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Differential Sensitivity to Extragalactic Point Sources

Richard WhiteUniversity of Leeds

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Blazars - Reminder

Active Galactic Nuclei with the Jet oriented towards Earth.90 deg

60 deg

30 deg

0 deg

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Target Blazars

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Target Blazars

z = 0.186

0.165

0.1170.071 0o 90o

-90o ~42o lat

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Effective Area

Cos(Angle)

m2

Cos(0)Cos(-1)

Cos(1)

Neutrino Energy

(GeV)

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Effective Area

PKS2155-304, 50% ERes

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Angular Resolution

Assuming constant at the moment (1o – worst case).Using IceCube geometry doesn’t work well at all!

E (GeV)

Ang. R

es.

(deg)

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Atm. Background

Use Volkova Soviet J. Nucl. Phys. 37, 784 (1980)

Function of Zenith angle

Calculate Daily Average.

Integrate over the search cone.

Rebinned to EResInside cone

Av. Source Zenith (over 2π)

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ν Production Total Solution: pp, pγ, and leptonic contributions.

Upper (very upper) limit, just pp.

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Measured γ-Ray spectrum.

Expected ν spectrum.

Kappes et al. (2006)

From γ-Rays to ν

Kelner et al. (2006)

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Measured γ-Ray spectrum.

Expected ν spectrum.

Intrinsic γ-Ray spectrum.

From γ-Rays to ν

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EBL

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Measured γ-Ray spectrum.

Expected ν spectrum.

Intrinsic γ-Ray spectrum.

From γ-Rays to ν

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Bringing it all together...

Input Eres, Emin, Emax

Input Aeff

Input Atm. Flux

Input ARes. Calc. El. vs. Time

Calc. fobs

Calc. E binsInput γ-Ray Spectrum

Apply EBL Model

Fit

Calc. Events >Ethres

Rebin to E bins

Rebin to E bins

Calc. ν Spectrum

Rebin to E bins

Calc. Source and Atm, ν in each E bin

Opt. Cone=1.585ARes

Integrate over Cone

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Cone Size

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ν Upper Limits

Ns = 29Nb = 33

Differential Flux PKS2155-304, z=0.117

Spectral Index = -2.0

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ν Upper Limits

Ns = 1.36Nb = 33

Differential Flux PKS2155-304, z=0.117

Primack(SAM,05)

Spectral Index = -2.8

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ν Upper Limits

Ns = 651 !!Nb = 29

Differential Flux 1ES1101-232, z=0.186

Spectral Index Forced to -1.1

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ν Upper Limits

Ns = 135Nb = 29

Differential Flux 1ES1101-232, z=0.186

Spectral Index Forced to -1.5

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ν Upper Limits

Ns = 26Nb = 29

Differential Flux 1ES1101-232, z=0.186

Spectral Index Forced to -2.0

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Conclusions

UPPER LIMITS obtained for several southern hemisphere blazars.

Must extend to p-γ

WORK IN PROGRESS

Even with the lowest EBL model the most distant Blazars upper limits exceed the background... but differential detection seems unlikely.

Results heavily depend on EBL... γ horizon expanding to limit the EBL with more distant sources.