IAU Sydney

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Particle Astronomy from Antarctica Per Olof
Hulth Stockholm University
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Why Particle Astronomy from Antarctica?

• Difficult logistics
• No continues access during the year
• Cold and expensive
• Long time to build up large experiment

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Antarctic platform

• 24 hours coverage of astronomical objects
• Largest ice sheet with very transparent ice
• Unique wind conditions at high altitudes
• Low magnetic field cut off for cosmic charged
  particles
• Possibility to combine large surface detectors
  with neutrino telescopes in the ice
• South Pole special with the sources at constant
  zenith angles

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One large common question to answer for Particle
Astronomy from Antarctica
From where are the cosmic rays coming? Medium
energy Supernovas? Super High energy GRB? AGN? ??
LHC
Galactic?
Extra galactic?
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What are the sources of the Cosmic rays?
?
Some new physics?
Galactic?
Galactic?
Extra galactic?
Extra galactic?
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Cosmic ray investigations

• Determine the chemical composition and energy
  dependence of CR
• Detect the incoming CR before interacting in the
  atmosphere (Balloon flights and space flights)
• Only one particle at 1015 eV/m2 and year! Direct
  detection possible up to 1015 eV. Above 1015 eV
  using large air shower detectors at surface. But
  identification of primary particle depending on
  simulations of the shower development.
• Detect CR sources by neutrino production at the
  source.

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Dark matter detection by neutrinos
Sun
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Different projects in Antarctica

• Balloon Cosmic ray detectors
• CREAM
• Tiger
• ATIC
• TRACER
• Polar Patrol Balloon (PPB)
• Surface Cosmic ray detectors
• SPASE
• IceTop

• Neutrino Cherenkov telescopes
• AMANDA
• IceCube
• Neutrino radio telescopes
• Rice
• Anita

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Balloons

• NASA is using McMurdo as a base for launching
  Balloons for altitudes up to 37km
• Long duration flights (LDF) up to three weeks
• Ultra Long duration flights (ULDF) up to 100
  days.
• Only 5-10 grams/cm2 of the atmosphere remains.

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Balloon Cosmic ray detectors

• ATIC 1010 - 1014 eV H - Fe
• CREAM 1012 - 5 1015 eV H - Fe
• TIGER 108 - 1010 eV Fe - Zr
• TRACER - 1014 eV O - Fe
• Polar Patrol Balloon (PPB) 1010 - 1012
  eV electrons

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CREAM
CREAM
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ATIC
19 days of scientific mission Dec 02 - Jan.03
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(No Transcript)
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Tiger
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Polar Patrol Ballon (PPB)
Detector launched from Syowa station See poster
2013 IAU00287 by Toii Shoji
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Messengers of Astronomy
Only neutrinos cover the whole energy range
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Neutrino fluxes from Cosmic ray sources
log(E2 ? Flux)
pp core AGN
p? blazar jet
Top-Bottom model
Various recent models for transient sources
GRB (WB)
3 6
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log(E/GeV)
TeV PeV EeV
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Estimation of diffuse neutrino flux
MPR
WB
Atmospheric neutrinos
Demands km3 size detectors!!
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Neutrino telescopes

• Needs large volumes of optical transparent
  material gt ice sheet!

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Detection of ?e ,?? , ??
Electromagnetic and hadronic cascades
O(km) long muon tracks
? 15 m
5 m
direction determination by cherenkov light timing
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Measured Ice properties at South Pole
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AMANDA
The worlds largest running neutrino telescope
situated at the South Pole
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South Pole
Dark sector
Skiway
AMANDA
Dome
IceCube
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AMANDA-II event 2000

• AMANDA observes about 3-4 atmospheric
  neutrinos/day in a atmospheric muon background
  106 times larger.

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AMANDA - deployment
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Atmospheric muons in AMANDA-II
Atmospheric muons and neutrinos AMANDAs test
beams
much improved simulation ...but data 30 higher
than MC ... ? normalize to most vertical
bin Systematic errors ? 10 scattering (20m
_at_ 400nm) absorption (110m _at_
400nm) ? 20 optical module sensitivity ? 10
refreezing of ice in hole
PRELIMINARY
threshold energy 40 GeV (zenith averaged)
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Atmospheric n's in AMANDA-II
? neural network energy reconstruction ?
regularized unfolding
measured atmospheric neutrino spectrum
? spectrum up to 100 TeV ? compatible with Frejus
data presently no sensitivity to LSND/Nunokawa
prediction of dip structures between 0.4-3 TeV
1 sigma energy error
In future, spectrum will be used to study excess
due to cosmic ?s
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Point source search in AMANDA II
Search for excess events in sky bins for up-going
tracks
? 697 events observed above horizon ? 3
non-neutrino background for ? gt 5 ? cuts
optimized in each declination band
PRELIMINARY
above horizonmostly fake events
? sky subdivided into 300 bins (7x7) no
clustering observed
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IceCube

• 80 Strings
• 4800 PMT
• Instrumented volume 1 km3 (1 Gt)
• IceCube is designed to detect neutrinos of all
  flavors at energies from 107 eV (SN) to 1020 eV

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Status of IceCube

• 15 M approved for Fy02
• 25 M for FY03
• 295 M in presidents budget for FY04 (should
  cover the full detector plus 4 years of running)
• New hot water drill to be sent to South Pole
  03/04
• Up to 6 IceCube strings to be deployed 04/05 (and
  then up to 16 strings per year)

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IceCubeTop View
Counting House
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Finished DOM Ready to Pack and Test
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Simulated nm-events in IceCube
Eµ10 TeV
Eµ6 PeV
Measure muon energy at the detector by counting
the number of fired PMTs.
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Complementarity (point sources)
E ?lt 100 TeV
Mediterranean (ocean) Antares, Nestor, 1 km3 ...
South Pole (ice) AMANDA, ICECUBE
galactic center in middle
dots distribution of gamma ray bursts (GRBs)
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SPASE
SPASE is an air shower detector at the South Pole
for showers above 5 1013 eV. SPASE measure the
electromagnetic component of the shower AMANDA
the muon component! Unique combination!!
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AMANDA-SPASE

• Plot muons vs. electrons
• Transformed axes correspond to mass and energy

Iron
Protons
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IceTop - IceCube

• Particle astrophysics
• using surface/under-ice coincidences as a novel
  probe of primary cosmic-ray spectrum to 1018 eV
• Calibration
• with tagged muons
• Veto
• of certain backgrounds for n signals

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EeV nm Detection in IceCube with shower veto
m

Threshold 1017 eV to veto this background
This background for EeV events can be vetoed by
detecting the fringe of the coincident
horizontal air shower in an array of water
Cherenkov detectors (cf. Ave et al., PRL 85
(2000) 2244, analysis of Haverah Park)

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Radio detectors
Very high energy cascades emits Cherenkov
radiation in radio wave length Larger attenuation
length than optical -gt larger volumes But higher
energy threshold (gt 10 PeV)
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RICE South Pole
Antennas deployed down to a few hundred meters in
the AMANDA holes. Testing since 1996 Preparing
an application for a larger RICE together with
IceCube
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ANITA
(Antarctic Impulsive Transient Array)
Flight in 2006
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Summary

• Antarctica as a very successful platform for
  particle astronomy!