2000-2006 AMANDA-II Point Source Search Results

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2000-2006 AMANDA-II Point Source Search Results

• Jim Braun
• IceCube Spring 2008 Collaboration Meeting

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m-DAQ Point Source Searches
AMANDA-II complete
Hauschildt, Steele Phys.Rev.Lett.92071102 2004
This Analysis Combine all years for best
possible sensitivity Final sample will also be
utilized by John K. and others
Y.-R. Wang Phys.Rev.D71077102 2005
M. Ackermann Phys.Rev.D75102001 2007
Unblinded in 2007 by J. Braun
Unblinded in 2007 by J. Braun
m-DAQ decommissioned
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Data Overview
Year Livetime
2000 197 d
2001 193 d
2002 204 d
2003 213 d
2004 194 d
2005 199.3 d
2006 187 d
Total 3.8 Yr.
2000-2004 unified filtering done in Zeuthen by
Ackermann et al.
2005-2006 filtered in Madison with a very similar
configuration.

• Data and neutrino simulation available in Madison

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Event Selection

• 20M events at L3
• Use cuts from 5 year analysis
• Smoothness
• Paraboloid error
• Up/down likelihood ratio
• Use an SVM-based cut for d lt 1.5o
• 6595 total events

• Much more information available on analysis web
  page
• http//www.icecube.wisc.edu/jbraun/combined_po
  int_source

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Event Selection
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Search Method

• Apply unbinned maximum likelihood search method
• Use paraboloid error estimate as a measure of
  reconstruction uncertainty
• Use event energy (Nch) to separate signal from
  atmospheric neutrinos
• Method details described in internal report
• http//internal.icecube.wisc.edu/reports/data/icec
  ube/2008/04/001/icecube_200804001_v2.pdf

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Search Method
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Sensitivity
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Unblinded Skymap

• Short, short summary We see nothing

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Analysis
What did we do with the data? 1. All-sky
search 2. Search based on a list of
candidates 3. Milagro stacking search 4.
Search for autocorrelation
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All-Sky Search
5yr max significance 3.74s ? 2.8s
95 of 100 data sets randomized in RA have a
significance ³ 3.38s
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Source List Search
Selected Sources

• The Crab
• Significance decreases
• Still a minor upward fluctuation
• Upward Fluctuations
• LS I 61 303
• Geminga
• Downward Fluctuations
• Mrk 421

Source m90 P-value
Crab 4.62 0.10
MGRO J201937 4.14 0.077
Mrk 421 0.67 0.82
Mrk 501 2.97 0.22
LS I 61 303 9.62 0.03
Geminga 10.72 0.0086
The probability of obtaining p 0.0086 for at
least one of the 26 sources is 20
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Experimental Limits
Energy Range (90) 1 TeV 3 PeV
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Milagro Stacking Search
A. Abdo et al. Proc. First Glast Symposium

• Apply stacking search to 6 Milagro sources with
  gt5s pretrial significance
• Exclude PWN sources (Crab, Geminga)
• Use method developed by HiRes to perform our
  likelihood search simultaneously for all Milagro
  source locations
• Improves per-source flux sensitivity and
  discovery potential by a factor of 4 compared to
  a fixed-point search for any of the six sources

R.U. Abbasi, et al. Astrophys. J., 636 680
(2006)
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Milagro Stacking Search
Halzen, Kappes, OMurchada arXiv0803.0314
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Milagro Stacking Search
Halzen, Kappes, OMurchada arXiv0803.0314
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Autocorrelation Search

• Search for event clustering at angular scales
  comparable to detector resolution
• Signal scenario A number of small event clusters
• Method Count the number of event pairs given a
  maximum angular separation and minimum Nch and
  compare to distributions from data with
  randomized RA

• Max significance 1.6s
• 99 out of 100 sets of randomized data have a max
  significance of 1.6s or greater

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Systematics

• Systematics will be similar to those from the 5
  year analysis
• ANIS predicts 8 fewer atmospheric neutrino
  events compared to NUSIM
• Include nt muon contribution?
• Systematics of unbinned analysis

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Publication

• Rapidly address systematics and get manuscript to
  collaboration as soon as possible

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Conclusions

• This analysis is a factor of 2 more sensitive
  than previous point source analysis
• We didnt see anything
• IC22, IC40 will yield substantial improvements