d05b10017f91ddba30e23aeef0bd8b53.ppt
- Количество слайдов: 24
The Ice. Cube Neutrino Telescope Kyler Kuehn Center for Cosmology and Astro. Particle Physics The Ohio State University Novel Searches for Dark Matter CCAPP November 17, 2008
The Ice. Cube Collaboration Sweden: USA: Bartol Research Institute, Delaware Pennsylvania State University UC Berkeley UC Irvine Clark-Atlanta University of Alabama University of Maryland University of Wisconsin-Madison University of Wisconsin-River Falls Lawrence Berkeley National Lab University of Kansas Georgia Institute of Technology Southern University and A&M College, Baton Rouge University of Alaska, Anchorage The Ohio State University Uppsala Universitet Stockholm Universitet UK: Oxford University Netherlands: Germany: Universität Mainz DESY-Zeuthen Universität Dortmund Universität Wuppertal Humboldt Universität MPI Heidelberg RWTH Aachen Utrecht University Switzerland: EPFL Japan: Chiba University Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut >30 institutions, ~250 members http: //icecube. wisc. edu New Zealand: University of Canterbury
South Pole ion Am tat n-Scott S undse Skiway AMANDA Counting House Ice. Cube mp a Drill C 3
Ice. Cube Ice. Top 5
The Enhanced Hot Water Drill (EHWD) r heater) ot wate rill camp (5 MW h D Hose Reel Hot water ho ses (2) Ice. Top Tanks (w/ sun shield) Solar heated Drill speeds ~ 2 m/minute Facilities ~40 hours to drill a hole ~12 hours to deploy a string Deploy: DOMs, pressure sensors, Std. Candle, dust logger, … Drill head 6
EHWD in Action
A New Astronomical Messenger Cutoff determined by e+e- threshold for stellar IR photons diffuse, GRB Cutoff determined by μG galactic B field AGN, TD Neutrinos open a new window onto astrophysical processes in ways which no other particle can
Neutrino Detection • Neutrino interacts with a nucleon and produces a lepton • Lepton emits Cherenkov light as it travels through ice (in 41° cone) • Light is detected by Digital Optical Module (DOM) • 35 cm pressure vessel surrounding a 25 cm Photomultiplier • 400 ns recording time • 3 channels gives a 14 bit dynamic range • 1 - 2% of DOMs fail during freeze-in • 15 year survival probability 96% 9
Neutrino Event Identification Cascades Tracks Ice. Cube Angular Resolution < 1° Muon from IC 40 Data Track-Like Ice. Cube AMANDA Cascade-Like Ice. Cube AMANDA Time Resolution (nsec) 2 5 -7 Energy Resolution (log 10 E) 0. 3 – 0. 4 Energy Resolution (log 10 E) 0. 18 2π Field of View 4π 4π Field of View 2π 10
A Wealth of Science AGNs, GRBs: cosmic accelerators? Diffuse Sources ? Point Sources DM: Solar WIMPs (see subsequent talks) GZK/UHE Supernovae CRs 11
AMANDA Datasets Most published physics results are from AMANDA completed 2000 completed 1997 In 2006 AMANDA was merged into Ice. Cube. Year 2000 2001 2002 2003 2004 2005 2006 Total* Livetime 197 d 193 d 204 d 213 d 194 d 199 d 187 d 3. 8 years * Not including AMANDA B-10 (1997 -1999) 12
Ice. Cube Datasets #Strings Year Run Length CR Rate rate IC 1 2005 164 days 5 Hz ~0. 01/day IC 9 2006 137 days 80 Hz ~ 1. 5/day IC 22 2007 319 days 550 Hz ~ 20/day IC 40 2008 ~ 1 year 1400 Hz IC 80 2011 10 years 1650 Hz + + + ~ 200/day IC 1 IC 9 IC 22 IC 40 13
Cosmic Ray Flux Measurement • Ice. Cube can measure the “background” cosmic ray μ flux • Allows evaluation of detector simulation as well as – Cosmic ray flux and composition around the knee – Prompt contribution to muon flux from charm production Atm. Astrophysical Cosmic Ray 14
