IceCube a new window on the Universe Muons & neutrinos Neutrino astronomy IceCube science Status &...
-
Upload
alaina-powell -
Category
Documents
-
view
217 -
download
0
Transcript of 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