1. 2000-2006 AMANDA-II Point Source Search Results
Jim Braun
IceCube Spring 2008 Collaboration Meeting

2. m-DAQ Point Source Searches
AMANDA-II complete
Hauschildt, Steele: Phys.Rev.Lett.92:
2000
2001
2002
2003
2004
2005
2006
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.D71:
M. Ackermann: Phys.Rev.D75:
Unblinded in 2007 by J. Braun
Unblinded in 2007 by J. Braun
m-DAQ decommissioned

3. 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.
unified filtering done in
Zeuthen by Ackermann et al.
filtered in Madison with
a very similar configuration.
Data and neutrino simulation available in Madison

4. Event Selection Much more information available on analysis web page:
20M events at L3
Use cuts from 5 year analysis
Smoothness
Paraboloid error
Up/down likelihood ratio
Use an SVM-based cut for d < 1.5o
6595 total events
Much more information available on analysis web page:

5. Event Selection

6. 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:

7. Search Method

8. Sensitivity

9. Unblinded Skymap
Short, short summary: We see nothing

10. 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

11. All-Sky Search Max Significance Significance
3yr max significance:
3.73s  1.5s
Max Significance
d=54o, a=11.4h
3.38s
5yr max significance:
3.74s  2.8s
95 of 100 data sets randomized in RA have a significance ³ 3.38s

12. Source List Search The Crab: Upward Fluctuations:
Selected Sources
The Crab:
Significance decreases
Still a minor upward fluctuation
Upward Fluctuations:
LS I
Geminga
Downward Fluctuations:
Mrk 421
Source
m90
P-value
Crab
4.62
0.10
MGRO J
4.14
0.077
Mrk 421
0.67
0.82
Mrk 501
2.97
0.22
LS I
9.62
0.03
Geminga
10.72
0.0086
Compute limits with feldman-cousins procedure
The probability of obtaining p £
for at least one of the 26 sources is 20%

13. Experimental Limits
Energy Range (90%): 1 TeV – 3 PeV

14. Milagro Stacking Search
A. Abdo et al. Proc. First Glast Symposium
Apply stacking search to 6 Milagro sources with >5s 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., (2006)

15. Milagro Stacking Search
Halzen, Kappes, O’Murchada [arXiv: ]

16. Milagro Stacking Search
Potential IC40 Sensitivity
Halzen, Kappes, O’Murchada [arXiv: ]

17. 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
Significance
Max significance: 1.6s
99 out of 100 sets of randomized data have a max significance of 1.6s or greater
If result went the other way, I’m sure the discussion would be somewhat different

18. 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

19. Publication
Rapidly address systematics and get manuscript to collaboration as soon as possible

20. Conclusions
This analysis is a factor of 2 more sensitive than previous point source analysis
We didn’t see anything
IC22, IC40 will yield substantial improvements