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ANITA-1 Analysis Update. Collaboration Phone Meeting 20 July 2009 Stephen Hoover. Imaging Interferometry. Since last meeting, I have begun summing full interferometric images Previous plot: largest cross-correlation peak from each event
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ANITA-1 Analysis Update Collaboration Phone Meeting 20 July 2009 Stephen Hoover
Imaging Interferometry • Since last meeting, I have begun summing full interferometric images • Previous plot: largest cross-correlation peak from each event • Now: Average together full interferometric image from each event • Subsequent plots show the summed image from events 4,300,000 – 4,340,000 • Filtered to remove < 200 MHz, 220 – 290 MHz, > 1200 MHz
v-pol h-pol
v-pol h-pol
v-pol h-pol
Notice that the image has “stripes” Prominent strip associated with the horizon Why? What are the other stripes? V-pol Note that Solar peak is ~ 0.028 in v-pol horizon
The same stripes in the h-pol: H-pol Note that Solar peak is ~ 0.030 in h-pol horizon
Neutrino Search Cuts • Base cuts: • Run on 10% sample with no adaptive filter to search for anthropogenic sources • Add new “pseudo-bases” to my base list • Set neutrino base cuts based on shortest straight-line distance from reconstructed event to base and on smallest value of Andres’s log-likelihood-inspired metric (ELOG #469) • LL = (Δθ/σθ)2 +(Δφ/σφ)2 • σφ = 0.9°, σθ = 0.35 °
10% sample, reconstructed events using satellite filter only (no adaptive filtering) ~198,300 events plotted Misreconstructions 9
Resume adaptive filtering, but relax cross-correlation cut On next slide, plot distance of this section, and LL of this section
# neutrinos with LL < 20 : 3.6% LL < 30 : 5.2% LL < 40 : 6.8% Potential cuts Estimate volume removed by using icemc to find neutrino exit points # neutrinos with dist < 40 km : 7.8% dist < 50 km : 10.7%
Proposed cuts • Remove events with • Base LL < 30 • Base distance < 40 km • or < 150 km from McMurdo • < 150 km from South Pole • < 75 km from Mt. Vinson • This removes 11% of potential neutrinos