IC 9 Diffuse Analysis E-3. 7 E-2 • Search for excess of unresolved neutrinos from astrophysical sources • Use energy based variables (NCh) to separate astrophysical from atmospheric • Preliminary sensitivity: E-2 d. N/d. E < 1. 4 x 10 -7 Ge. V/cm 2/s/sr • Roughly comparable to limit from AMANDA combined 4 -year limit Most stringent AMANDA limits: ≤ 106 Ge. V - E-2 d. N/d. E < 9 x 10 -8 [Ap. J 675, 1014, (2008)] > 106 Ge. V - E-2 d. N/d. E < 7. 4 x 10 -8 [Phys. Rev. D 76, 042008 (2007)] 15
Point Source Search Detector (Years) Energy (Te. V) Live Time (days) AMANDA B-10 (1997 -1999) 1 - 1000 623 AMANDA-II (2000 -2004) 1. 6 - 2600 1001 AMANDA-II (2000 -2006) 1. 6 -2600 1387 Ice. Cube 22 (2007) 5 - 5000 270 Ice. Cube 22 + AMANDA 0. 1 - 10 1657* * Livetime varies for specific scenarios Atm. • Search for excess of astrophysical neutrinos from a common direction over the background of atmospheric neutrinos from the Northern hemisphere 16
Ice. Cube Point Source Searches IC 9 • 26 a priori source locations • 60% of random datasets had a sigma higher than 3. 35 no excess seen C. Finley et al. ar. Xiv: 0711. 0353 [astro-ph] p. 107 -110 • Unbinned likelihood + energy information • Hottest spot at r. a. 153º, dec. 11º • p‐value (pre-trials): 7× 10‐ 7 (4. 8σ) • p‐value (post-trials) 1. 34% (2. 2σ) • Consistent with background fluctuation IC 22 17
AMANDA ν Ice. Cube CGRO γ, ν A Distant GRB IPN Satellites (Fermi, Swift, HETE, . . . ) GRB timing/localization information from correlations among satellites
GRBs in AMANDA & Ice. Cube • AMANDA Cascade (Rolling) Cascade (Trig & Roll) R 03 b: Supranova model WB 03: Waxman-Bahcall model R 03 a: Choked Burst model MN 06: Murase Nagataki model 06 06 MN MN R 03 a 3 3 WB 0 search – search • Over 400 GRBs in Northern Hemisphere – Cascade search • Triggered search for 73 GRBs in both hemispheres • Rolling search for 20012003 • Ice. Cube – 93 SWIFT bursts during IC 22 – GRB 080319 B: brightest (optical) burst ever • ~0. 1 events predicted in IC 22 using fireball model • ~1 event predicted for equivalent burst in IC 80 19
Future Plans • Deep Core (see subsequent talks) – Greatly enhances Ice. Cube sensitivity to lower energy ’s Dust concentration • Lower mass solar WIMPs • Atmospheric neutrinos – Six new strings • 60 high QE DOMs in clear ice • First string deployed 08/09, • Remaining strings deployed 09/10 • Multi-messenger astronomy – Correlations with ROTSE, AGILE, MAGIC, and LIGO • New Technologies Very clear ice – 3 Prototype digital radio strings deployed with Ice. Cube strings – 4 Hydrophones deployed above Ice. Cube D. Cowen, Neutrino 2008 20
Optional Slides
Solar Physics • Ice. Top is sensitive to ~Ge. V particles emitted by the Sun during outburst • Monitor Ice. Top tanks rates – Can extract energy spectrum in 1 - 10 Ge. V region • Paper in preparation Ice. Top Counting Rate (Hz) Dec. 13, 2006 Solar outburst seen by international monitoring network 22
CR Moon Shadow • Select well reconstructed tracks and look in angular bins Real Moon Obs. Exp. Dummy Moons (°) • See a 4 deficit in the direction of the moon in 3 mos. of IC 40 data • Independent method of calibrating Ice. Cube’s angular resolution 23
Flux Limits for Point Sources
d05b10017f91ddba30e23aeef0bd8b53.ppt