event (“muon bundle”)
Upward candidate n event

15. Cosmic-ray physcis with IceCube
5 x 1017 eV
Coincident events
Measure signal in IceTop
Compare to signal in deep ice
Infer primary composition
Goal: find transition: galactic / extra-galactic sources
Energy range: <1015  <1018 eV
Calibration / partial veto for deep IceCube
26 March 2008
Tom Gaisser

16. IceTop Photo: James Roth, Dec 8, 2007 Photo: Jim Haugen Nov 23, 2007
26 March 2008
Tom Gaisser

17. IceTop tanks 2 tanks per station 2 DOMs per tank
1 tank hit  muon, e or g
Both tanks hit  air shower
2 DOMs per tank
1 HG, 1 LG for dynamic range
26 March 2008
Tom Gaisser

18. Muon telescope relates peak of calibration run to VEM
ICRC Contribution of L. Demirörs
All events
Vertical muons
(tagged with muon telescope)
Full Spectrum
Muon Peak
Vertical
Yellow:
Normal
un-triggered
calibration
run
Serap ~Jan 25, 2008
Blue: signals in coincidence
with muon telescope
26 March 2008
Tom Gaisser

19. IceTop Detector 0.9 m 2 m Diffusely reflecting liner Tank responds to
Cherenkov light from
charged particles in
tank
2 m
0.9 m
Diffusely reflecting liner
26 March 2008
Tom Gaisser

20. Dec 13, 2006 GLE observed in IceTop monitoring stream
Paul Evenson October 2007

21. Lateral distribution
Ne fitted with NKG
Energy deposition (VEM)
--different shape
Biggest energy deposition is from converting g with E>10 MeV
F. Kislat, S. Klepser, A. Van Overlooop
icecube/
26 March 2008
Tom Gaisser

22. Spectrum Stefan Klepser preliminary Reconstructed assuming Fe
Reconstructed assuming p
Spectrum
Reconstructed assuming Fe
Reconstructed assuming mixed
Stefan Klepser
preliminary
Note: lightly shaded points
are in threshold region
where results of
unfolding algorithm are
not meaningful
26 March 2008
Tom Gaisser

23. IceCube deployment 2005-2011 2004 / 05 2005 / 06 2006 / 07 2007 / 08
AMANDA 78
IceCube string and IceTop station deployed 01/05
Deployed in 07 / 08 77 75 76 70 69 68 63 62 61 60 53 54 52 74 73 71 72
2004 / 05
IceCube string and IceTop station deployed 12/05 – 01/06 67 66 65 64
2005 / 06 58 59 57 55 56
IceTop station only 2006 50
2006 / 07 49 48
Plan for 08/09
2560 DOMs deployed to date
3 more seasons planned
Crucial planning period during the next 4 – 6 months 47
IceCube string and IceTop station deployed 12/06 – 01/07 44 45 46 39 40 38
2007 / 08
IceTop station only in 06 / 07 30 29 21
26 March 2008
Tom Gaisser

24. IceCube at UD Budget IceTop only support will require some
Mar 31, 2008
IceTop only support
will require some
increase as MRE
ends
Budget does not
include support
for extra analysis
needed to exploit
use of IceTop for
solar/heliospheric
physics
26 March 2008
Tom Gaisser

25. People IceCube/IceTop Solar / heliospheric group: Faculty
Gaisser, Evenson, Seckel, Stanev
Research scientists
X. Bai, S. Tilav, S. Stoyanov*
Post-docs
T. Waldenmaier, P. Niessen*, S. Hussain*
Grad Students
C. Xu, B. Ruzybaev
Solar / heliospheric group:
J. Bieber, P. Evenson, J. Clem, T. Kuwabara
* Leaving in PY07
26 March 2008
Tom Gaisser